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-rw-r--r--kernel/Kconfig.preempt25
-rw-r--r--kernel/Makefile6
-rw-r--r--kernel/audit.c32
-rw-r--r--kernel/auditsc.c24
-rw-r--r--kernel/cgroup.c10
-rw-r--r--kernel/exit.c2
-rw-r--r--kernel/extable.c16
-rw-r--r--kernel/fork.c16
-rw-r--r--kernel/futex.c351
-rw-r--r--kernel/latencytop.c2
-rw-r--r--kernel/notifier.c8
-rw-r--r--kernel/panic.c32
-rw-r--r--kernel/posix-cpu-timers.c12
-rw-r--r--kernel/posix-timers.c6
-rw-r--r--kernel/power/swap.c2
-rw-r--r--kernel/printk.c2
-rw-r--r--kernel/rcuclassic.c4
-rw-r--r--kernel/rcupreempt.c10
-rw-r--r--kernel/rcupreempt_trace.c10
-rw-r--r--kernel/rcutorture.c66
-rw-r--r--kernel/rcutree.c1535
-rw-r--r--kernel/rcutree_trace.c271
-rw-r--r--kernel/relay.c7
-rw-r--r--kernel/resource.c9
-rw-r--r--kernel/sched.c3
-rw-r--r--kernel/sched_clock.c6
-rw-r--r--kernel/softirq.c19
-rw-r--r--kernel/softlockup.c4
-rw-r--r--kernel/stacktrace.c11
-rw-r--r--kernel/sys.c2
-rw-r--r--kernel/time/timekeeping.c22
31 files changed, 2182 insertions, 343 deletions
diff --git a/kernel/Kconfig.preempt b/kernel/Kconfig.preempt
index 9fdba03dc1f..bf987b95b35 100644
--- a/kernel/Kconfig.preempt
+++ b/kernel/Kconfig.preempt
@@ -52,28 +52,3 @@ config PREEMPT
endchoice
-config PREEMPT_RCU
- bool "Preemptible RCU"
- depends on PREEMPT
- default n
- help
- This option reduces the latency of the kernel by making certain
- RCU sections preemptible. Normally RCU code is non-preemptible, if
- this option is selected then read-only RCU sections become
- preemptible. This helps latency, but may expose bugs due to
- now-naive assumptions about each RCU read-side critical section
- remaining on a given CPU through its execution.
-
- Say N if you are unsure.
-
-config RCU_TRACE
- bool "Enable tracing for RCU - currently stats in debugfs"
- depends on PREEMPT_RCU
- select DEBUG_FS
- default y
- help
- This option provides tracing in RCU which presents stats
- in debugfs for debugging RCU implementation.
-
- Say Y here if you want to enable RCU tracing
- Say N if you are unsure.
diff --git a/kernel/Makefile b/kernel/Makefile
index 19fad003b19..b4fdbbff5ec 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -74,10 +74,10 @@ obj-$(CONFIG_GENERIC_HARDIRQS) += irq/
obj-$(CONFIG_SECCOMP) += seccomp.o
obj-$(CONFIG_RCU_TORTURE_TEST) += rcutorture.o
obj-$(CONFIG_CLASSIC_RCU) += rcuclassic.o
+obj-$(CONFIG_TREE_RCU) += rcutree.o
obj-$(CONFIG_PREEMPT_RCU) += rcupreempt.o
-ifeq ($(CONFIG_PREEMPT_RCU),y)
-obj-$(CONFIG_RCU_TRACE) += rcupreempt_trace.o
-endif
+obj-$(CONFIG_TREE_RCU_TRACE) += rcutree_trace.o
+obj-$(CONFIG_PREEMPT_RCU_TRACE) += rcupreempt_trace.o
obj-$(CONFIG_RELAY) += relay.o
obj-$(CONFIG_SYSCTL) += utsname_sysctl.o
obj-$(CONFIG_TASK_DELAY_ACCT) += delayacct.o
diff --git a/kernel/audit.c b/kernel/audit.c
index 4414e93d875..ce6d8ea3131 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -61,8 +61,11 @@
#include "audit.h"
-/* No auditing will take place until audit_initialized != 0.
+/* No auditing will take place until audit_initialized == AUDIT_INITIALIZED.
* (Initialization happens after skb_init is called.) */
+#define AUDIT_DISABLED -1
+#define AUDIT_UNINITIALIZED 0
+#define AUDIT_INITIALIZED 1
static int audit_initialized;
#define AUDIT_OFF 0
@@ -965,6 +968,9 @@ static int __init audit_init(void)
{
int i;
+ if (audit_initialized == AUDIT_DISABLED)
+ return 0;
+
printk(KERN_INFO "audit: initializing netlink socket (%s)\n",
audit_default ? "enabled" : "disabled");
audit_sock = netlink_kernel_create(&init_net, NETLINK_AUDIT, 0,
@@ -976,7 +982,7 @@ static int __init audit_init(void)
skb_queue_head_init(&audit_skb_queue);
skb_queue_head_init(&audit_skb_hold_queue);
- audit_initialized = 1;
+ audit_initialized = AUDIT_INITIALIZED;
audit_enabled = audit_default;
audit_ever_enabled |= !!audit_default;
@@ -999,13 +1005,21 @@ __initcall(audit_init);
static int __init audit_enable(char *str)
{
audit_default = !!simple_strtol(str, NULL, 0);
- printk(KERN_INFO "audit: %s%s\n",
- audit_default ? "enabled" : "disabled",
- audit_initialized ? "" : " (after initialization)");
- if (audit_initialized) {
+ if (!audit_default)
+ audit_initialized = AUDIT_DISABLED;
+
+ printk(KERN_INFO "audit: %s", audit_default ? "enabled" : "disabled");
+
+ if (audit_initialized == AUDIT_INITIALIZED) {
audit_enabled = audit_default;
audit_ever_enabled |= !!audit_default;
+ } else if (audit_initialized == AUDIT_UNINITIALIZED) {
+ printk(" (after initialization)");
+ } else {
+ printk(" (until reboot)");
}
+ printk("\n");
+
return 1;
}
@@ -1107,9 +1121,7 @@ unsigned int audit_serial(void)
static inline void audit_get_stamp(struct audit_context *ctx,
struct timespec *t, unsigned int *serial)
{
- if (ctx)
- auditsc_get_stamp(ctx, t, serial);
- else {
+ if (!ctx || !auditsc_get_stamp(ctx, t, serial)) {
*t = CURRENT_TIME;
*serial = audit_serial();
}
@@ -1146,7 +1158,7 @@ struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask,
int reserve;
unsigned long timeout_start = jiffies;
- if (!audit_initialized)
+ if (audit_initialized != AUDIT_INITIALIZED)
return NULL;
if (unlikely(audit_filter_type(type)))
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index cf5bc2f5f9c..2a3f0afc4d2 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -1459,7 +1459,6 @@ void audit_free(struct task_struct *tsk)
/**
* audit_syscall_entry - fill in an audit record at syscall entry
- * @tsk: task being audited
* @arch: architecture type
* @major: major syscall type (function)
* @a1: additional syscall register 1
@@ -1548,9 +1547,25 @@ void audit_syscall_entry(int arch, int major,
context->ppid = 0;
}
+void audit_finish_fork(struct task_struct *child)
+{
+ struct audit_context *ctx = current->audit_context;
+ struct audit_context *p = child->audit_context;
+ if (!p || !ctx || !ctx->auditable)
+ return;
+ p->arch = ctx->arch;
+ p->major = ctx->major;
+ memcpy(p->argv, ctx->argv, sizeof(ctx->argv));
+ p->ctime = ctx->ctime;
+ p->dummy = ctx->dummy;
+ p->auditable = ctx->auditable;
+ p->in_syscall = ctx->in_syscall;
+ p->filterkey = kstrdup(ctx->filterkey, GFP_KERNEL);
+ p->ppid = current->pid;
+}
+
/**
* audit_syscall_exit - deallocate audit context after a system call
- * @tsk: task being audited
* @valid: success/failure flag
* @return_code: syscall return value
*
@@ -1942,15 +1957,18 @@ EXPORT_SYMBOL_GPL(__audit_inode_child);
*
* Also sets the context as auditable.
*/
-void auditsc_get_stamp(struct audit_context *ctx,
+int auditsc_get_stamp(struct audit_context *ctx,
struct timespec *t, unsigned int *serial)
{
+ if (!ctx->in_syscall)
+ return 0;
if (!ctx->serial)
ctx->serial = audit_serial();
t->tv_sec = ctx->ctime.tv_sec;
t->tv_nsec = ctx->ctime.tv_nsec;
*serial = ctx->serial;
ctx->auditable = 1;
+ return 1;
}
/* global counter which is incremented every time something logs in */
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index fe00b3b983a..2606d0fb4e5 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -702,7 +702,7 @@ static int rebind_subsystems(struct cgroupfs_root *root,
* any child cgroups exist. This is theoretically supportable
* but involves complex error handling, so it's being left until
* later */
- if (!list_empty(&cgrp->children))
+ if (root->number_of_cgroups > 1)
return -EBUSY;
/* Process each subsystem */
@@ -1024,7 +1024,7 @@ static int cgroup_get_sb(struct file_system_type *fs_type,
if (ret == -EBUSY) {
mutex_unlock(&cgroup_mutex);
mutex_unlock(&inode->i_mutex);
- goto drop_new_super;
+ goto free_cg_links;
}
/* EBUSY should be the only error here */
@@ -1073,10 +1073,11 @@ static int cgroup_get_sb(struct file_system_type *fs_type,
return simple_set_mnt(mnt, sb);
+ free_cg_links:
+ free_cg_links(&tmp_cg_links);
drop_new_super:
up_write(&sb->s_umount);
deactivate_super(sb);
- free_cg_links(&tmp_cg_links);
return ret;
}
@@ -2934,9 +2935,6 @@ int cgroup_clone(struct task_struct *tsk, struct cgroup_subsys *subsys,
again:
root = subsys->root;
if (root == &rootnode) {
- printk(KERN_INFO
- "Not cloning cgroup for unused subsystem %s\n",
- subsys->name);
mutex_unlock(&cgroup_mutex);
return 0;
}
diff --git a/kernel/exit.c b/kernel/exit.c
index 2d8be7ebb0f..30fcdf16737 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -1321,10 +1321,10 @@ static int wait_task_zombie(struct task_struct *p, int options,
* group, which consolidates times for all threads in the
* group including the group leader.
*/
+ thread_group_cputime(p, &cputime);
spin_lock_irq(&p->parent->sighand->siglock);
psig = p->parent->signal;
sig = p->signal;
- thread_group_cputime(p, &cputime);
psig->cutime =
cputime_add(psig->cutime,
cputime_add(cputime.utime,
diff --git a/kernel/extable.c b/kernel/extable.c
index a26cb2e1702..adf0cc9c02d 100644
--- a/kernel/extable.c
+++ b/kernel/extable.c
@@ -66,3 +66,19 @@ int kernel_text_address(unsigned long addr)
return 1;
return module_text_address(addr) != NULL;
}
+
+/*
+ * On some architectures (PPC64, IA64) function pointers
+ * are actually only tokens to some data that then holds the
+ * real function address. As a result, to find if a function
+ * pointer is part of the kernel text, we need to do some
+ * special dereferencing first.
+ */
+int func_ptr_is_kernel_text(void *ptr)
+{
+ unsigned long addr;
+ addr = (unsigned long) dereference_function_descriptor(ptr);
+ if (core_kernel_text(addr))
+ return 1;
+ return module_text_address(addr) != NULL;
+}
diff --git a/kernel/fork.c b/kernel/fork.c
index 2a372a0e206..495da2e9a8b 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -315,17 +315,20 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
file = tmp->vm_file;
if (file) {
struct inode *inode = file->f_path.dentry->d_inode;
+ struct address_space *mapping = file->f_mapping;
+
get_file(file);
if (tmp->vm_flags & VM_DENYWRITE)
atomic_dec(&inode->i_writecount);
-
- /* insert tmp into the share list, just after mpnt */
- spin_lock(&file->f_mapping->i_mmap_lock);
+ spin_lock(&mapping->i_mmap_lock);
+ if (tmp->vm_flags & VM_SHARED)
+ mapping->i_mmap_writable++;
tmp->vm_truncate_count = mpnt->vm_truncate_count;
- flush_dcache_mmap_lock(file->f_mapping);
+ flush_dcache_mmap_lock(mapping);
+ /* insert tmp into the share list, just after mpnt */
vma_prio_tree_add(tmp, mpnt);
- flush_dcache_mmap_unlock(file->f_mapping);
- spin_unlock(&file->f_mapping->i_mmap_lock);
+ flush_dcache_mmap_unlock(mapping);
+ spin_unlock(&mapping->i_mmap_lock);
}
/*
@@ -1398,6 +1401,7 @@ long do_fork(unsigned long clone_flags,
init_completion(&vfork);
}
+ audit_finish_fork(p);
tracehook_report_clone(trace, regs, clone_flags, nr, p);
/*
diff --git a/kernel/futex.c b/kernel/futex.c
index 8af10027514..b4f87bac91c 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -92,11 +92,12 @@ struct futex_pi_state {
* A futex_q has a woken state, just like tasks have TASK_RUNNING.
* It is considered woken when plist_node_empty(&q->list) || q->lock_ptr == 0.
* The order of wakup is always to make the first condition true, then
- * wake up q->waiters, then make the second condition true.
+ * wake up q->waiter, then make the second condition true.
*/
struct futex_q {
struct plist_node list;
- wait_queue_head_t waiters;
+ /* There can only be a single waiter */
+ wait_queue_head_t waiter;
/* Which hash list lock to use: */
spinlock_t *lock_ptr;
@@ -123,24 +124,6 @@ struct futex_hash_bucket {
static struct futex_hash_bucket futex_queues[1<<FUTEX_HASHBITS];
/*
- * Take mm->mmap_sem, when futex is shared
- */
-static inline void futex_lock_mm(struct rw_semaphore *fshared)
-{
- if (fshared)
- down_read(fshared);
-}
-
-/*
- * Release mm->mmap_sem, when the futex is shared
- */
-static inline void futex_unlock_mm(struct rw_semaphore *fshared)
-{
- if (fshared)
- up_read(fshared);
-}
-
-/*
* We hash on the keys returned from get_futex_key (see below).
*/
static struct futex_hash_bucket *hash_futex(union futex_key *key)
@@ -161,6 +144,45 @@ static inline int match_futex(union futex_key *key1, union futex_key *key2)
&& key1->both.offset == key2->both.offset);
}
+/*
+ * Take a reference to the resource addressed by a key.
+ * Can be called while holding spinlocks.
+ *
+ */
+static void get_futex_key_refs(union futex_key *key)
+{
+ if (!key->both.ptr)
+ return;
+
+ switch (key->both.offset & (FUT_OFF_INODE|FUT_OFF_MMSHARED)) {
+ case FUT_OFF_INODE:
+ atomic_inc(&key->shared.inode->i_count);
+ break;
+ case FUT_OFF_MMSHARED:
+ atomic_inc(&key->private.mm->mm_count);
+ break;
+ }
+}
+
+/*
+ * Drop a reference to the resource addressed by a key.
+ * The hash bucket spinlock must not be held.
+ */
+static void drop_futex_key_refs(union futex_key *key)
+{
+ if (!key->both.ptr)
+ return;
+
+ switch (key->both.offset & (FUT_OFF_INODE|FUT_OFF_MMSHARED)) {
+ case FUT_OFF_INODE:
+ iput(key->shared.inode);
+ break;
+ case FUT_OFF_MMSHARED:
+ mmdrop(key->private.mm);
+ break;
+ }
+}
+
/**
* get_futex_key - Get parameters which are the keys for a futex.
* @uaddr: virtual address of the futex
@@ -179,12 +201,10 @@ static inline int match_futex(union futex_key *key1, union futex_key *key2)
* For other futexes, it points to &current->mm->mmap_sem and
* caller must have taken the reader lock. but NOT any spinlocks.
*/
-static int get_futex_key(u32 __user *uaddr, struct rw_semaphore *fshared,
- union futex_key *key)
+static int get_futex_key(u32 __user *uaddr, int fshared, union futex_key *key)
{
unsigned long address = (unsigned long)uaddr;
struct mm_struct *mm = current->mm;
- struct vm_area_struct *vma;
struct page *page;
int err;
@@ -208,100 +228,50 @@ static int get_futex_key(u32 __user *uaddr, struct rw_semaphore *fshared,
return -EFAULT;
key->private.mm = mm;
key->private.address = address;
+ get_futex_key_refs(key);
return 0;
}
- /*
- * The futex is hashed differently depending on whether
- * it's in a shared or private mapping. So check vma first.
- */
- vma = find_extend_vma(mm, address);
- if (unlikely(!vma))
- return -EFAULT;
- /*
- * Permissions.
- */
- if (unlikely((vma->vm_flags & (VM_IO|VM_READ)) != VM_READ))
- return (vma->vm_flags & VM_IO) ? -EPERM : -EACCES;
+again:
+ err = get_user_pages_fast(address, 1, 0, &page);
+ if (err < 0)
+ return err;
+
+ lock_page(page);
+ if (!page->mapping) {
+ unlock_page(page);
+ put_page(page);
+ goto again;
+ }
/*
* Private mappings are handled in a simple way.
*
* NOTE: When userspace waits on a MAP_SHARED mapping, even if
* it's a read-only handle, it's expected that futexes attach to
- * the object not the particular process. Therefore we use
- * VM_MAYSHARE here, not VM_SHARED which is restricted to shared
- * mappings of _writable_ handles.
+ * the object not the particular process.
*/
- if (likely(!(vma->vm_flags & VM_MAYSHARE))) {
- key->both.offset |= FUT_OFF_MMSHARED; /* reference taken on mm */
+ if (PageAnon(page)) {
+ key->both.offset |= FUT_OFF_MMSHARED; /* ref taken on mm */
key->private.mm = mm;
key->private.address = address;
- return 0;
+ } else {
+ key->both.offset |= FUT_OFF_INODE; /* inode-based key */
+ key->shared.inode = page->mapping->host;
+ key->shared.pgoff = page->index;
}
- /*
- * Linear file mappings are also simple.
- */
- key->shared.inode = vma->vm_file->f_path.dentry->d_inode;
- key->both.offset |= FUT_OFF_INODE; /* inode-based key. */
- if (likely(!(vma->vm_flags & VM_NONLINEAR))) {
- key->shared.pgoff = (((address - vma->vm_start) >> PAGE_SHIFT)
- + vma->vm_pgoff);
- return 0;
- }
+ get_futex_key_refs(key);
- /*
- * We could walk the page table to read the non-linear
- * pte, and get the page index without fetching the page
- * from swap. But that's a lot of code to duplicate here
- * for a rare case, so we simply fetch the page.
- */
- err = get_user_pages(current, mm, address, 1, 0, 0, &page, NULL);
- if (err >= 0) {
- key->shared.pgoff =
- page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
- put_page(page);
- return 0;
- }
- return err;
-}
-
-/*
- * Take a reference to the resource addressed by a key.
- * Can be called while holding spinlocks.
- *
- */
-static void get_futex_key_refs(union futex_key *key)
-{
- if (key->both.ptr == NULL)
- return;
- switch (key->both.offset & (FUT_OFF_INODE|FUT_OFF_MMSHARED)) {
- case FUT_OFF_INODE:
- atomic_inc(&key->shared.inode->i_count);
- break;
- case FUT_OFF_MMSHARED:
- atomic_inc(&key->private.mm->mm_count);
- break;
- }
+ unlock_page(page);
+ put_page(page);
+ return 0;
}
-/*
- * Drop a reference to the resource addressed by a key.
- * The hash bucket spinlock must not be held.
- */
-static void drop_futex_key_refs(union futex_key *key)
+static inline
+void put_futex_key(int fshared, union futex_key *key)
{
- if (!key->both.ptr)
- return;
- switch (key->both.offset & (FUT_OFF_INODE|FUT_OFF_MMSHARED)) {
- case FUT_OFF_INODE:
- iput(key->shared.inode);
- break;
- case FUT_OFF_MMSHARED:
- mmdrop(key->private.mm);
- break;
- }
+ drop_futex_key_refs(key);
}
static u32 cmpxchg_futex_value_locked(u32 __user *uaddr, u32 uval, u32 newval)
@@ -328,10 +298,8 @@ static int get_futex_value_locked(u32 *dest, u32 __user *from)
/*
* Fault handling.
- * if fshared is non NULL, current->mm->mmap_sem is already held
*/
-static int futex_handle_fault(unsigned long address,
- struct rw_semaphore *fshared, int attempt)
+static int futex_handle_fault(unsigned long address, int attempt)
{
struct vm_area_struct * vma;
struct mm_struct *mm = current->mm;
@@ -340,8 +308,7 @@ static int futex_handle_fault(unsigned long address,
if (attempt > 2)
return ret;
- if (!fshared)
- down_read(&mm->mmap_sem);
+ down_read(&mm->mmap_sem);
vma = find_vma(mm, address);
if (vma && address >= vma->vm_start &&
(vma->vm_flags & VM_WRITE)) {
@@ -361,8 +328,7 @@ static int futex_handle_fault(unsigned long address,
current->min_flt++;
}
}
- if (!fshared)
- up_read(&mm->mmap_sem);
+ up_read(&mm->mmap_sem);
return ret;
}
@@ -385,6 +351,7 @@ static int refill_pi_state_cache(void)
/* pi_mutex gets initialized later */
pi_state->owner = NULL;
atomic_set(&pi_state->refcount, 1);
+ pi_state->key = FUTEX_KEY_INIT;
current->pi_state_cache = pi_state;
@@ -462,7 +429,7 @@ void exit_pi_state_list(struct task_struct *curr)
struct list_head *next, *head = &curr->pi_state_list;
struct futex_pi_state *pi_state;
struct futex_hash_bucket *hb;
- union futex_key key;
+ union futex_key key = FUTEX_KEY_INIT;
if (!futex_cmpxchg_enabled)
return;
@@ -607,7 +574,7 @@ static void wake_futex(struct futex_q *q)
* The lock in wake_up_all() is a crucial memory barrier after the
* plist_del() and also before assigning to q->lock_ptr.
*/
- wake_up_all(&q->waiters);
+ wake_up(&q->waiter);
/*
* The waiting task can free the futex_q as soon as this is written,
* without taking any locks. This must come last.
@@ -719,20 +686,17 @@ double_lock_hb(struct futex_hash_bucket *hb1, struct futex_hash_bucket *hb2)
* Wake up all waiters hashed on the physical page that is mapped
* to this virtual address:
*/
-static int futex_wake(u32 __user *uaddr, struct rw_semaphore *fshared,
- int nr_wake, u32 bitset)
+static int futex_wake(u32 __user *uaddr, int fshared, int nr_wake, u32 bitset)
{
struct futex_hash_bucket *hb;
struct futex_q *this, *next;
struct plist_head *head;
- union futex_key key;
+ union futex_key key = FUTEX_KEY_INIT;
int ret;
if (!bitset)
return -EINVAL;
- futex_lock_mm(fshared);
-
ret = get_futex_key(uaddr, fshared, &key);
if (unlikely(ret != 0))
goto out;
@@ -760,7 +724,7 @@ static int futex_wake(u32 __user *uaddr, struct rw_semaphore *fshared,
spin_unlock(&hb->lock);
out:
- futex_unlock_mm(fshared);
+ put_futex_key(fshared, &key);
return ret;
}
@@ -769,19 +733,16 @@ out:
* to this virtual address:
*/
static int
-futex_wake_op(u32 __user *uaddr1, struct rw_semaphore *fshared,
- u32 __user *uaddr2,
+futex_wake_op(u32 __user *uaddr1, int fshared, u32 __user *uaddr2,
int nr_wake, int nr_wake2, int op)
{
- union futex_key key1, key2;
+ union futex_key key1 = FUTEX_KEY_INIT, key2 = FUTEX_KEY_INIT;
struct futex_hash_bucket *hb1, *hb2;
struct plist_head *head;
struct futex_q *this, *next;
int ret, op_ret, attempt = 0;
retryfull:
- futex_lock_mm(fshared);
-
ret = get_futex_key(uaddr1, fshared, &key1);
if (unlikely(ret != 0))
goto out;
@@ -826,18 +787,12 @@ retry:
*/
if (attempt++) {
ret = futex_handle_fault((unsigned long)uaddr2,
- fshared, attempt);
+ attempt);
if (ret)
goto out;
goto retry;
}
- /*
- * If we would have faulted, release mmap_sem,
- * fault it in and start all over again.
- */
- futex_unlock_mm(fshared);
-
ret = get_user(dummy, uaddr2);
if (ret)
return ret;
@@ -873,7 +828,8 @@ retry:
if (hb1 != hb2)
spin_unlock(&hb2->lock);
out:
- futex_unlock_mm(fshared);
+ put_futex_key(fshared, &key2);
+ put_futex_key(fshared, &key1);
return ret;
}
@@ -882,19 +838,16 @@ out:
* Requeue all waiters hashed on one physical page to another
* physical page.
*/
-static int futex_requeue(u32 __user *uaddr1, struct rw_semaphore *fshared,
- u32 __user *uaddr2,
+static int futex_requeue(u32 __user *uaddr1, int fshared, u32 __user *uaddr2,
int nr_wake, int nr_requeue, u32 *cmpval)
{
- union futex_key key1, key2;
+ union futex_key key1 = FUTEX_KEY_INIT, key2 = FUTEX_KEY_INIT;
struct futex_hash_bucket *hb1, *hb2;
struct plist_head *head1;
struct futex_q *this, *next;
int ret, drop_count = 0;
retry:
- futex_lock_mm(fshared);
-
ret = get_futex_key(uaddr1, fshared, &key1);
if (unlikely(ret != 0))
goto out;
@@ -917,12 +870,6 @@ static int futex_requeue(u32 __user *uaddr1, struct rw_semaphore *fshared,
if (hb1 != hb2)
spin_unlock(&hb2->lock);
- /*
- * If we would have faulted, release mmap_sem, fault
- * it in and start all over again.
- */
- futex_unlock_mm(fshared);
-
ret = get_user(curval, uaddr1);
if (!ret)
@@ -974,7 +921,8 @@ out_unlock:
drop_futex_key_refs(&key1);
out:
- futex_unlock_mm(fshared);
+ put_futex_key(fshared, &key2);
+ put_futex_key(fshared, &key1);
return ret;
}
@@ -983,7 +931,7 @@ static inline struct futex_hash_bucket *queue_lock(struct futex_q *q)
{
struct futex_hash_bucket *hb;
- init_waitqueue_head(&q->waiters);
+ init_waitqueue_head(&q->waiter);
get_futex_key_refs(&q->key);
hb = hash_futex(&q->key);
@@ -1096,8 +1044,7 @@ static void unqueue_me_pi(struct futex_q *q)
* private futexes.
*/
static int fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q,
- struct task_struct *newowner,
- struct rw_semaphore *fshared)
+ struct task_struct *newowner, int fshared)
{
u32 newtid = task_pid_vnr(newowner) | FUTEX_WAITERS;
struct futex_pi_state *pi_state = q->pi_state;
@@ -1176,7 +1123,7 @@ retry:
handle_fault:
spin_unlock(q->lock_ptr);
- ret = futex_handle_fault((unsigned long)uaddr, fshared, attempt++);
+ ret = futex_handle_fault((unsigned long)uaddr, attempt++);
spin_lock(q->lock_ptr);
@@ -1196,12 +1143,13 @@ handle_fault:
* In case we must use restart_block to restart a futex_wait,
* we encode in the 'flags' shared capability
*/
-#define FLAGS_SHARED 1
+#define FLAGS_SHARED 0x01
+#define FLAGS_CLOCKRT 0x02
static long futex_wait_restart(struct restart_block *restart);
-static int futex_wait(u32 __user *uaddr, struct rw_semaphore *fshared,
- u32 val, ktime_t *abs_time, u32 bitset)
+static int futex_wait(u32 __user *uaddr, int fshared,
+ u32 val, ktime_t *abs_time, u32 bitset, int clockrt)
{
struct task_struct *curr = current;
DECLARE_WAITQUEUE(wait, curr);
@@ -1218,8 +1166,7 @@ static int futex_wait(u32 __user *uaddr, struct rw_semaphore *fshared,
q.pi_state = NULL;
q.bitset = bitset;
retry:
- futex_lock_mm(fshared);
-
+ q.key = FUTEX_KEY_INIT;
ret = get_futex_key(uaddr, fshared, &q.key);
if (unlikely(ret != 0))
goto out_release_sem;
@@ -1251,12 +1198,6 @@ static int futex_wait(u32 __user *uaddr, struct rw_semaphore *fshared,
if (unlikely(ret)) {
queue_unlock(&q, hb);
- /*
- * If we would have faulted, release mmap_sem, fault it in and
- * start all over again.
- */
- futex_unlock_mm(fshared);
-
ret = get_user(uval, uaddr);
if (!ret)
@@ -1271,12 +1212,6 @@ static int futex_wait(u32 __user *uaddr, struct rw_semaphore *fshared,
queue_me(&q, hb);
/*
- * Now the futex is queued and we have checked the data, we
- * don't want to hold mmap_sem while we sleep.
- */
- futex_unlock_mm(fshared);
-
- /*
* There might have been scheduling since the queue_me(), as we
* cannot hold a spinlock across the get_user() in case it
* faults, and we cannot just set TASK_INTERRUPTIBLE state when
@@ -1287,7 +1222,7 @@ static int futex_wait(u32 __user *uaddr, struct rw_semaphore *fshared,
/* add_wait_queue is the barrier after __set_current_state. */
__set_current_state(TASK_INTERRUPTIBLE);
- add_wait_queue(&q.waiters, &wait);
+ add_wait_queue(&q.waiter, &wait);
/*
* !plist_node_empty() is safe here without any lock.
* q.lock_ptr != 0 is not safe, because of ordering against wakeup.
@@ -1300,8 +1235,10 @@ static int futex_wait(u32 __user *uaddr, struct rw_semaphore *fshared,
slack = current->timer_slack_ns;
if (rt_task(current))
slack = 0;
- hrtimer_init_on_stack(&t.timer, CLOCK_MONOTONIC,
- HRTIMER_MODE_ABS);
+ hrtimer_init_on_stack(&t.timer,
+ clockrt ? CLOCK_REALTIME :
+ CLOCK_MONOTONIC,
+ HRTIMER_MODE_ABS);
hrtimer_init_sleeper(&t, current);
hrtimer_set_expires_range_ns(&t.timer, *abs_time, slack);
@@ -1356,6 +1293,8 @@ static int futex_wait(u32 __user *uaddr, struct rw_semaphore *fshared,
if (fshared)
restart->futex.flags |= FLAGS_SHARED;
+ if (clockrt)
+ restart->futex.flags |= FLAGS_CLOCKRT;
return -ERESTART_RESTARTBLOCK;
}
@@ -1363,7 +1302,7 @@ static int futex_wait(u32 __user *uaddr, struct rw_semaphore *fshared,
queue_unlock(&q, hb);
out_release_sem:
- futex_unlock_mm(fshared);
+ put_futex_key(fshared, &q.key);
return ret;
}
@@ -1371,15 +1310,16 @@ static int futex_wait(u32 __user *uaddr, struct rw_semaphore *fshared,
static long futex_wait_restart(struct restart_block *restart)
{
u32 __user *uaddr = (u32 __user *)restart->futex.uaddr;
- struct rw_semaphore *fshared = NULL;
+ int fshared = 0;
ktime_t t;
t.tv64 = restart->futex.time;
restart->fn = do_no_restart_syscall;
if (restart->futex.flags & FLAGS_SHARED)
- fshared = &current->mm->mmap_sem;
+ fshared = 1;
return (long)futex_wait(uaddr, fshared, restart->futex.val, &t,
- restart->futex.bitset);
+ restart->futex.bitset,
+ restart->futex.flags & FLAGS_CLOCKRT);
}
@@ -1389,7 +1329,7 @@ static long futex_wait_restart(struct restart_block *restart)
* if there are waiters then it will block, it does PI, etc. (Due to
* races the kernel might see a 0 value of the futex too.)
*/
-static int futex_lock_pi(u32 __user *uaddr, struct rw_semaphore *fshared,
+static int futex_lock_pi(u32 __user *uaddr, int fshared,
int detect, ktime_t *time, int trylock)
{
struct hrtimer_sleeper timeout, *to = NULL;
@@ -1412,8 +1352,7 @@ static int futex_lock_pi(u32 __user *uaddr, struct rw_semaphore *fshared,
q.pi_state = NULL;
retry:
- futex_lock_mm(fshared);
-
+ q.key = FUTEX_KEY_INIT;
ret = get_futex_key(uaddr, fshared, &q.key);
if (unlikely(ret != 0))
goto out_release_sem;
@@ -1502,7 +1441,6 @@ static int futex_lock_pi(u32 __user *uaddr, struct rw_semaphore *fshared,
* exit to complete.
*/
queue_unlock(&q, hb);
- futex_unlock_mm(fshared);
cond_resched();
goto retry;
@@ -1534,12 +1472,6 @@ static int futex_lock_pi(u32 __user *uaddr, struct rw_semaphore *fshared,
*/
queue_me(&q, hb);
- /*
- * Now the futex is queued and we have checked the data, we
- * don't want to hold mmap_sem while we sleep.
- */
- futex_unlock_mm(fshared);
-
WARN_ON(!q.pi_state);
/*
* Block on the PI mutex:
@@ -1552,7 +1484,6 @@ static int futex_lock_pi(u32 __user *uaddr, struct rw_semaphore *fshared,
ret = ret ? 0 : -EWOULDBLOCK;
}
- futex_lock_mm(fshared);
spin_lock(q.lock_ptr);
if (!ret) {
@@ -1618,7 +1549,6 @@ static int futex_lock_pi(u32 __user *uaddr, struct rw_semaphore *fshared,
/* Unqueue and drop the lock */
unqueue_me_pi(&q);
- futex_unlock_mm(fshared);
if (to)
destroy_hrtimer_on_stack(&to->timer);
@@ -1628,34 +1558,30 @@ static int futex_lock_pi(u32 __user *uaddr, struct rw_semaphore *fshared,
queue_unlock(&q, hb);
out_release_sem:
- futex_unlock_mm(fshared);
+ put_futex_key(fshared, &q.key);
if (to)
destroy_hrtimer_on_stack(&to->timer);
return ret;
uaddr_faulted:
/*
- * We have to r/w *(int __user *)uaddr, but we can't modify it
- * non-atomically. Therefore, if get_user below is not
- * enough, we need to handle the fault ourselves, while
- * still holding the mmap_sem.
- *
- * ... and hb->lock. :-) --ANK
+ * We have to r/w *(int __user *)uaddr, and we have to modify it
+ * atomically. Therefore, if we continue to fault after get_user()
+ * below, we need to handle the fault ourselves, while still holding
+ * the mmap_sem. This can occur if the uaddr is under contention as
+ * we have to drop the mmap_sem in order to call get_user().
*/
queue_unlock(&q, hb);
if (attempt++) {
- ret = futex_handle_fault((unsigned long)uaddr, fshared,
- attempt);
+ ret = futex_handle_fault((unsigned long)uaddr, attempt);
if (ret)
goto out_release_sem;
goto retry_unlocked;
}
- futex_unlock_mm(fshared);
-
ret = get_user(uval, uaddr);
- if (!ret && (uval != -EFAULT))
+ if (!ret)
goto retry;
if (to)
@@ -1668,13 +1594,13 @@ static int futex_lock_pi(u32 __user *uaddr, struct rw_semaphore *fshared,
* This is the in-kernel slowpath: we look up the PI state (if any),
* and do the rt-mutex unlock.
*/
-static int futex_unlock_pi(u32 __user *uaddr, struct rw_semaphore *fshared)
+static int futex_unlock_pi(u32 __user *uaddr, int fshared)
{
struct futex_hash_bucket *hb;
struct futex_q *this, *next;
u32 uval;
struct plist_head *head;
- union futex_key key;
+ union futex_key key = FUTEX_KEY_INIT;
int ret, attempt = 0;
retry:
@@ -1685,10 +1611,6 @@ retry:
*/
if ((uval & FUTEX_TID_MASK) != task_pid_vnr(current))
return -EPERM;
- /*
- * First take all the futex related locks:
- */
- futex_lock_mm(fshared);
ret = get_futex_key(uaddr, fshared, &key);
if (unlikely(ret != 0))
@@ -1747,34 +1669,30 @@ retry_unlocked:
out_unlock:
spin_unlock(&hb->lock);
out:
- futex_unlock_mm(fshared);
+ put_futex_key(fshared, &key);
return ret;
pi_faulted:
/*
- * We have to r/w *(int __user *)uaddr, but we can't modify it
- * non-atomically. Therefore, if get_user below is not
- * enough, we need to handle the fault ourselves, while
- * still holding the mmap_sem.
- *
- * ... and hb->lock. --ANK
+ * We have to r/w *(int __user *)uaddr, and we have to modify it
+ * atomically. Therefore, if we continue to fault after get_user()
+ * below, we need to handle the fault ourselves, while still holding
+ * the mmap_sem. This can occur if the uaddr is under contention as
+ * we have to drop the mmap_sem in order to call get_user().
*/
spin_unlock(&hb->lock);
if (attempt++) {
- ret = futex_handle_fault((unsigned long)uaddr, fshared,
- attempt);
+ ret = futex_handle_fault((unsigned long)uaddr, attempt);
if (ret)
goto out;
uval = 0;
goto retry_unlocked;
}
- futex_unlock_mm(fshared);
-
ret = get_user(uval, uaddr);
- if (!ret && (uval != -EFAULT))
+ if (!ret)
goto retry;
return ret;
@@ -1898,8 +1816,7 @@ retry:
* PI futexes happens in exit_pi_state():
*/
if (!pi && (uval & FUTEX_WAITERS))
- futex_wake(uaddr, &curr->mm->mmap_sem, 1,
- FUTEX_BITSET_MATCH_ANY);
+ futex_wake(uaddr, 1, 1, FUTEX_BITSET_MATCH_ANY);
}
return 0;
}
@@ -1993,18 +1910,22 @@ void exit_robust_list(struct task_struct *curr)
long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout,
u32 __user *uaddr2, u32 val2, u32 val3)
{
- int ret = -ENOSYS;
+ int clockrt, ret = -ENOSYS;
int cmd = op & FUTEX_CMD_MASK;
- struct rw_semaphore *fshared = NULL;
+ int fshared = 0;
if (!(op & FUTEX_PRIVATE_FLAG))
- fshared = &current->mm->mmap_sem;
+ fshared = 1;
+
+ clockrt = op & FUTEX_CLOCK_REALTIME;
+ if (clockrt && cmd != FUTEX_WAIT_BITSET)
+ return -ENOSYS;
switch (cmd) {
case FUTEX_WAIT:
val3 = FUTEX_BITSET_MATCH_ANY;
case FUTEX_WAIT_BITSET:
- ret = futex_wait(uaddr, fshared, val, timeout, val3);
+ ret = futex_wait(uaddr, fshared, val, timeout, val3, clockrt);
break;
case FUTEX_WAKE:
val3 = FUTEX_BITSET_MATCH_ANY;
diff --git a/kernel/latencytop.c b/kernel/latencytop.c
index 5e7b45c5692..449db466bdb 100644
--- a/kernel/latencytop.c
+++ b/kernel/latencytop.c
@@ -191,7 +191,7 @@ static int lstats_show(struct seq_file *m, void *v)
latency_record[i].time,
latency_record[i].max);
for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
- char sym[KSYM_NAME_LEN];
+ char sym[KSYM_SYMBOL_LEN];
char *c;
if (!latency_record[i].backtrace[q])
break;
diff --git a/kernel/notifier.c b/kernel/notifier.c
index 4282c0a40a5..61d5aa5eced 100644
--- a/kernel/notifier.c
+++ b/kernel/notifier.c
@@ -82,6 +82,14 @@ static int __kprobes notifier_call_chain(struct notifier_block **nl,
while (nb && nr_to_call) {
next_nb = rcu_dereference(nb->next);
+
+#ifdef CONFIG_DEBUG_NOTIFIERS
+ if (unlikely(!func_ptr_is_kernel_text(nb->notifier_call))) {
+ WARN(1, "Invalid notifier called!");
+ nb = next_nb;
+ continue;
+ }
+#endif
ret = nb->notifier_call(nb, val, v);
if (nr_calls)
diff --git a/kernel/panic.c b/kernel/panic.c
index 4d5088355bf..13f06349a78 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -21,6 +21,7 @@
#include <linux/debug_locks.h>
#include <linux/random.h>
#include <linux/kallsyms.h>
+#include <linux/dmi.h>
int panic_on_oops;
static unsigned long tainted_mask;
@@ -321,36 +322,27 @@ void oops_exit(void)
}
#ifdef WANT_WARN_ON_SLOWPATH
-void warn_on_slowpath(const char *file, int line)
-{
- char function[KSYM_SYMBOL_LEN];
- unsigned long caller = (unsigned long) __builtin_return_address(0);
- sprint_symbol(function, caller);
-
- printk(KERN_WARNING "------------[ cut here ]------------\n");
- printk(KERN_WARNING "WARNING: at %s:%d %s()\n", file,
- line, function);
- print_modules();
- dump_stack();
- print_oops_end_marker();
- add_taint(TAINT_WARN);
-}
-EXPORT_SYMBOL(warn_on_slowpath);
-
-
void warn_slowpath(const char *file, int line, const char *fmt, ...)
{
va_list args;
char function[KSYM_SYMBOL_LEN];
unsigned long caller = (unsigned long)__builtin_return_address(0);
+ const char *board;
+
sprint_symbol(function, caller);
printk(KERN_WARNING "------------[ cut here ]------------\n");
printk(KERN_WARNING "WARNING: at %s:%d %s()\n", file,
line, function);
- va_start(args, fmt);
- vprintk(fmt, args);
- va_end(args);
+ board = dmi_get_system_info(DMI_PRODUCT_NAME);
+ if (board)
+ printk(KERN_WARNING "Hardware name: %s\n", board);
+
+ if (fmt) {
+ va_start(args, fmt);
+ vprintk(fmt, args);
+ va_end(args);
+ }
print_modules();
dump_stack();
diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index 895337b16a2..157de3a4783 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -58,21 +58,21 @@ void thread_group_cputime(
struct task_struct *tsk,
struct task_cputime *times)
{
- struct signal_struct *sig;
+ struct task_cputime *totals, *tot;
int i;
- struct task_cputime *tot;
- sig = tsk->signal;
- if (unlikely(!sig) || !sig->cputime.totals) {
+ totals = tsk->signal->cputime.totals;
+ if (!totals) {
times->utime = tsk->utime;
times->stime = tsk->stime;
times->sum_exec_runtime = tsk->se.sum_exec_runtime;
return;
}
+
times->stime = times->utime = cputime_zero;
times->sum_exec_runtime = 0;
for_each_possible_cpu(i) {
- tot = per_cpu_ptr(tsk->signal->cputime.totals, i);
+ tot = per_cpu_ptr(totals, i);
times->utime = cputime_add(times->utime, tot->utime);
times->stime = cputime_add(times->stime, tot->stime);
times->sum_exec_runtime += tot->sum_exec_runtime;
@@ -311,7 +311,7 @@ static int cpu_clock_sample_group(const clockid_t which_clock,
struct task_cputime cputime;
thread_group_cputime(p, &cputime);
- switch (which_clock) {
+ switch (CPUCLOCK_WHICH(which_clock)) {
default:
return -EINVAL;
case CPUCLOCK_PROF:
diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c
index 5e79c662294..a140e44eebb 100644
--- a/kernel/posix-timers.c
+++ b/kernel/posix-timers.c
@@ -197,6 +197,11 @@ static int common_timer_create(struct k_itimer *new_timer)
return 0;
}
+static int no_timer_create(struct k_itimer *new_timer)
+{
+ return -EOPNOTSUPP;
+}
+
/*
* Return nonzero if we know a priori this clockid_t value is bogus.
*/
@@ -248,6 +253,7 @@ static __init int init_posix_timers(void)
.clock_getres = hrtimer_get_res,
.clock_get = posix_get_monotonic_raw,
.clock_set = do_posix_clock_nosettime,
+ .timer_create = no_timer_create,
};
register_posix_clock(CLOCK_REALTIME, &clock_realtime);
diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index b7713b53d07..6da14358537 100644
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -633,7 +633,7 @@ void swsusp_close(fmode_t mode)
return;
}
- blkdev_put(resume_bdev, mode); /* move up */
+ blkdev_put(resume_bdev, mode);
}
static int swsusp_header_init(void)
diff --git a/kernel/printk.c b/kernel/printk.c
index f492f1583d7..e651ab05655 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -662,7 +662,7 @@ asmlinkage int vprintk(const char *fmt, va_list args)
if (recursion_bug) {
recursion_bug = 0;
strcpy(printk_buf, recursion_bug_msg);
- printed_len = sizeof(recursion_bug_msg);
+ printed_len = strlen(recursion_bug_msg);
}
/* Emit the output into the temporary buffer */
printed_len += vscnprintf(printk_buf + printed_len,
diff --git a/kernel/rcuclassic.c b/kernel/rcuclassic.c
index 37f72e55154..e503a002f33 100644
--- a/kernel/rcuclassic.c
+++ b/kernel/rcuclassic.c
@@ -191,7 +191,7 @@ static void print_other_cpu_stall(struct rcu_ctrlblk *rcp)
/* OK, time to rat on our buddy... */
- printk(KERN_ERR "RCU detected CPU stalls:");
+ printk(KERN_ERR "INFO: RCU detected CPU stalls:");
for_each_possible_cpu(cpu) {
if (cpu_isset(cpu, rcp->cpumask))
printk(" %d", cpu);
@@ -204,7 +204,7 @@ static void print_cpu_stall(struct rcu_ctrlblk *rcp)
{
unsigned long flags;
- printk(KERN_ERR "RCU detected CPU %d stall (t=%lu/%lu jiffies)\n",
+ printk(KERN_ERR "INFO: RCU detected CPU %d stall (t=%lu/%lu jiffies)\n",
smp_processor_id(), jiffies,
jiffies - rcp->gp_start);
dump_stack();
diff --git a/kernel/rcupreempt.c b/kernel/rcupreempt.c
index 59236e8b9da..04982659875 100644
--- a/kernel/rcupreempt.c
+++ b/kernel/rcupreempt.c
@@ -551,6 +551,16 @@ void rcu_irq_exit(void)
}
}
+void rcu_nmi_enter(void)
+{
+ rcu_irq_enter();
+}
+
+void rcu_nmi_exit(void)
+{
+ rcu_irq_exit();
+}
+
static void dyntick_save_progress_counter(int cpu)
{
struct rcu_dyntick_sched *rdssp = &per_cpu(rcu_dyntick_sched, cpu);
diff --git a/kernel/rcupreempt_trace.c b/kernel/rcupreempt_trace.c
index 35c2d3360ec..7c2665cac17 100644
--- a/kernel/rcupreempt_trace.c
+++ b/kernel/rcupreempt_trace.c
@@ -149,12 +149,12 @@ static void rcupreempt_trace_sum(struct rcupreempt_trace *sp)
sp->done_length += cp->done_length;
sp->done_add += cp->done_add;
sp->done_remove += cp->done_remove;
- atomic_set(&sp->done_invoked, atomic_read(&cp->done_invoked));
+ atomic_add(atomic_read(&cp->done_invoked), &sp->done_invoked);
sp->rcu_check_callbacks += cp->rcu_check_callbacks;
- atomic_set(&sp->rcu_try_flip_1,
- atomic_read(&cp->rcu_try_flip_1));
- atomic_set(&sp->rcu_try_flip_e1,
- atomic_read(&cp->rcu_try_flip_e1));
+ atomic_add(atomic_read(&cp->rcu_try_flip_1),
+ &sp->rcu_try_flip_1);
+ atomic_add(atomic_read(&cp->rcu_try_flip_e1),
+ &sp->rcu_try_flip_e1);
sp->rcu_try_flip_i1 += cp->rcu_try_flip_i1;
sp->rcu_try_flip_ie1 += cp->rcu_try_flip_ie1;
sp->rcu_try_flip_g1 += cp->rcu_try_flip_g1;
diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c
index 85cb90588a5..b3106552210 100644
--- a/kernel/rcutorture.c
+++ b/kernel/rcutorture.c
@@ -39,6 +39,7 @@
#include <linux/moduleparam.h>
#include <linux/percpu.h>
#include <linux/notifier.h>
+#include <linux/reboot.h>
#include <linux/freezer.h>
#include <linux/cpu.h>
#include <linux/delay.h>
@@ -108,7 +109,6 @@ struct rcu_torture {
int rtort_mbtest;
};
-static int fullstop = 0; /* stop generating callbacks at test end. */
static LIST_HEAD(rcu_torture_freelist);
static struct rcu_torture *rcu_torture_current = NULL;
static long rcu_torture_current_version = 0;
@@ -136,6 +136,30 @@ static int stutter_pause_test = 0;
#endif
int rcutorture_runnable = RCUTORTURE_RUNNABLE_INIT;
+#define FULLSTOP_SIGNALED 1 /* Bail due to signal. */
+#define FULLSTOP_CLEANUP 2 /* Orderly shutdown. */
+static int fullstop; /* stop generating callbacks at test end. */
+DEFINE_MUTEX(fullstop_mutex); /* protect fullstop transitions and */
+ /* spawning of kthreads. */
+
+/*
+ * Detect and respond to a signal-based shutdown.
+ */
+static int
+rcutorture_shutdown_notify(struct notifier_block *unused1,
+ unsigned long unused2, void *unused3)
+{
+ if (fullstop)
+ return NOTIFY_DONE;
+ if (signal_pending(current)) {
+ mutex_lock(&fullstop_mutex);
+ if (!ACCESS_ONCE(fullstop))
+ fullstop = FULLSTOP_SIGNALED;
+ mutex_unlock(&fullstop_mutex);
+ }
+ return NOTIFY_DONE;
+}
+
/*
* Allocate an element from the rcu_tortures pool.
*/
@@ -199,11 +223,12 @@ rcu_random(struct rcu_random_state *rrsp)
static void
rcu_stutter_wait(void)
{
- while (stutter_pause_test || !rcutorture_runnable)
+ while ((stutter_pause_test || !rcutorture_runnable) && !fullstop) {
if (rcutorture_runnable)
schedule_timeout_interruptible(1);
else
schedule_timeout_interruptible(round_jiffies_relative(HZ));
+ }
}
/*
@@ -599,7 +624,7 @@ rcu_torture_writer(void *arg)
rcu_stutter_wait();
} while (!kthread_should_stop() && !fullstop);
VERBOSE_PRINTK_STRING("rcu_torture_writer task stopping");
- while (!kthread_should_stop())
+ while (!kthread_should_stop() && fullstop != FULLSTOP_SIGNALED)
schedule_timeout_uninterruptible(1);
return 0;
}
@@ -624,7 +649,7 @@ rcu_torture_fakewriter(void *arg)
} while (!kthread_should_stop() && !fullstop);
VERBOSE_PRINTK_STRING("rcu_torture_fakewriter task stopping");
- while (!kthread_should_stop())
+ while (!kthread_should_stop() && fullstop != FULLSTOP_SIGNALED)
schedule_timeout_uninterruptible(1);
return 0;
}
@@ -734,7 +759,7 @@ rcu_torture_reader(void *arg)
VERBOSE_PRINTK_STRING("rcu_torture_reader task stopping");
if (irqreader && cur_ops->irqcapable)
del_timer_sync(&t);
- while (!kthread_should_stop())
+ while (!kthread_should_stop() && fullstop != FULLSTOP_SIGNALED)
schedule_timeout_uninterruptible(1);
return 0;
}
@@ -831,7 +856,7 @@ rcu_torture_stats(void *arg)
do {
schedule_timeout_interruptible(stat_interval * HZ);
rcu_torture_stats_print();
- } while (!kthread_should_stop());
+ } while (!kthread_should_stop() && !fullstop);
VERBOSE_PRINTK_STRING("rcu_torture_stats task stopping");
return 0;
}
@@ -899,7 +924,7 @@ rcu_torture_shuffle(void *arg)
do {
schedule_timeout_interruptible(shuffle_interval * HZ);
rcu_torture_shuffle_tasks();
- } while (!kthread_should_stop());
+ } while (!kthread_should_stop() && !fullstop);
VERBOSE_PRINTK_STRING("rcu_torture_shuffle task stopping");
return 0;
}
@@ -914,10 +939,10 @@ rcu_torture_stutter(void *arg)
do {
schedule_timeout_interruptible(stutter * HZ);
stutter_pause_test = 1;
- if (!kthread_should_stop())
+ if (!kthread_should_stop() && !fullstop)
schedule_timeout_interruptible(stutter * HZ);
stutter_pause_test = 0;
- } while (!kthread_should_stop());
+ } while (!kthread_should_stop() && !fullstop);
VERBOSE_PRINTK_STRING("rcu_torture_stutter task stopping");
return 0;
}
@@ -934,12 +959,27 @@ rcu_torture_print_module_parms(char *tag)
stutter, irqreader);
}
+static struct notifier_block rcutorture_nb = {
+ .notifier_call = rcutorture_shutdown_notify,
+};
+
static void
rcu_torture_cleanup(void)
{
int i;
- fullstop = 1;
+ mutex_lock(&fullstop_mutex);
+ if (!fullstop) {
+ /* If being signaled, let it happen, then exit. */
+ mutex_unlock(&fullstop_mutex);
+ schedule_timeout_interruptible(10 * HZ);
+ if (cur_ops->cb_barrier != NULL)
+ cur_ops->cb_barrier();
+ return;
+ }
+ fullstop = FULLSTOP_CLEANUP;
+ mutex_unlock(&fullstop_mutex);
+ unregister_reboot_notifier(&rcutorture_nb);
if (stutter_task) {
VERBOSE_PRINTK_STRING("Stopping rcu_torture_stutter task");
kthread_stop(stutter_task);
@@ -1015,6 +1055,8 @@ rcu_torture_init(void)
{ &rcu_ops, &rcu_sync_ops, &rcu_bh_ops, &rcu_bh_sync_ops,
&srcu_ops, &sched_ops, &sched_ops_sync, };
+ mutex_lock(&fullstop_mutex);
+
/* Process args and tell the world that the torturer is on the job. */
for (i = 0; i < ARRAY_SIZE(torture_ops); i++) {
cur_ops = torture_ops[i];
@@ -1024,6 +1066,7 @@ rcu_torture_init(void)
if (i == ARRAY_SIZE(torture_ops)) {
printk(KERN_ALERT "rcutorture: invalid torture type: \"%s\"\n",
torture_type);
+ mutex_unlock(&fullstop_mutex);
return (-EINVAL);
}
if (cur_ops->init)
@@ -1146,9 +1189,12 @@ rcu_torture_init(void)
goto unwind;
}
}
+ register_reboot_notifier(&rcutorture_nb);
+ mutex_unlock(&fullstop_mutex);
return 0;
unwind:
+ mutex_unlock(&fullstop_mutex);
rcu_torture_cleanup();
return firsterr;
}
diff --git a/kernel/rcutree.c b/kernel/rcutree.c
new file mode 100644
index 00000000000..a342b032112
--- /dev/null
+++ b/kernel/rcutree.c
@@ -0,0 +1,1535 @@
+/*
+ * Read-Copy Update mechanism for mutual exclusion
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ * Copyright IBM Corporation, 2008
+ *
+ * Authors: Dipankar Sarma <dipankar@in.ibm.com>
+ * Manfred Spraul <manfred@colorfullife.com>
+ * Paul E. McKenney <paulmck@linux.vnet.ibm.com> Hierarchical version
+ *
+ * Based on the original work by Paul McKenney <paulmck@us.ibm.com>
+ * and inputs from Rusty Russell, Andrea Arcangeli and Andi Kleen.
+ *
+ * For detailed explanation of Read-Copy Update mechanism see -
+ * Documentation/RCU
+ */
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/smp.h>
+#include <linux/rcupdate.h>
+#include <linux/interrupt.h>
+#include <linux/sched.h>
+#include <asm/atomic.h>
+#include <linux/bitops.h>
+#include <linux/module.h>
+#include <linux/completion.h>
+#include <linux/moduleparam.h>
+#include <linux/percpu.h>
+#include <linux/notifier.h>
+#include <linux/cpu.h>
+#include <linux/mutex.h>
+#include <linux/time.h>
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+static struct lock_class_key rcu_lock_key;
+struct lockdep_map rcu_lock_map =
+ STATIC_LOCKDEP_MAP_INIT("rcu_read_lock", &rcu_lock_key);
+EXPORT_SYMBOL_GPL(rcu_lock_map);
+#endif
+
+/* Data structures. */
+
+#define RCU_STATE_INITIALIZER(name) { \
+ .level = { &name.node[0] }, \
+ .levelcnt = { \
+ NUM_RCU_LVL_0, /* root of hierarchy. */ \
+ NUM_RCU_LVL_1, \
+ NUM_RCU_LVL_2, \
+ NUM_RCU_LVL_3, /* == MAX_RCU_LVLS */ \
+ }, \
+ .signaled = RCU_SIGNAL_INIT, \
+ .gpnum = -300, \
+ .completed = -300, \
+ .onofflock = __SPIN_LOCK_UNLOCKED(&name.onofflock), \
+ .fqslock = __SPIN_LOCK_UNLOCKED(&name.fqslock), \
+ .n_force_qs = 0, \
+ .n_force_qs_ngp = 0, \
+}
+
+struct rcu_state rcu_state = RCU_STATE_INITIALIZER(rcu_state);
+DEFINE_PER_CPU(struct rcu_data, rcu_data);
+
+struct rcu_state rcu_bh_state = RCU_STATE_INITIALIZER(rcu_bh_state);
+DEFINE_PER_CPU(struct rcu_data, rcu_bh_data);
+
+#ifdef CONFIG_NO_HZ
+DEFINE_PER_CPU(struct rcu_dynticks, rcu_dynticks);
+#endif /* #ifdef CONFIG_NO_HZ */
+
+static int blimit = 10; /* Maximum callbacks per softirq. */
+static int qhimark = 10000; /* If this many pending, ignore blimit. */
+static int qlowmark = 100; /* Once only this many pending, use blimit. */
+
+static void force_quiescent_state(struct rcu_state *rsp, int relaxed);
+
+/*
+ * Return the number of RCU batches processed thus far for debug & stats.
+ */
+long rcu_batches_completed(void)
+{
+ return rcu_state.completed;
+}
+EXPORT_SYMBOL_GPL(rcu_batches_completed);
+
+/*
+ * Return the number of RCU BH batches processed thus far for debug & stats.
+ */
+long rcu_batches_completed_bh(void)
+{
+ return rcu_bh_state.completed;
+}
+EXPORT_SYMBOL_GPL(rcu_batches_completed_bh);
+
+/*
+ * Does the CPU have callbacks ready to be invoked?
+ */
+static int
+cpu_has_callbacks_ready_to_invoke(struct rcu_data *rdp)
+{
+ return &rdp->nxtlist != rdp->nxttail[RCU_DONE_TAIL];
+}
+
+/*
+ * Does the current CPU require a yet-as-unscheduled grace period?
+ */
+static int
+cpu_needs_another_gp(struct rcu_state *rsp, struct rcu_data *rdp)
+{
+ /* ACCESS_ONCE() because we are accessing outside of lock. */
+ return *rdp->nxttail[RCU_DONE_TAIL] &&
+ ACCESS_ONCE(rsp->completed) == ACCESS_ONCE(rsp->gpnum);
+}
+
+/*
+ * Return the root node of the specified rcu_state structure.
+ */
+static struct rcu_node *rcu_get_root(struct rcu_state *rsp)
+{
+ return &rsp->node[0];
+}
+
+#ifdef CONFIG_SMP
+
+/*
+ * If the specified CPU is offline, tell the caller that it is in
+ * a quiescent state. Otherwise, whack it with a reschedule IPI.
+ * Grace periods can end up waiting on an offline CPU when that
+ * CPU is in the process of coming online -- it will be added to the
+ * rcu_node bitmasks before it actually makes it online. The same thing
+ * can happen while a CPU is in the process of coming online. Because this
+ * race is quite rare, we check for it after detecting that the grace
+ * period has been delayed rather than checking each and every CPU
+ * each and every time we start a new grace period.
+ */
+static int rcu_implicit_offline_qs(struct rcu_data *rdp)
+{
+ /*
+ * If the CPU is offline, it is in a quiescent state. We can
+ * trust its state not to change because interrupts are disabled.
+ */
+ if (cpu_is_offline(rdp->cpu)) {
+ rdp->offline_fqs++;
+ return 1;
+ }
+
+ /* The CPU is online, so send it a reschedule IPI. */
+ if (rdp->cpu != smp_processor_id())
+ smp_send_reschedule(rdp->cpu);
+ else
+ set_need_resched();
+ rdp->resched_ipi++;
+ return 0;
+}
+
+#endif /* #ifdef CONFIG_SMP */
+
+#ifdef CONFIG_NO_HZ
+static DEFINE_RATELIMIT_STATE(rcu_rs, 10 * HZ, 5);
+
+/**
+ * rcu_enter_nohz - inform RCU that current CPU is entering nohz
+ *
+ * Enter nohz mode, in other words, -leave- the mode in which RCU
+ * read-side critical sections can occur. (Though RCU read-side
+ * critical sections can occur in irq handlers in nohz mode, a possibility
+ * handled by rcu_irq_enter() and rcu_irq_exit()).
+ */
+void rcu_enter_nohz(void)
+{
+ unsigned long flags;
+ struct rcu_dynticks *rdtp;
+
+ smp_mb(); /* CPUs seeing ++ must see prior RCU read-side crit sects */
+ local_irq_save(flags);
+ rdtp = &__get_cpu_var(rcu_dynticks);
+ rdtp->dynticks++;
+ rdtp->dynticks_nesting--;
+ WARN_ON_RATELIMIT(rdtp->dynticks & 0x1, &rcu_rs);
+ local_irq_restore(flags);
+}
+
+/*
+ * rcu_exit_nohz - inform RCU that current CPU is leaving nohz
+ *
+ * Exit nohz mode, in other words, -enter- the mode in which RCU
+ * read-side critical sections normally occur.
+ */
+void rcu_exit_nohz(void)
+{
+ unsigned long flags;
+ struct rcu_dynticks *rdtp;
+
+ local_irq_save(flags);
+ rdtp = &__get_cpu_var(rcu_dynticks);
+ rdtp->dynticks++;
+ rdtp->dynticks_nesting++;
+ WARN_ON_RATELIMIT(!(rdtp->dynticks & 0x1), &rcu_rs);
+ local_irq_restore(flags);
+ smp_mb(); /* CPUs seeing ++ must see later RCU read-side crit sects */
+}
+
+/**
+ * rcu_nmi_enter - inform RCU of entry to NMI context
+ *
+ * If the CPU was idle with dynamic ticks active, and there is no
+ * irq handler running, this updates rdtp->dynticks_nmi to let the
+ * RCU grace-period handling know that the CPU is active.
+ */
+void rcu_nmi_enter(void)
+{
+ struct rcu_dynticks *rdtp = &__get_cpu_var(rcu_dynticks);
+
+ if (rdtp->dynticks & 0x1)
+ return;
+ rdtp->dynticks_nmi++;
+ WARN_ON_RATELIMIT(!(rdtp->dynticks_nmi & 0x1), &rcu_rs);
+ smp_mb(); /* CPUs seeing ++ must see later RCU read-side crit sects */
+}
+
+/**
+ * rcu_nmi_exit - inform RCU of exit from NMI context
+ *
+ * If the CPU was idle with dynamic ticks active, and there is no
+ * irq handler running, this updates rdtp->dynticks_nmi to let the
+ * RCU grace-period handling know that the CPU is no longer active.
+ */
+void rcu_nmi_exit(void)
+{
+ struct rcu_dynticks *rdtp = &__get_cpu_var(rcu_dynticks);
+
+ if (rdtp->dynticks & 0x1)
+ return;
+ smp_mb(); /* CPUs seeing ++ must see prior RCU read-side crit sects */
+ rdtp->dynticks_nmi++;
+ WARN_ON_RATELIMIT(rdtp->dynticks_nmi & 0x1, &rcu_rs);
+}
+
+/**
+ * rcu_irq_enter - inform RCU of entry to hard irq context
+ *
+ * If the CPU was idle with dynamic ticks active, this updates the
+ * rdtp->dynticks to let the RCU handling know that the CPU is active.
+ */
+void rcu_irq_enter(void)
+{
+ struct rcu_dynticks *rdtp = &__get_cpu_var(rcu_dynticks);
+
+ if (rdtp->dynticks_nesting++)
+ return;
+ rdtp->dynticks++;
+ WARN_ON_RATELIMIT(!(rdtp->dynticks & 0x1), &rcu_rs);
+ smp_mb(); /* CPUs seeing ++ must see later RCU read-side crit sects */
+}
+
+/**
+ * rcu_irq_exit - inform RCU of exit from hard irq context
+ *
+ * If the CPU was idle with dynamic ticks active, update the rdp->dynticks
+ * to put let the RCU handling be aware that the CPU is going back to idle
+ * with no ticks.
+ */
+void rcu_irq_exit(void)
+{
+ struct rcu_dynticks *rdtp = &__get_cpu_var(rcu_dynticks);
+
+ if (--rdtp->dynticks_nesting)
+ return;
+ smp_mb(); /* CPUs seeing ++ must see prior RCU read-side crit sects */
+ rdtp->dynticks++;
+ WARN_ON_RATELIMIT(rdtp->dynticks & 0x1, &rcu_rs);
+
+ /* If the interrupt queued a callback, get out of dyntick mode. */
+ if (__get_cpu_var(rcu_data).nxtlist ||
+ __get_cpu_var(rcu_bh_data).nxtlist)
+ set_need_resched();
+}
+
+/*
+ * Record the specified "completed" value, which is later used to validate
+ * dynticks counter manipulations. Specify "rsp->completed - 1" to
+ * unconditionally invalidate any future dynticks manipulations (which is
+ * useful at the beginning of a grace period).
+ */
+static void dyntick_record_completed(struct rcu_state *rsp, long comp)
+{
+ rsp->dynticks_completed = comp;
+}
+
+#ifdef CONFIG_SMP
+
+/*
+ * Recall the previously recorded value of the completion for dynticks.
+ */
+static long dyntick_recall_completed(struct rcu_state *rsp)
+{
+ return rsp->dynticks_completed;
+}
+
+/*
+ * Snapshot the specified CPU's dynticks counter so that we can later
+ * credit them with an implicit quiescent state. Return 1 if this CPU
+ * is already in a quiescent state courtesy of dynticks idle mode.
+ */
+static int dyntick_save_progress_counter(struct rcu_data *rdp)
+{
+ int ret;
+ int snap;
+ int snap_nmi;
+
+ snap = rdp->dynticks->dynticks;
+ snap_nmi = rdp->dynticks->dynticks_nmi;
+ smp_mb(); /* Order sampling of snap with end of grace period. */
+ rdp->dynticks_snap = snap;
+ rdp->dynticks_nmi_snap = snap_nmi;
+ ret = ((snap & 0x1) == 0) && ((snap_nmi & 0x1) == 0);
+ if (ret)
+ rdp->dynticks_fqs++;
+ return ret;
+}
+
+/*
+ * Return true if the specified CPU has passed through a quiescent
+ * state by virtue of being in or having passed through an dynticks
+ * idle state since the last call to dyntick_save_progress_counter()
+ * for this same CPU.
+ */
+static int rcu_implicit_dynticks_qs(struct rcu_data *rdp)
+{
+ long curr;
+ long curr_nmi;
+ long snap;
+ long snap_nmi;
+
+ curr = rdp->dynticks->dynticks;
+ snap = rdp->dynticks_snap;
+ curr_nmi = rdp->dynticks->dynticks_nmi;
+ snap_nmi = rdp->dynticks_nmi_snap;
+ smp_mb(); /* force ordering with cpu entering/leaving dynticks. */
+
+ /*
+ * If the CPU passed through or entered a dynticks idle phase with
+ * no active irq/NMI handlers, then we can safely pretend that the CPU
+ * already acknowledged the request to pass through a quiescent
+ * state. Either way, that CPU cannot possibly be in an RCU
+ * read-side critical section that started before the beginning
+ * of the current RCU grace period.
+ */
+ if ((curr != snap || (curr & 0x1) == 0) &&
+ (curr_nmi != snap_nmi || (curr_nmi & 0x1) == 0)) {
+ rdp->dynticks_fqs++;
+ return 1;
+ }
+
+ /* Go check for the CPU being offline. */
+ return rcu_implicit_offline_qs(rdp);
+}
+
+#endif /* #ifdef CONFIG_SMP */
+
+#else /* #ifdef CONFIG_NO_HZ */
+
+static void dyntick_record_completed(struct rcu_state *rsp, long comp)
+{
+}
+
+#ifdef CONFIG_SMP
+
+/*
+ * If there are no dynticks, then the only way that a CPU can passively
+ * be in a quiescent state is to be offline. Unlike dynticks idle, which
+ * is a point in time during the prior (already finished) grace period,
+ * an offline CPU is always in a quiescent state, and thus can be
+ * unconditionally applied. So just return the current value of completed.
+ */
+static long dyntick_recall_completed(struct rcu_state *rsp)
+{
+ return rsp->completed;
+}
+
+static int dyntick_save_progress_counter(struct rcu_data *rdp)
+{
+ return 0;
+}
+
+static int rcu_implicit_dynticks_qs(struct rcu_data *rdp)
+{
+ return rcu_implicit_offline_qs(rdp);
+}
+
+#endif /* #ifdef CONFIG_SMP */
+
+#endif /* #else #ifdef CONFIG_NO_HZ */
+
+#ifdef CONFIG_RCU_CPU_STALL_DETECTOR
+
+static void record_gp_stall_check_time(struct rcu_state *rsp)
+{
+ rsp->gp_start = jiffies;
+ rsp->jiffies_stall = jiffies + RCU_SECONDS_TILL_STALL_CHECK;
+}
+
+static void print_other_cpu_stall(struct rcu_state *rsp)
+{
+ int cpu;
+ long delta;
+ unsigned long flags;
+ struct rcu_node *rnp = rcu_get_root(rsp);
+ struct rcu_node *rnp_cur = rsp->level[NUM_RCU_LVLS - 1];
+ struct rcu_node *rnp_end = &rsp->node[NUM_RCU_NODES];
+
+ /* Only let one CPU complain about others per time interval. */
+
+ spin_lock_irqsave(&rnp->lock, flags);
+ delta = jiffies - rsp->jiffies_stall;
+ if (delta < RCU_STALL_RAT_DELAY || rsp->gpnum == rsp->completed) {
+ spin_unlock_irqrestore(&rnp->lock, flags);
+ return;
+ }
+ rsp->jiffies_stall = jiffies + RCU_SECONDS_TILL_STALL_RECHECK;
+ spin_unlock_irqrestore(&rnp->lock, flags);
+
+ /* OK, time to rat on our buddy... */
+
+ printk(KERN_ERR "INFO: RCU detected CPU stalls:");
+ for (; rnp_cur < rnp_end; rnp_cur++) {
+ if (rnp_cur->qsmask == 0)
+ continue;
+ for (cpu = 0; cpu <= rnp_cur->grphi - rnp_cur->grplo; cpu++)
+ if (rnp_cur->qsmask & (1UL << cpu))
+ printk(" %d", rnp_cur->grplo + cpu);
+ }
+ printk(" (detected by %d, t=%ld jiffies)\n",
+ smp_processor_id(), (long)(jiffies - rsp->gp_start));
+ force_quiescent_state(rsp, 0); /* Kick them all. */
+}
+
+static void print_cpu_stall(struct rcu_state *rsp)
+{
+ unsigned long flags;
+ struct rcu_node *rnp = rcu_get_root(rsp);
+
+ printk(KERN_ERR "INFO: RCU detected CPU %d stall (t=%lu jiffies)\n",
+ smp_processor_id(), jiffies - rsp->gp_start);
+ dump_stack();
+ spin_lock_irqsave(&rnp->lock, flags);
+ if ((long)(jiffies - rsp->jiffies_stall) >= 0)
+ rsp->jiffies_stall =
+ jiffies + RCU_SECONDS_TILL_STALL_RECHECK;
+ spin_unlock_irqrestore(&rnp->lock, flags);
+ set_need_resched(); /* kick ourselves to get things going. */
+}
+
+static void check_cpu_stall(struct rcu_state *rsp, struct rcu_data *rdp)
+{
+ long delta;
+ struct rcu_node *rnp;
+
+ delta = jiffies - rsp->jiffies_stall;
+ rnp = rdp->mynode;
+ if ((rnp->qsmask & rdp->grpmask) && delta >= 0) {
+
+ /* We haven't checked in, so go dump stack. */
+ print_cpu_stall(rsp);
+
+ } else if (rsp->gpnum != rsp->completed &&
+ delta >= RCU_STALL_RAT_DELAY) {
+
+ /* They had two time units to dump stack, so complain. */
+ print_other_cpu_stall(rsp);
+ }
+}
+
+#else /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */
+
+static void record_gp_stall_check_time(struct rcu_state *rsp)
+{
+}
+
+static void check_cpu_stall(struct rcu_state *rsp, struct rcu_data *rdp)
+{
+}
+
+#endif /* #else #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */
+
+/*
+ * Update CPU-local rcu_data state to record the newly noticed grace period.
+ * This is used both when we started the grace period and when we notice
+ * that someone else started the grace period.
+ */
+static void note_new_gpnum(struct rcu_state *rsp, struct rcu_data *rdp)
+{
+ rdp->qs_pending = 1;
+ rdp->passed_quiesc = 0;
+ rdp->gpnum = rsp->gpnum;
+ rdp->n_rcu_pending_force_qs = rdp->n_rcu_pending +
+ RCU_JIFFIES_TILL_FORCE_QS;
+}
+
+/*
+ * Did someone else start a new RCU grace period start since we last
+ * checked? Update local state appropriately if so. Must be called
+ * on the CPU corresponding to rdp.
+ */
+static int
+check_for_new_grace_period(struct rcu_state *rsp, struct rcu_data *rdp)
+{
+ unsigned long flags;
+ int ret = 0;
+
+ local_irq_save(flags);
+ if (rdp->gpnum != rsp->gpnum) {
+ note_new_gpnum(rsp, rdp);
+ ret = 1;
+ }
+ local_irq_restore(flags);
+ return ret;
+}
+
+/*
+ * Start a new RCU grace period if warranted, re-initializing the hierarchy
+ * in preparation for detecting the next grace period. The caller must hold
+ * the root node's ->lock, which is released before return. Hard irqs must
+ * be disabled.
+ */
+static void
+rcu_start_gp(struct rcu_state *rsp, unsigned long flags)
+ __releases(rcu_get_root(rsp)->lock)
+{
+ struct rcu_data *rdp = rsp->rda[smp_processor_id()];
+ struct rcu_node *rnp = rcu_get_root(rsp);
+ struct rcu_node *rnp_cur;
+ struct rcu_node *rnp_end;
+
+ if (!cpu_needs_another_gp(rsp, rdp)) {
+ spin_unlock_irqrestore(&rnp->lock, flags);
+ return;
+ }
+
+ /* Advance to a new grace period and initialize state. */
+ rsp->gpnum++;
+ rsp->signaled = RCU_GP_INIT; /* Hold off force_quiescent_state. */
+ rsp->jiffies_force_qs = jiffies + RCU_JIFFIES_TILL_FORCE_QS;
+ rdp->n_rcu_pending_force_qs = rdp->n_rcu_pending +
+ RCU_JIFFIES_TILL_FORCE_QS;
+ record_gp_stall_check_time(rsp);
+ dyntick_record_completed(rsp, rsp->completed - 1);
+ note_new_gpnum(rsp, rdp);
+
+ /*
+ * Because we are first, we know that all our callbacks will
+ * be covered by this upcoming grace period, even the ones
+ * that were registered arbitrarily recently.
+ */
+ rdp->nxttail[RCU_NEXT_READY_TAIL] = rdp->nxttail[RCU_NEXT_TAIL];
+ rdp->nxttail[RCU_WAIT_TAIL] = rdp->nxttail[RCU_NEXT_TAIL];
+
+ /* Special-case the common single-level case. */
+ if (NUM_RCU_NODES == 1) {
+ rnp->qsmask = rnp->qsmaskinit;
+ spin_unlock_irqrestore(&rnp->lock, flags);
+ return;
+ }
+
+ spin_unlock(&rnp->lock); /* leave irqs disabled. */
+
+
+ /* Exclude any concurrent CPU-hotplug operations. */
+ spin_lock(&rsp->onofflock); /* irqs already disabled. */
+
+ /*
+ * Set the quiescent-state-needed bits in all the non-leaf RCU
+ * nodes for all currently online CPUs. This operation relies
+ * on the layout of the hierarchy within the rsp->node[] array.
+ * Note that other CPUs will access only the leaves of the
+ * hierarchy, which still indicate that no grace period is in
+ * progress. In addition, we have excluded CPU-hotplug operations.
+ *
+ * We therefore do not need to hold any locks. Any required
+ * memory barriers will be supplied by the locks guarding the
+ * leaf rcu_nodes in the hierarchy.
+ */
+
+ rnp_end = rsp->level[NUM_RCU_LVLS - 1];
+ for (rnp_cur = &rsp->node[0]; rnp_cur < rnp_end; rnp_cur++)
+ rnp_cur->qsmask = rnp_cur->qsmaskinit;
+
+ /*
+ * Now set up the leaf nodes. Here we must be careful. First,
+ * we need to hold the lock in order to exclude other CPUs, which
+ * might be contending for the leaf nodes' locks. Second, as
+ * soon as we initialize a given leaf node, its CPUs might run
+ * up the rest of the hierarchy. We must therefore acquire locks
+ * for each node that we touch during this stage. (But we still
+ * are excluding CPU-hotplug operations.)
+ *
+ * Note that the grace period cannot complete until we finish
+ * the initialization process, as there will be at least one
+ * qsmask bit set in the root node until that time, namely the
+ * one corresponding to this CPU.
+ */
+ rnp_end = &rsp->node[NUM_RCU_NODES];
+ rnp_cur = rsp->level[NUM_RCU_LVLS - 1];
+ for (; rnp_cur < rnp_end; rnp_cur++) {
+ spin_lock(&rnp_cur->lock); /* irqs already disabled. */
+ rnp_cur->qsmask = rnp_cur->qsmaskinit;
+ spin_unlock(&rnp_cur->lock); /* irqs already disabled. */
+ }
+
+ rsp->signaled = RCU_SIGNAL_INIT; /* force_quiescent_state now OK. */
+ spin_unlock_irqrestore(&rsp->onofflock, flags);
+}
+
+/*
+ * Advance this CPU's callbacks, but only if the current grace period
+ * has ended. This may be called only from the CPU to whom the rdp
+ * belongs.
+ */
+static void
+rcu_process_gp_end(struct rcu_state *rsp, struct rcu_data *rdp)
+{
+ long completed_snap;
+ unsigned long flags;
+
+ local_irq_save(flags);
+ completed_snap = ACCESS_ONCE(rsp->completed); /* outside of lock. */
+
+ /* Did another grace period end? */
+ if (rdp->completed != completed_snap) {
+
+ /* Advance callbacks. No harm if list empty. */
+ rdp->nxttail[RCU_DONE_TAIL] = rdp->nxttail[RCU_WAIT_TAIL];
+ rdp->nxttail[RCU_WAIT_TAIL] = rdp->nxttail[RCU_NEXT_READY_TAIL];
+ rdp->nxttail[RCU_NEXT_READY_TAIL] = rdp->nxttail[RCU_NEXT_TAIL];
+
+ /* Remember that we saw this grace-period completion. */
+ rdp->completed = completed_snap;
+ }
+ local_irq_restore(flags);
+}
+
+/*
+ * Similar to cpu_quiet(), for which it is a helper function. Allows
+ * a group of CPUs to be quieted at one go, though all the CPUs in the
+ * group must be represented by the same leaf rcu_node structure.
+ * That structure's lock must be held upon entry, and it is released
+ * before return.
+ */
+static void
+cpu_quiet_msk(unsigned long mask, struct rcu_state *rsp, struct rcu_node *rnp,
+ unsigned long flags)
+ __releases(rnp->lock)
+{
+ /* Walk up the rcu_node hierarchy. */
+ for (;;) {
+ if (!(rnp->qsmask & mask)) {
+
+ /* Our bit has already been cleared, so done. */
+ spin_unlock_irqrestore(&rnp->lock, flags);
+ return;
+ }
+ rnp->qsmask &= ~mask;
+ if (rnp->qsmask != 0) {
+
+ /* Other bits still set at this level, so done. */
+ spin_unlock_irqrestore(&rnp->lock, flags);
+ return;
+ }
+ mask = rnp->grpmask;
+ if (rnp->parent == NULL) {
+
+ /* No more levels. Exit loop holding root lock. */
+
+ break;
+ }
+ spin_unlock_irqrestore(&rnp->lock, flags);
+ rnp = rnp->parent;
+ spin_lock_irqsave(&rnp->lock, flags);
+ }
+
+ /*
+ * Get here if we are the last CPU to pass through a quiescent
+ * state for this grace period. Clean up and let rcu_start_gp()
+ * start up the next grace period if one is needed. Note that
+ * we still hold rnp->lock, as required by rcu_start_gp(), which
+ * will release it.
+ */
+ rsp->completed = rsp->gpnum;
+ rcu_process_gp_end(rsp, rsp->rda[smp_processor_id()]);
+ rcu_start_gp(rsp, flags); /* releases rnp->lock. */
+}
+
+/*
+ * Record a quiescent state for the specified CPU, which must either be
+ * the current CPU or an offline CPU. The lastcomp argument is used to
+ * make sure we are still in the grace period of interest. We don't want
+ * to end the current grace period based on quiescent states detected in
+ * an earlier grace period!
+ */
+static void
+cpu_quiet(int cpu, struct rcu_state *rsp, struct rcu_data *rdp, long lastcomp)
+{
+ unsigned long flags;
+ unsigned long mask;
+ struct rcu_node *rnp;
+
+ rnp = rdp->mynode;
+ spin_lock_irqsave(&rnp->lock, flags);
+ if (lastcomp != ACCESS_ONCE(rsp->completed)) {
+
+ /*
+ * Someone beat us to it for this grace period, so leave.
+ * The race with GP start is resolved by the fact that we
+ * hold the leaf rcu_node lock, so that the per-CPU bits
+ * cannot yet be initialized -- so we would simply find our
+ * CPU's bit already cleared in cpu_quiet_msk() if this race
+ * occurred.
+ */
+ rdp->passed_quiesc = 0; /* try again later! */
+ spin_unlock_irqrestore(&rnp->lock, flags);
+ return;
+ }
+ mask = rdp->grpmask;
+ if ((rnp->qsmask & mask) == 0) {
+ spin_unlock_irqrestore(&rnp->lock, flags);
+ } else {
+ rdp->qs_pending = 0;
+
+ /*
+ * This GP can't end until cpu checks in, so all of our
+ * callbacks can be processed during the next GP.
+ */
+ rdp = rsp->rda[smp_processor_id()];
+ rdp->nxttail[RCU_NEXT_READY_TAIL] = rdp->nxttail[RCU_NEXT_TAIL];
+
+ cpu_quiet_msk(mask, rsp, rnp, flags); /* releases rnp->lock */
+ }
+}
+
+/*
+ * Check to see if there is a new grace period of which this CPU
+ * is not yet aware, and if so, set up local rcu_data state for it.
+ * Otherwise, see if this CPU has just passed through its first
+ * quiescent state for this grace period, and record that fact if so.
+ */
+static void
+rcu_check_quiescent_state(struct rcu_state *rsp, struct rcu_data *rdp)
+{
+ /* If there is now a new grace period, record and return. */
+ if (check_for_new_grace_period(rsp, rdp))
+ return;
+
+ /*
+ * Does this CPU still need to do its part for current grace period?
+ * If no, return and let the other CPUs do their part as well.
+ */
+ if (!rdp->qs_pending)
+ return;
+
+ /*
+ * Was there a quiescent state since the beginning of the grace
+ * period? If no, then exit and wait for the next call.
+ */
+ if (!rdp->passed_quiesc)
+ return;
+
+ /* Tell RCU we are done (but cpu_quiet() will be the judge of that). */
+ cpu_quiet(rdp->cpu, rsp, rdp, rdp->passed_quiesc_completed);
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+
+/*
+ * Remove the outgoing CPU from the bitmasks in the rcu_node hierarchy
+ * and move all callbacks from the outgoing CPU to the current one.
+ */
+static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp)
+{
+ int i;
+ unsigned long flags;
+ long lastcomp;
+ unsigned long mask;
+ struct rcu_data *rdp = rsp->rda[cpu];
+ struct rcu_data *rdp_me;
+ struct rcu_node *rnp;
+
+ /* Exclude any attempts to start a new grace period. */
+ spin_lock_irqsave(&rsp->onofflock, flags);
+
+ /* Remove the outgoing CPU from the masks in the rcu_node hierarchy. */
+ rnp = rdp->mynode;
+ mask = rdp->grpmask; /* rnp->grplo is constant. */
+ do {
+ spin_lock(&rnp->lock); /* irqs already disabled. */
+ rnp->qsmaskinit &= ~mask;
+ if (rnp->qsmaskinit != 0) {
+ spin_unlock(&rnp->lock); /* irqs already disabled. */
+ break;
+ }
+ mask = rnp->grpmask;
+ spin_unlock(&rnp->lock); /* irqs already disabled. */
+ rnp = rnp->parent;
+ } while (rnp != NULL);
+ lastcomp = rsp->completed;
+
+ spin_unlock(&rsp->onofflock); /* irqs remain disabled. */
+
+ /* Being offline is a quiescent state, so go record it. */
+ cpu_quiet(cpu, rsp, rdp, lastcomp);
+
+ /*
+ * Move callbacks from the outgoing CPU to the running CPU.
+ * Note that the outgoing CPU is now quiscent, so it is now
+ * (uncharacteristically) safe to access it rcu_data structure.
+ * Note also that we must carefully retain the order of the
+ * outgoing CPU's callbacks in order for rcu_barrier() to work
+ * correctly. Finally, note that we start all the callbacks
+ * afresh, even those that have passed through a grace period
+ * and are therefore ready to invoke. The theory is that hotplug
+ * events are rare, and that if they are frequent enough to
+ * indefinitely delay callbacks, you have far worse things to
+ * be worrying about.
+ */
+ rdp_me = rsp->rda[smp_processor_id()];
+ if (rdp->nxtlist != NULL) {
+ *rdp_me->nxttail[RCU_NEXT_TAIL] = rdp->nxtlist;
+ rdp_me->nxttail[RCU_NEXT_TAIL] = rdp->nxttail[RCU_NEXT_TAIL];
+ rdp->nxtlist = NULL;
+ for (i = 0; i < RCU_NEXT_SIZE; i++)
+ rdp->nxttail[i] = &rdp->nxtlist;
+ rdp_me->qlen += rdp->qlen;
+ rdp->qlen = 0;
+ }
+ local_irq_restore(flags);
+}
+
+/*
+ * Remove the specified CPU from the RCU hierarchy and move any pending
+ * callbacks that it might have to the current CPU. This code assumes
+ * that at least one CPU in the system will remain running at all times.
+ * Any attempt to offline -all- CPUs is likely to strand RCU callbacks.
+ */
+static void rcu_offline_cpu(int cpu)
+{
+ __rcu_offline_cpu(cpu, &rcu_state);
+ __rcu_offline_cpu(cpu, &rcu_bh_state);
+}
+
+#else /* #ifdef CONFIG_HOTPLUG_CPU */
+
+static void rcu_offline_cpu(int cpu)
+{
+}
+
+#endif /* #else #ifdef CONFIG_HOTPLUG_CPU */
+
+/*
+ * Invoke any RCU callbacks that have made it to the end of their grace
+ * period. Thottle as specified by rdp->blimit.
+ */
+static void rcu_do_batch(struct rcu_data *rdp)
+{
+ unsigned long flags;
+ struct rcu_head *next, *list, **tail;
+ int count;
+
+ /* If no callbacks are ready, just return.*/
+ if (!cpu_has_callbacks_ready_to_invoke(rdp))
+ return;
+
+ /*
+ * Extract the list of ready callbacks, disabling to prevent
+ * races with call_rcu() from interrupt handlers.
+ */
+ local_irq_save(flags);
+ list = rdp->nxtlist;
+ rdp->nxtlist = *rdp->nxttail[RCU_DONE_TAIL];
+ *rdp->nxttail[RCU_DONE_TAIL] = NULL;
+ tail = rdp->nxttail[RCU_DONE_TAIL];
+ for (count = RCU_NEXT_SIZE - 1; count >= 0; count--)
+ if (rdp->nxttail[count] == rdp->nxttail[RCU_DONE_TAIL])
+ rdp->nxttail[count] = &rdp->nxtlist;
+ local_irq_restore(flags);
+
+ /* Invoke callbacks. */
+ count = 0;
+ while (list) {
+ next = list->next;
+ prefetch(next);
+ list->func(list);
+ list = next;
+ if (++count >= rdp->blimit)
+ break;
+ }
+
+ local_irq_save(flags);
+
+ /* Update count, and requeue any remaining callbacks. */
+ rdp->qlen -= count;
+ if (list != NULL) {
+ *tail = rdp->nxtlist;
+ rdp->nxtlist = list;
+ for (count = 0; count < RCU_NEXT_SIZE; count++)
+ if (&rdp->nxtlist == rdp->nxttail[count])
+ rdp->nxttail[count] = tail;
+ else
+ break;
+ }
+
+ /* Reinstate batch limit if we have worked down the excess. */
+ if (rdp->blimit == LONG_MAX && rdp->qlen <= qlowmark)
+ rdp->blimit = blimit;
+
+ local_irq_restore(flags);
+
+ /* Re-raise the RCU softirq if there are callbacks remaining. */
+ if (cpu_has_callbacks_ready_to_invoke(rdp))
+ raise_softirq(RCU_SOFTIRQ);
+}
+
+/*
+ * Check to see if this CPU is in a non-context-switch quiescent state
+ * (user mode or idle loop for rcu, non-softirq execution for rcu_bh).
+ * Also schedule the RCU softirq handler.
+ *
+ * This function must be called with hardirqs disabled. It is normally
+ * invoked from the scheduling-clock interrupt. If rcu_pending returns
+ * false, there is no point in invoking rcu_check_callbacks().
+ */
+void rcu_check_callbacks(int cpu, int user)
+{
+ if (user ||
+ (idle_cpu(cpu) && !in_softirq() &&
+ hardirq_count() <= (1 << HARDIRQ_SHIFT))) {
+
+ /*
+ * Get here if this CPU took its interrupt from user
+ * mode or from the idle loop, and if this is not a
+ * nested interrupt. In this case, the CPU is in
+ * a quiescent state, so count it.
+ *
+ * No memory barrier is required here because both
+ * rcu_qsctr_inc() and rcu_bh_qsctr_inc() reference
+ * only CPU-local variables that other CPUs neither
+ * access nor modify, at least not while the corresponding
+ * CPU is online.
+ */
+
+ rcu_qsctr_inc(cpu);
+ rcu_bh_qsctr_inc(cpu);
+
+ } else if (!in_softirq()) {
+
+ /*
+ * Get here if this CPU did not take its interrupt from
+ * softirq, in other words, if it is not interrupting
+ * a rcu_bh read-side critical section. This is an _bh
+ * critical section, so count it.
+ */
+
+ rcu_bh_qsctr_inc(cpu);
+ }
+ raise_softirq(RCU_SOFTIRQ);
+}
+
+#ifdef CONFIG_SMP
+
+/*
+ * Scan the leaf rcu_node structures, processing dyntick state for any that
+ * have not yet encountered a quiescent state, using the function specified.
+ * Returns 1 if the current grace period ends while scanning (possibly
+ * because we made it end).
+ */
+static int rcu_process_dyntick(struct rcu_state *rsp, long lastcomp,
+ int (*f)(struct rcu_data *))
+{
+ unsigned long bit;
+ int cpu;
+ unsigned long flags;
+ unsigned long mask;
+ struct rcu_node *rnp_cur = rsp->level[NUM_RCU_LVLS - 1];
+ struct rcu_node *rnp_end = &rsp->node[NUM_RCU_NODES];
+
+ for (; rnp_cur < rnp_end; rnp_cur++) {
+ mask = 0;
+ spin_lock_irqsave(&rnp_cur->lock, flags);
+ if (rsp->completed != lastcomp) {
+ spin_unlock_irqrestore(&rnp_cur->lock, flags);
+ return 1;
+ }
+ if (rnp_cur->qsmask == 0) {
+ spin_unlock_irqrestore(&rnp_cur->lock, flags);
+ continue;
+ }
+ cpu = rnp_cur->grplo;
+ bit = 1;
+ for (; cpu <= rnp_cur->grphi; cpu++, bit <<= 1) {
+ if ((rnp_cur->qsmask & bit) != 0 && f(rsp->rda[cpu]))
+ mask |= bit;
+ }
+ if (mask != 0 && rsp->completed == lastcomp) {
+
+ /* cpu_quiet_msk() releases rnp_cur->lock. */
+ cpu_quiet_msk(mask, rsp, rnp_cur, flags);
+ continue;
+ }
+ spin_unlock_irqrestore(&rnp_cur->lock, flags);
+ }
+ return 0;
+}
+
+/*
+ * Force quiescent states on reluctant CPUs, and also detect which
+ * CPUs are in dyntick-idle mode.
+ */
+static void force_quiescent_state(struct rcu_state *rsp, int relaxed)
+{
+ unsigned long flags;
+ long lastcomp;
+ struct rcu_data *rdp = rsp->rda[smp_processor_id()];
+ struct rcu_node *rnp = rcu_get_root(rsp);
+ u8 signaled;
+
+ if (ACCESS_ONCE(rsp->completed) == ACCESS_ONCE(rsp->gpnum))
+ return; /* No grace period in progress, nothing to force. */
+ if (!spin_trylock_irqsave(&rsp->fqslock, flags)) {
+ rsp->n_force_qs_lh++; /* Inexact, can lose counts. Tough! */
+ return; /* Someone else is already on the job. */
+ }
+ if (relaxed &&
+ (long)(rsp->jiffies_force_qs - jiffies) >= 0 &&
+ (rdp->n_rcu_pending_force_qs - rdp->n_rcu_pending) >= 0)
+ goto unlock_ret; /* no emergency and done recently. */
+ rsp->n_force_qs++;
+ spin_lock(&rnp->lock);
+ lastcomp = rsp->completed;
+ signaled = rsp->signaled;
+ rsp->jiffies_force_qs = jiffies + RCU_JIFFIES_TILL_FORCE_QS;
+ rdp->n_rcu_pending_force_qs = rdp->n_rcu_pending +
+ RCU_JIFFIES_TILL_FORCE_QS;
+ if (lastcomp == rsp->gpnum) {
+ rsp->n_force_qs_ngp++;
+ spin_unlock(&rnp->lock);
+ goto unlock_ret; /* no GP in progress, time updated. */
+ }
+ spin_unlock(&rnp->lock);
+ switch (signaled) {
+ case RCU_GP_INIT:
+
+ break; /* grace period still initializing, ignore. */
+
+ case RCU_SAVE_DYNTICK:
+
+ if (RCU_SIGNAL_INIT != RCU_SAVE_DYNTICK)
+ break; /* So gcc recognizes the dead code. */
+
+ /* Record dyntick-idle state. */
+ if (rcu_process_dyntick(rsp, lastcomp,
+ dyntick_save_progress_counter))
+ goto unlock_ret;
+
+ /* Update state, record completion counter. */
+ spin_lock(&rnp->lock);
+ if (lastcomp == rsp->completed) {
+ rsp->signaled = RCU_FORCE_QS;
+ dyntick_record_completed(rsp, lastcomp);
+ }
+ spin_unlock(&rnp->lock);
+ break;
+
+ case RCU_FORCE_QS:
+
+ /* Check dyntick-idle state, send IPI to laggarts. */
+ if (rcu_process_dyntick(rsp, dyntick_recall_completed(rsp),
+ rcu_implicit_dynticks_qs))
+ goto unlock_ret;
+
+ /* Leave state in case more forcing is required. */
+
+ break;
+ }
+unlock_ret:
+ spin_unlock_irqrestore(&rsp->fqslock, flags);
+}
+
+#else /* #ifdef CONFIG_SMP */
+
+static void force_quiescent_state(struct rcu_state *rsp, int relaxed)
+{
+ set_need_resched();
+}
+
+#endif /* #else #ifdef CONFIG_SMP */
+
+/*
+ * This does the RCU processing work from softirq context for the
+ * specified rcu_state and rcu_data structures. This may be called
+ * only from the CPU to whom the rdp belongs.
+ */
+static void
+__rcu_process_callbacks(struct rcu_state *rsp, struct rcu_data *rdp)
+{
+ unsigned long flags;
+
+ /*
+ * If an RCU GP has gone long enough, go check for dyntick
+ * idle CPUs and, if needed, send resched IPIs.
+ */
+ if ((long)(ACCESS_ONCE(rsp->jiffies_force_qs) - jiffies) < 0 ||
+ (rdp->n_rcu_pending_force_qs - rdp->n_rcu_pending) < 0)
+ force_quiescent_state(rsp, 1);
+
+ /*
+ * Advance callbacks in response to end of earlier grace
+ * period that some other CPU ended.
+ */
+ rcu_process_gp_end(rsp, rdp);
+
+ /* Update RCU state based on any recent quiescent states. */
+ rcu_check_quiescent_state(rsp, rdp);
+
+ /* Does this CPU require a not-yet-started grace period? */
+ if (cpu_needs_another_gp(rsp, rdp)) {
+ spin_lock_irqsave(&rcu_get_root(rsp)->lock, flags);
+ rcu_start_gp(rsp, flags); /* releases above lock */
+ }
+
+ /* If there are callbacks ready, invoke them. */
+ rcu_do_batch(rdp);
+}
+
+/*
+ * Do softirq processing for the current CPU.
+ */
+static void rcu_process_callbacks(struct softirq_action *unused)
+{
+ /*
+ * Memory references from any prior RCU read-side critical sections
+ * executed by the interrupted code must be seen before any RCU
+ * grace-period manipulations below.
+ */
+ smp_mb(); /* See above block comment. */
+
+ __rcu_process_callbacks(&rcu_state, &__get_cpu_var(rcu_data));
+ __rcu_process_callbacks(&rcu_bh_state, &__get_cpu_var(rcu_bh_data));
+
+ /*
+ * Memory references from any later RCU read-side critical sections
+ * executed by the interrupted code must be seen after any RCU
+ * grace-period manipulations above.
+ */
+ smp_mb(); /* See above block comment. */
+}
+
+static void
+__call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu),
+ struct rcu_state *rsp)
+{
+ unsigned long flags;
+ struct rcu_data *rdp;
+
+ head->func = func;
+ head->next = NULL;
+
+ smp_mb(); /* Ensure RCU update seen before callback registry. */
+
+ /*
+ * Opportunistically note grace-period endings and beginnings.
+ * Note that we might see a beginning right after we see an
+ * end, but never vice versa, since this CPU has to pass through
+ * a quiescent state betweentimes.
+ */
+ local_irq_save(flags);
+ rdp = rsp->rda[smp_processor_id()];
+ rcu_process_gp_end(rsp, rdp);
+ check_for_new_grace_period(rsp, rdp);
+
+ /* Add the callback to our list. */
+ *rdp->nxttail[RCU_NEXT_TAIL] = head;
+ rdp->nxttail[RCU_NEXT_TAIL] = &head->next;
+
+ /* Start a new grace period if one not already started. */
+ if (ACCESS_ONCE(rsp->completed) == ACCESS_ONCE(rsp->gpnum)) {
+ unsigned long nestflag;
+ struct rcu_node *rnp_root = rcu_get_root(rsp);
+
+ spin_lock_irqsave(&rnp_root->lock, nestflag);
+ rcu_start_gp(rsp, nestflag); /* releases rnp_root->lock. */
+ }
+
+ /* Force the grace period if too many callbacks or too long waiting. */
+ if (unlikely(++rdp->qlen > qhimark)) {
+ rdp->blimit = LONG_MAX;
+ force_quiescent_state(rsp, 0);
+ } else if ((long)(ACCESS_ONCE(rsp->jiffies_force_qs) - jiffies) < 0 ||
+ (rdp->n_rcu_pending_force_qs - rdp->n_rcu_pending) < 0)
+ force_quiescent_state(rsp, 1);
+ local_irq_restore(flags);
+}
+
+/*
+ * Queue an RCU callback for invocation after a grace period.
+ */
+void call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu))
+{
+ __call_rcu(head, func, &rcu_state);
+}
+EXPORT_SYMBOL_GPL(call_rcu);
+
+/*
+ * Queue an RCU for invocation after a quicker grace period.
+ */
+void call_rcu_bh(struct rcu_head *head, void (*func)(struct rcu_head *rcu))
+{
+ __call_rcu(head, func, &rcu_bh_state);
+}
+EXPORT_SYMBOL_GPL(call_rcu_bh);
+
+/*
+ * Check to see if there is any immediate RCU-related work to be done
+ * by the current CPU, for the specified type of RCU, returning 1 if so.
+ * The checks are in order of increasing expense: checks that can be
+ * carried out against CPU-local state are performed first. However,
+ * we must check for CPU stalls first, else we might not get a chance.
+ */
+static int __rcu_pending(struct rcu_state *rsp, struct rcu_data *rdp)
+{
+ rdp->n_rcu_pending++;
+
+ /* Check for CPU stalls, if enabled. */
+ check_cpu_stall(rsp, rdp);
+
+ /* Is the RCU core waiting for a quiescent state from this CPU? */
+ if (rdp->qs_pending)
+ return 1;
+
+ /* Does this CPU have callbacks ready to invoke? */
+ if (cpu_has_callbacks_ready_to_invoke(rdp))
+ return 1;
+
+ /* Has RCU gone idle with this CPU needing another grace period? */
+ if (cpu_needs_another_gp(rsp, rdp))
+ return 1;
+
+ /* Has another RCU grace period completed? */
+ if (ACCESS_ONCE(rsp->completed) != rdp->completed) /* outside of lock */
+ return 1;
+
+ /* Has a new RCU grace period started? */
+ if (ACCESS_ONCE(rsp->gpnum) != rdp->gpnum) /* outside of lock */
+ return 1;
+
+ /* Has an RCU GP gone long enough to send resched IPIs &c? */
+ if (ACCESS_ONCE(rsp->completed) != ACCESS_ONCE(rsp->gpnum) &&
+ ((long)(ACCESS_ONCE(rsp->jiffies_force_qs) - jiffies) < 0 ||
+ (rdp->n_rcu_pending_force_qs - rdp->n_rcu_pending) < 0))
+ return 1;
+
+ /* nothing to do */
+ return 0;
+}
+
+/*
+ * Check to see if there is any immediate RCU-related work to be done
+ * by the current CPU, returning 1 if so. This function is part of the
+ * RCU implementation; it is -not- an exported member of the RCU API.
+ */
+int rcu_pending(int cpu)
+{
+ return __rcu_pending(&rcu_state, &per_cpu(rcu_data, cpu)) ||
+ __rcu_pending(&rcu_bh_state, &per_cpu(rcu_bh_data, cpu));
+}
+
+/*
+ * Check to see if any future RCU-related work will need to be done
+ * by the current CPU, even if none need be done immediately, returning
+ * 1 if so. This function is part of the RCU implementation; it is -not-
+ * an exported member of the RCU API.
+ */
+int rcu_needs_cpu(int cpu)
+{
+ /* RCU callbacks either ready or pending? */
+ return per_cpu(rcu_data, cpu).nxtlist ||
+ per_cpu(rcu_bh_data, cpu).nxtlist;
+}
+
+/*
+ * Initialize a CPU's per-CPU RCU data. We take this "scorched earth"
+ * approach so that we don't have to worry about how long the CPU has
+ * been gone, or whether it ever was online previously. We do trust the
+ * ->mynode field, as it is constant for a given struct rcu_data and
+ * initialized during early boot.
+ *
+ * Note that only one online or offline event can be happening at a given
+ * time. Note also that we can accept some slop in the rsp->completed
+ * access due to the fact that this CPU cannot possibly have any RCU
+ * callbacks in flight yet.
+ */
+static void
+rcu_init_percpu_data(int cpu, struct rcu_state *rsp)
+{
+ unsigned long flags;
+ int i;
+ long lastcomp;
+ unsigned long mask;
+ struct rcu_data *rdp = rsp->rda[cpu];
+ struct rcu_node *rnp = rcu_get_root(rsp);
+
+ /* Set up local state, ensuring consistent view of global state. */
+ spin_lock_irqsave(&rnp->lock, flags);
+ lastcomp = rsp->completed;
+ rdp->completed = lastcomp;
+ rdp->gpnum = lastcomp;
+ rdp->passed_quiesc = 0; /* We could be racing with new GP, */
+ rdp->qs_pending = 1; /* so set up to respond to current GP. */
+ rdp->beenonline = 1; /* We have now been online. */
+ rdp->passed_quiesc_completed = lastcomp - 1;
+ rdp->grpmask = 1UL << (cpu - rdp->mynode->grplo);
+ rdp->nxtlist = NULL;
+ for (i = 0; i < RCU_NEXT_SIZE; i++)
+ rdp->nxttail[i] = &rdp->nxtlist;
+ rdp->qlen = 0;
+ rdp->blimit = blimit;
+#ifdef CONFIG_NO_HZ
+ rdp->dynticks = &per_cpu(rcu_dynticks, cpu);
+#endif /* #ifdef CONFIG_NO_HZ */
+ rdp->cpu = cpu;
+ spin_unlock(&rnp->lock); /* irqs remain disabled. */
+
+ /*
+ * A new grace period might start here. If so, we won't be part
+ * of it, but that is OK, as we are currently in a quiescent state.
+ */
+
+ /* Exclude any attempts to start a new GP on large systems. */
+ spin_lock(&rsp->onofflock); /* irqs already disabled. */
+
+ /* Add CPU to rcu_node bitmasks. */
+ rnp = rdp->mynode;
+ mask = rdp->grpmask;
+ do {
+ /* Exclude any attempts to start a new GP on small systems. */
+ spin_lock(&rnp->lock); /* irqs already disabled. */
+ rnp->qsmaskinit |= mask;
+ mask = rnp->grpmask;
+ spin_unlock(&rnp->lock); /* irqs already disabled. */
+ rnp = rnp->parent;
+ } while (rnp != NULL && !(rnp->qsmaskinit & mask));
+
+ spin_unlock(&rsp->onofflock); /* irqs remain disabled. */
+
+ /*
+ * A new grace period might start here. If so, we will be part of
+ * it, and its gpnum will be greater than ours, so we will
+ * participate. It is also possible for the gpnum to have been
+ * incremented before this function was called, and the bitmasks
+ * to not be filled out until now, in which case we will also
+ * participate due to our gpnum being behind.
+ */
+
+ /* Since it is coming online, the CPU is in a quiescent state. */
+ cpu_quiet(cpu, rsp, rdp, lastcomp);
+ local_irq_restore(flags);
+}
+
+static void __cpuinit rcu_online_cpu(int cpu)
+{
+#ifdef CONFIG_NO_HZ
+ struct rcu_dynticks *rdtp = &per_cpu(rcu_dynticks, cpu);
+
+ rdtp->dynticks_nesting = 1;
+ rdtp->dynticks |= 1; /* need consecutive #s even for hotplug. */
+ rdtp->dynticks_nmi = (rdtp->dynticks_nmi + 1) & ~0x1;
+#endif /* #ifdef CONFIG_NO_HZ */
+ rcu_init_percpu_data(cpu, &rcu_state);
+ rcu_init_percpu_data(cpu, &rcu_bh_state);
+ open_softirq(RCU_SOFTIRQ, rcu_process_callbacks);
+}
+
+/*
+ * Handle CPU online/offline notifcation events.
+ */
+static int __cpuinit rcu_cpu_notify(struct notifier_block *self,
+ unsigned long action, void *hcpu)
+{
+ long cpu = (long)hcpu;
+
+ switch (action) {
+ case CPU_UP_PREPARE:
+ case CPU_UP_PREPARE_FROZEN:
+ rcu_online_cpu(cpu);
+ break;
+ case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
+ case CPU_UP_CANCELED:
+ case CPU_UP_CANCELED_FROZEN:
+ rcu_offline_cpu(cpu);
+ break;
+ default:
+ break;
+ }
+ return NOTIFY_OK;
+}
+
+/*
+ * Compute the per-level fanout, either using the exact fanout specified
+ * or balancing the tree, depending on CONFIG_RCU_FANOUT_EXACT.
+ */
+#ifdef CONFIG_RCU_FANOUT_EXACT
+static void __init rcu_init_levelspread(struct rcu_state *rsp)
+{
+ int i;
+
+ for (i = NUM_RCU_LVLS - 1; i >= 0; i--)
+ rsp->levelspread[i] = CONFIG_RCU_FANOUT;
+}
+#else /* #ifdef CONFIG_RCU_FANOUT_EXACT */
+static void __init rcu_init_levelspread(struct rcu_state *rsp)
+{
+ int ccur;
+ int cprv;
+ int i;
+
+ cprv = NR_CPUS;
+ for (i = NUM_RCU_LVLS - 1; i >= 0; i--) {
+ ccur = rsp->levelcnt[i];
+ rsp->levelspread[i] = (cprv + ccur - 1) / ccur;
+ cprv = ccur;
+ }
+}
+#endif /* #else #ifdef CONFIG_RCU_FANOUT_EXACT */
+
+/*
+ * Helper function for rcu_init() that initializes one rcu_state structure.
+ */
+static void __init rcu_init_one(struct rcu_state *rsp)
+{
+ int cpustride = 1;
+ int i;
+ int j;
+ struct rcu_node *rnp;
+
+ /* Initialize the level-tracking arrays. */
+
+ for (i = 1; i < NUM_RCU_LVLS; i++)
+ rsp->level[i] = rsp->level[i - 1] + rsp->levelcnt[i - 1];
+ rcu_init_levelspread(rsp);
+
+ /* Initialize the elements themselves, starting from the leaves. */
+
+ for (i = NUM_RCU_LVLS - 1; i >= 0; i--) {
+ cpustride *= rsp->levelspread[i];
+ rnp = rsp->level[i];
+ for (j = 0; j < rsp->levelcnt[i]; j++, rnp++) {
+ spin_lock_init(&rnp->lock);
+ rnp->qsmask = 0;
+ rnp->qsmaskinit = 0;
+ rnp->grplo = j * cpustride;
+ rnp->grphi = (j + 1) * cpustride - 1;
+ if (rnp->grphi >= NR_CPUS)
+ rnp->grphi = NR_CPUS - 1;
+ if (i == 0) {
+ rnp->grpnum = 0;
+ rnp->grpmask = 0;
+ rnp->parent = NULL;
+ } else {
+ rnp->grpnum = j % rsp->levelspread[i - 1];
+ rnp->grpmask = 1UL << rnp->grpnum;
+ rnp->parent = rsp->level[i - 1] +
+ j / rsp->levelspread[i - 1];
+ }
+ rnp->level = i;
+ }
+ }
+}
+
+/*
+ * Helper macro for __rcu_init(). To be used nowhere else!
+ * Assigns leaf node pointers into each CPU's rcu_data structure.
+ */
+#define RCU_DATA_PTR_INIT(rsp, rcu_data) \
+do { \
+ rnp = (rsp)->level[NUM_RCU_LVLS - 1]; \
+ j = 0; \
+ for_each_possible_cpu(i) { \
+ if (i > rnp[j].grphi) \
+ j++; \
+ per_cpu(rcu_data, i).mynode = &rnp[j]; \
+ (rsp)->rda[i] = &per_cpu(rcu_data, i); \
+ } \
+} while (0)
+
+static struct notifier_block __cpuinitdata rcu_nb = {
+ .notifier_call = rcu_cpu_notify,
+};
+
+void __init __rcu_init(void)
+{
+ int i; /* All used by RCU_DATA_PTR_INIT(). */
+ int j;
+ struct rcu_node *rnp;
+
+ printk(KERN_WARNING "Experimental hierarchical RCU implementation.\n");
+#ifdef CONFIG_RCU_CPU_STALL_DETECTOR
+ printk(KERN_INFO "RCU-based detection of stalled CPUs is enabled.\n");
+#endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */
+ rcu_init_one(&rcu_state);
+ RCU_DATA_PTR_INIT(&rcu_state, rcu_data);
+ rcu_init_one(&rcu_bh_state);
+ RCU_DATA_PTR_INIT(&rcu_bh_state, rcu_bh_data);
+
+ for_each_online_cpu(i)
+ rcu_cpu_notify(&rcu_nb, CPU_UP_PREPARE, (void *)(long)i);
+ /* Register notifier for non-boot CPUs */
+ register_cpu_notifier(&rcu_nb);
+ printk(KERN_WARNING "Experimental hierarchical RCU init done.\n");
+}
+
+module_param(blimit, int, 0);
+module_param(qhimark, int, 0);
+module_param(qlowmark, int, 0);
diff --git a/kernel/rcutree_trace.c b/kernel/rcutree_trace.c
new file mode 100644
index 00000000000..d6db3e83782
--- /dev/null
+++ b/kernel/rcutree_trace.c
@@ -0,0 +1,271 @@
+/*
+ * Read-Copy Update tracing for classic implementation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ * Copyright IBM Corporation, 2008
+ *
+ * Papers: http://www.rdrop.com/users/paulmck/RCU
+ *
+ * For detailed explanation of Read-Copy Update mechanism see -
+ * Documentation/RCU
+ *
+ */
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/smp.h>
+#include <linux/rcupdate.h>
+#include <linux/interrupt.h>
+#include <linux/sched.h>
+#include <asm/atomic.h>
+#include <linux/bitops.h>
+#include <linux/module.h>
+#include <linux/completion.h>
+#include <linux/moduleparam.h>
+#include <linux/percpu.h>
+#include <linux/notifier.h>
+#include <linux/cpu.h>
+#include <linux/mutex.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+
+static void print_one_rcu_data(struct seq_file *m, struct rcu_data *rdp)
+{
+ if (!rdp->beenonline)
+ return;
+ seq_printf(m, "%3d%cc=%ld g=%ld pq=%d pqc=%ld qp=%d rpfq=%ld rp=%x",
+ rdp->cpu,
+ cpu_is_offline(rdp->cpu) ? '!' : ' ',
+ rdp->completed, rdp->gpnum,
+ rdp->passed_quiesc, rdp->passed_quiesc_completed,
+ rdp->qs_pending,
+ rdp->n_rcu_pending_force_qs - rdp->n_rcu_pending,
+ (int)(rdp->n_rcu_pending & 0xffff));
+#ifdef CONFIG_NO_HZ
+ seq_printf(m, " dt=%d/%d dn=%d df=%lu",
+ rdp->dynticks->dynticks,
+ rdp->dynticks->dynticks_nesting,
+ rdp->dynticks->dynticks_nmi,
+ rdp->dynticks_fqs);
+#endif /* #ifdef CONFIG_NO_HZ */
+ seq_printf(m, " of=%lu ri=%lu", rdp->offline_fqs, rdp->resched_ipi);
+ seq_printf(m, " ql=%ld b=%ld\n", rdp->qlen, rdp->blimit);
+}
+
+#define PRINT_RCU_DATA(name, func, m) \
+ do { \
+ int _p_r_d_i; \
+ \
+ for_each_possible_cpu(_p_r_d_i) \
+ func(m, &per_cpu(name, _p_r_d_i)); \
+ } while (0)
+
+static int show_rcudata(struct seq_file *m, void *unused)
+{
+ seq_puts(m, "rcu:\n");
+ PRINT_RCU_DATA(rcu_data, print_one_rcu_data, m);
+ seq_puts(m, "rcu_bh:\n");
+ PRINT_RCU_DATA(rcu_bh_data, print_one_rcu_data, m);
+ return 0;
+}
+
+static int rcudata_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, show_rcudata, NULL);
+}
+
+static struct file_operations rcudata_fops = {
+ .owner = THIS_MODULE,
+ .open = rcudata_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static void print_one_rcu_data_csv(struct seq_file *m, struct rcu_data *rdp)
+{
+ if (!rdp->beenonline)
+ return;
+ seq_printf(m, "%d,%s,%ld,%ld,%d,%ld,%d,%ld,%ld",
+ rdp->cpu,
+ cpu_is_offline(rdp->cpu) ? "\"Y\"" : "\"N\"",
+ rdp->completed, rdp->gpnum,
+ rdp->passed_quiesc, rdp->passed_quiesc_completed,
+ rdp->qs_pending,
+ rdp->n_rcu_pending_force_qs - rdp->n_rcu_pending,
+ rdp->n_rcu_pending);
+#ifdef CONFIG_NO_HZ
+ seq_printf(m, ",%d,%d,%d,%lu",
+ rdp->dynticks->dynticks,
+ rdp->dynticks->dynticks_nesting,
+ rdp->dynticks->dynticks_nmi,
+ rdp->dynticks_fqs);
+#endif /* #ifdef CONFIG_NO_HZ */
+ seq_printf(m, ",%lu,%lu", rdp->offline_fqs, rdp->resched_ipi);
+ seq_printf(m, ",%ld,%ld\n", rdp->qlen, rdp->blimit);
+}
+
+static int show_rcudata_csv(struct seq_file *m, void *unused)
+{
+ seq_puts(m, "\"CPU\",\"Online?\",\"c\",\"g\",\"pq\",\"pqc\",\"pq\",\"rpfq\",\"rp\",");
+#ifdef CONFIG_NO_HZ
+ seq_puts(m, "\"dt\",\"dt nesting\",\"dn\",\"df\",");
+#endif /* #ifdef CONFIG_NO_HZ */
+ seq_puts(m, "\"of\",\"ri\",\"ql\",\"b\"\n");
+ seq_puts(m, "\"rcu:\"\n");
+ PRINT_RCU_DATA(rcu_data, print_one_rcu_data_csv, m);
+ seq_puts(m, "\"rcu_bh:\"\n");
+ PRINT_RCU_DATA(rcu_bh_data, print_one_rcu_data_csv, m);
+ return 0;
+}
+
+static int rcudata_csv_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, show_rcudata_csv, NULL);
+}
+
+static struct file_operations rcudata_csv_fops = {
+ .owner = THIS_MODULE,
+ .open = rcudata_csv_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static void print_one_rcu_state(struct seq_file *m, struct rcu_state *rsp)
+{
+ int level = 0;
+ struct rcu_node *rnp;
+
+ seq_printf(m, "c=%ld g=%ld s=%d jfq=%ld j=%x "
+ "nfqs=%lu/nfqsng=%lu(%lu) fqlh=%lu\n",
+ rsp->completed, rsp->gpnum, rsp->signaled,
+ (long)(rsp->jiffies_force_qs - jiffies),
+ (int)(jiffies & 0xffff),
+ rsp->n_force_qs, rsp->n_force_qs_ngp,
+ rsp->n_force_qs - rsp->n_force_qs_ngp,
+ rsp->n_force_qs_lh);
+ for (rnp = &rsp->node[0]; rnp - &rsp->node[0] < NUM_RCU_NODES; rnp++) {
+ if (rnp->level != level) {
+ seq_puts(m, "\n");
+ level = rnp->level;
+ }
+ seq_printf(m, "%lx/%lx %d:%d ^%d ",
+ rnp->qsmask, rnp->qsmaskinit,
+ rnp->grplo, rnp->grphi, rnp->grpnum);
+ }
+ seq_puts(m, "\n");
+}
+
+static int show_rcuhier(struct seq_file *m, void *unused)
+{
+ seq_puts(m, "rcu:\n");
+ print_one_rcu_state(m, &rcu_state);
+ seq_puts(m, "rcu_bh:\n");
+ print_one_rcu_state(m, &rcu_bh_state);
+ return 0;
+}
+
+static int rcuhier_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, show_rcuhier, NULL);
+}
+
+static struct file_operations rcuhier_fops = {
+ .owner = THIS_MODULE,
+ .open = rcuhier_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static int show_rcugp(struct seq_file *m, void *unused)
+{
+ seq_printf(m, "rcu: completed=%ld gpnum=%ld\n",
+ rcu_state.completed, rcu_state.gpnum);
+ seq_printf(m, "rcu_bh: completed=%ld gpnum=%ld\n",
+ rcu_bh_state.completed, rcu_bh_state.gpnum);
+ return 0;
+}
+
+static int rcugp_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, show_rcugp, NULL);
+}
+
+static struct file_operations rcugp_fops = {
+ .owner = THIS_MODULE,
+ .open = rcugp_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static struct dentry *rcudir, *datadir, *datadir_csv, *hierdir, *gpdir;
+static int __init rcuclassic_trace_init(void)
+{
+ rcudir = debugfs_create_dir("rcu", NULL);
+ if (!rcudir)
+ goto out;
+
+ datadir = debugfs_create_file("rcudata", 0444, rcudir,
+ NULL, &rcudata_fops);
+ if (!datadir)
+ goto free_out;
+
+ datadir_csv = debugfs_create_file("rcudata.csv", 0444, rcudir,
+ NULL, &rcudata_csv_fops);
+ if (!datadir_csv)
+ goto free_out;
+
+ gpdir = debugfs_create_file("rcugp", 0444, rcudir, NULL, &rcugp_fops);
+ if (!gpdir)
+ goto free_out;
+
+ hierdir = debugfs_create_file("rcuhier", 0444, rcudir,
+ NULL, &rcuhier_fops);
+ if (!hierdir)
+ goto free_out;
+ return 0;
+free_out:
+ if (datadir)
+ debugfs_remove(datadir);
+ if (datadir_csv)
+ debugfs_remove(datadir_csv);
+ if (gpdir)
+ debugfs_remove(gpdir);
+ debugfs_remove(rcudir);
+out:
+ return 1;
+}
+
+static void __exit rcuclassic_trace_cleanup(void)
+{
+ debugfs_remove(datadir);
+ debugfs_remove(datadir_csv);
+ debugfs_remove(gpdir);
+ debugfs_remove(hierdir);
+ debugfs_remove(rcudir);
+}
+
+
+module_init(rcuclassic_trace_init);
+module_exit(rcuclassic_trace_cleanup);
+
+MODULE_AUTHOR("Paul E. McKenney");
+MODULE_DESCRIPTION("Read-Copy Update tracing for hierarchical implementation");
+MODULE_LICENSE("GPL");
diff --git a/kernel/relay.c b/kernel/relay.c
index 32b0befdcb6..09ac2008f77 100644
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -1317,12 +1317,9 @@ static ssize_t relay_file_splice_read(struct file *in,
if (ret < 0)
break;
else if (!ret) {
- if (spliced)
- break;
- if (flags & SPLICE_F_NONBLOCK) {
+ if (flags & SPLICE_F_NONBLOCK)
ret = -EAGAIN;
- break;
- }
+ break;
}
*ppos += ret;
diff --git a/kernel/resource.c b/kernel/resource.c
index 4337063663e..e633106b12f 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -853,6 +853,15 @@ int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
if (PFN_DOWN(p->start) <= PFN_DOWN(addr) &&
PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1))
continue;
+ /*
+ * if a resource is "BUSY", it's not a hardware resource
+ * but a driver mapping of such a resource; we don't want
+ * to warn for those; some drivers legitimately map only
+ * partial hardware resources. (example: vesafb)
+ */
+ if (p->flags & IORESOURCE_BUSY)
+ continue;
+
printk(KERN_WARNING "resource map sanity check conflict: "
"0x%llx 0x%llx 0x%llx 0x%llx %s\n",
(unsigned long long)addr,
diff --git a/kernel/sched.c b/kernel/sched.c
index 1b8f8c3aecc..3e70963120a 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -4203,7 +4203,6 @@ void account_steal_time(struct task_struct *p, cputime_t steal)
if (p == rq->idle) {
p->stime = cputime_add(p->stime, steal);
- account_group_system_time(p, steal);
if (atomic_read(&rq->nr_iowait) > 0)
cpustat->iowait = cputime64_add(cpustat->iowait, tmp);
else
@@ -6587,7 +6586,9 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
req = list_entry(rq->migration_queue.next,
struct migration_req, list);
list_del_init(&req->list);
+ spin_unlock_irq(&rq->lock);
complete(&req->done);
+ spin_lock_irq(&rq->lock);
}
spin_unlock_irq(&rq->lock);
break;
diff --git a/kernel/sched_clock.c b/kernel/sched_clock.c
index 81787248b60..e8ab096ddfe 100644
--- a/kernel/sched_clock.c
+++ b/kernel/sched_clock.c
@@ -118,13 +118,13 @@ static u64 __update_sched_clock(struct sched_clock_data *scd, u64 now)
/*
* scd->clock = clamp(scd->tick_gtod + delta,
- * max(scd->tick_gtod, scd->clock),
- * max(scd->clock, scd->tick_gtod + TICK_NSEC));
+ * max(scd->tick_gtod, scd->clock),
+ * scd->tick_gtod + TICK_NSEC);
*/
clock = scd->tick_gtod + delta;
min_clock = wrap_max(scd->tick_gtod, scd->clock);
- max_clock = wrap_max(scd->clock, scd->tick_gtod + TICK_NSEC);
+ max_clock = scd->tick_gtod + TICK_NSEC;
clock = wrap_max(clock, min_clock);
clock = wrap_min(clock, max_clock);
diff --git a/kernel/softirq.c b/kernel/softirq.c
index e7c69a720d6..466e75ce271 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -102,20 +102,6 @@ void local_bh_disable(void)
EXPORT_SYMBOL(local_bh_disable);
-void __local_bh_enable(void)
-{
- WARN_ON_ONCE(in_irq());
-
- /*
- * softirqs should never be enabled by __local_bh_enable(),
- * it always nests inside local_bh_enable() sections:
- */
- WARN_ON_ONCE(softirq_count() == SOFTIRQ_OFFSET);
-
- sub_preempt_count(SOFTIRQ_OFFSET);
-}
-EXPORT_SYMBOL_GPL(__local_bh_enable);
-
/*
* Special-case - softirqs can safely be enabled in
* cond_resched_softirq(), or by __do_softirq(),
@@ -269,6 +255,7 @@ void irq_enter(void)
{
int cpu = smp_processor_id();
+ rcu_irq_enter();
if (idle_cpu(cpu) && !in_interrupt()) {
__irq_enter();
tick_check_idle(cpu);
@@ -295,9 +282,9 @@ void irq_exit(void)
#ifdef CONFIG_NO_HZ
/* Make sure that timer wheel updates are propagated */
- if (!in_interrupt() && idle_cpu(smp_processor_id()) && !need_resched())
- tick_nohz_stop_sched_tick(0);
rcu_irq_exit();
+ if (idle_cpu(smp_processor_id()) && !in_interrupt() && !need_resched())
+ tick_nohz_stop_sched_tick(0);
#endif
preempt_enable_no_resched();
}
diff --git a/kernel/softlockup.c b/kernel/softlockup.c
index 3953e4aed73..1ab790c67b1 100644
--- a/kernel/softlockup.c
+++ b/kernel/softlockup.c
@@ -164,7 +164,7 @@ unsigned long __read_mostly sysctl_hung_task_check_count = 1024;
/*
* Zero means infinite timeout - no checking done:
*/
-unsigned long __read_mostly sysctl_hung_task_timeout_secs = 120;
+unsigned long __read_mostly sysctl_hung_task_timeout_secs = 480;
unsigned long __read_mostly sysctl_hung_task_warnings = 10;
@@ -188,7 +188,7 @@ static void check_hung_task(struct task_struct *t, unsigned long now)
if ((long)(now - t->last_switch_timestamp) <
sysctl_hung_task_timeout_secs)
return;
- if (sysctl_hung_task_warnings < 0)
+ if (!sysctl_hung_task_warnings)
return;
sysctl_hung_task_warnings--;
diff --git a/kernel/stacktrace.c b/kernel/stacktrace.c
index 94b527ef1d1..eb212f8f8bc 100644
--- a/kernel/stacktrace.c
+++ b/kernel/stacktrace.c
@@ -6,6 +6,7 @@
* Copyright (C) 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
*/
#include <linux/sched.h>
+#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/kallsyms.h>
#include <linux/stacktrace.h>
@@ -24,3 +25,13 @@ void print_stack_trace(struct stack_trace *trace, int spaces)
}
EXPORT_SYMBOL_GPL(print_stack_trace);
+/*
+ * Architectures that do not implement save_stack_trace_tsk get this
+ * weak alias and a once-per-bootup warning (whenever this facility
+ * is utilized - for example by procfs):
+ */
+__weak void
+save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
+{
+ WARN_ONCE(1, KERN_INFO "save_stack_trace_tsk() not implemented yet.\n");
+}
diff --git a/kernel/sys.c b/kernel/sys.c
index 31deba8f7d1..5fc3a0cfb99 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -858,8 +858,8 @@ void do_sys_times(struct tms *tms)
struct task_cputime cputime;
cputime_t cutime, cstime;
- spin_lock_irq(&current->sighand->siglock);
thread_group_cputime(current, &cputime);
+ spin_lock_irq(&current->sighand->siglock);
cutime = current->signal->cutime;
cstime = current->signal->cstime;
spin_unlock_irq(&current->sighand->siglock);
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index e7acfb482a6..fa05e88aa76 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -518,6 +518,28 @@ void update_wall_time(void)
/* correct the clock when NTP error is too big */
clocksource_adjust(offset);
+ /*
+ * Since in the loop above, we accumulate any amount of time
+ * in xtime_nsec over a second into xtime.tv_sec, its possible for
+ * xtime_nsec to be fairly small after the loop. Further, if we're
+ * slightly speeding the clocksource up in clocksource_adjust(),
+ * its possible the required corrective factor to xtime_nsec could
+ * cause it to underflow.
+ *
+ * Now, we cannot simply roll the accumulated second back, since
+ * the NTP subsystem has been notified via second_overflow. So
+ * instead we push xtime_nsec forward by the amount we underflowed,
+ * and add that amount into the error.
+ *
+ * We'll correct this error next time through this function, when
+ * xtime_nsec is not as small.
+ */
+ if (unlikely((s64)clock->xtime_nsec < 0)) {
+ s64 neg = -(s64)clock->xtime_nsec;
+ clock->xtime_nsec = 0;
+ clock->error += neg << (NTP_SCALE_SHIFT - clock->shift);
+ }
+
/* store full nanoseconds into xtime after rounding it up and
* add the remainder to the error difference.
*/
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-24 15:50:40 +0000