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-rw-r--r--kernel/Makefile1
-rw-r--r--kernel/cgroup.c318
-rw-r--r--kernel/cpuset.c394
-rw-r--r--kernel/fork.c11
-rw-r--r--kernel/kexec.c18
-rw-r--r--kernel/pid.c1
-rw-r--r--kernel/res_counter.c134
-rw-r--r--kernel/sysctl.c9
8 files changed, 631 insertions, 255 deletions
diff --git a/kernel/Makefile b/kernel/Makefile
index 135a1b94344..685697c0a18 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -43,6 +43,7 @@ obj-$(CONFIG_CGROUP_DEBUG) += cgroup_debug.o
obj-$(CONFIG_CPUSETS) += cpuset.o
obj-$(CONFIG_CGROUP_NS) += ns_cgroup.o
obj-$(CONFIG_IKCONFIG) += configs.o
+obj-$(CONFIG_RESOURCE_COUNTERS) += res_counter.o
obj-$(CONFIG_STOP_MACHINE) += stop_machine.o
obj-$(CONFIG_KPROBES_SANITY_TEST) += test_kprobes.o
obj-$(CONFIG_AUDIT) += audit.o auditfilter.o
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 1a3c23936d4..4766bb65e4d 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -141,7 +141,7 @@ enum {
ROOT_NOPREFIX, /* mounted subsystems have no named prefix */
};
-inline int cgroup_is_releasable(const struct cgroup *cgrp)
+static int cgroup_is_releasable(const struct cgroup *cgrp)
{
const int bits =
(1 << CGRP_RELEASABLE) |
@@ -149,7 +149,7 @@ inline int cgroup_is_releasable(const struct cgroup *cgrp)
return (cgrp->flags & bits) == bits;
}
-inline int notify_on_release(const struct cgroup *cgrp)
+static int notify_on_release(const struct cgroup *cgrp)
{
return test_bit(CGRP_NOTIFY_ON_RELEASE, &cgrp->flags);
}
@@ -489,7 +489,7 @@ static struct css_set *find_css_set(
* Any task can increment and decrement the count field without lock.
* So in general, code holding cgroup_mutex can't rely on the count
* field not changing. However, if the count goes to zero, then only
- * attach_task() can increment it again. Because a count of zero
+ * cgroup_attach_task() can increment it again. Because a count of zero
* means that no tasks are currently attached, therefore there is no
* way a task attached to that cgroup can fork (the other way to
* increment the count). So code holding cgroup_mutex can safely
@@ -520,17 +520,17 @@ static struct css_set *find_css_set(
* The task_lock() exception
*
* The need for this exception arises from the action of
- * attach_task(), which overwrites one tasks cgroup pointer with
+ * cgroup_attach_task(), which overwrites one tasks cgroup pointer with
* another. It does so using cgroup_mutexe, however there are
* several performance critical places that need to reference
* task->cgroup without the expense of grabbing a system global
* mutex. Therefore except as noted below, when dereferencing or, as
- * in attach_task(), modifying a task'ss cgroup pointer we use
+ * in cgroup_attach_task(), modifying a task'ss cgroup pointer we use
* task_lock(), which acts on a spinlock (task->alloc_lock) already in
* the task_struct routinely used for such matters.
*
* P.S. One more locking exception. RCU is used to guard the
- * update of a tasks cgroup pointer by attach_task()
+ * update of a tasks cgroup pointer by cgroup_attach_task()
*/
/**
@@ -586,11 +586,27 @@ static struct inode *cgroup_new_inode(mode_t mode, struct super_block *sb)
return inode;
}
+/*
+ * Call subsys's pre_destroy handler.
+ * This is called before css refcnt check.
+ */
+
+static void cgroup_call_pre_destroy(struct cgroup *cgrp)
+{
+ struct cgroup_subsys *ss;
+ for_each_subsys(cgrp->root, ss)
+ if (ss->pre_destroy && cgrp->subsys[ss->subsys_id])
+ ss->pre_destroy(ss, cgrp);
+ return;
+}
+
+
static void cgroup_diput(struct dentry *dentry, struct inode *inode)
{
/* is dentry a directory ? if so, kfree() associated cgroup */
if (S_ISDIR(inode->i_mode)) {
struct cgroup *cgrp = dentry->d_fsdata;
+ struct cgroup_subsys *ss;
BUG_ON(!(cgroup_is_removed(cgrp)));
/* It's possible for external users to be holding css
* reference counts on a cgroup; css_put() needs to
@@ -599,6 +615,23 @@ static void cgroup_diput(struct dentry *dentry, struct inode *inode)
* queue the cgroup to be handled by the release
* agent */
synchronize_rcu();
+
+ mutex_lock(&cgroup_mutex);
+ /*
+ * Release the subsystem state objects.
+ */
+ for_each_subsys(cgrp->root, ss) {
+ if (cgrp->subsys[ss->subsys_id])
+ ss->destroy(ss, cgrp);
+ }
+
+ cgrp->root->number_of_cgroups--;
+ mutex_unlock(&cgroup_mutex);
+
+ /* Drop the active superblock reference that we took when we
+ * created the cgroup */
+ deactivate_super(cgrp->root->sb);
+
kfree(cgrp);
}
iput(inode);
@@ -1161,7 +1194,7 @@ static void get_first_subsys(const struct cgroup *cgrp,
* Call holding cgroup_mutex. May take task_lock of
* the task 'pid' during call.
*/
-static int attach_task(struct cgroup *cgrp, struct task_struct *tsk)
+int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk)
{
int retval = 0;
struct cgroup_subsys *ss;
@@ -1181,9 +1214,8 @@ static int attach_task(struct cgroup *cgrp, struct task_struct *tsk)
for_each_subsys(root, ss) {
if (ss->can_attach) {
retval = ss->can_attach(ss, cgrp, tsk);
- if (retval) {
+ if (retval)
return retval;
- }
}
}
@@ -1192,9 +1224,8 @@ static int attach_task(struct cgroup *cgrp, struct task_struct *tsk)
* based on its final set of cgroups
*/
newcg = find_css_set(cg, cgrp);
- if (!newcg) {
+ if (!newcg)
return -ENOMEM;
- }
task_lock(tsk);
if (tsk->flags & PF_EXITING) {
@@ -1214,9 +1245,8 @@ static int attach_task(struct cgroup *cgrp, struct task_struct *tsk)
write_unlock(&css_set_lock);
for_each_subsys(root, ss) {
- if (ss->attach) {
+ if (ss->attach)
ss->attach(ss, cgrp, oldcgrp, tsk);
- }
}
set_bit(CGRP_RELEASABLE, &oldcgrp->flags);
synchronize_rcu();
@@ -1239,7 +1269,7 @@ static int attach_task_by_pid(struct cgroup *cgrp, char *pidbuf)
if (pid) {
rcu_read_lock();
- tsk = find_task_by_pid(pid);
+ tsk = find_task_by_vpid(pid);
if (!tsk || tsk->flags & PF_EXITING) {
rcu_read_unlock();
return -ESRCH;
@@ -1257,7 +1287,7 @@ static int attach_task_by_pid(struct cgroup *cgrp, char *pidbuf)
get_task_struct(tsk);
}
- ret = attach_task(cgrp, tsk);
+ ret = cgroup_attach_task(cgrp, tsk);
put_task_struct(tsk);
return ret;
}
@@ -1329,9 +1359,14 @@ static ssize_t cgroup_common_file_write(struct cgroup *cgrp,
goto out1;
}
buffer[nbytes] = 0; /* nul-terminate */
+ strstrip(buffer); /* strip -just- trailing whitespace */
mutex_lock(&cgroup_mutex);
+ /*
+ * This was already checked for in cgroup_file_write(), but
+ * check again now we're holding cgroup_mutex.
+ */
if (cgroup_is_removed(cgrp)) {
retval = -ENODEV;
goto out2;
@@ -1349,24 +1384,9 @@ static ssize_t cgroup_common_file_write(struct cgroup *cgrp,
clear_bit(CGRP_NOTIFY_ON_RELEASE, &cgrp->flags);
break;
case FILE_RELEASE_AGENT:
- {
- struct cgroupfs_root *root = cgrp->root;
- /* Strip trailing newline */
- if (nbytes && (buffer[nbytes-1] == '\n')) {
- buffer[nbytes-1] = 0;
- }
- if (nbytes < sizeof(root->release_agent_path)) {
- /* We never write anything other than '\0'
- * into the last char of release_agent_path,
- * so it always remains a NUL-terminated
- * string */
- strncpy(root->release_agent_path, buffer, nbytes);
- root->release_agent_path[nbytes] = 0;
- } else {
- retval = -ENOSPC;
- }
+ BUILD_BUG_ON(sizeof(cgrp->root->release_agent_path) < PATH_MAX);
+ strcpy(cgrp->root->release_agent_path, buffer);
break;
- }
default:
retval = -EINVAL;
goto out2;
@@ -1387,7 +1407,7 @@ static ssize_t cgroup_file_write(struct file *file, const char __user *buf,
struct cftype *cft = __d_cft(file->f_dentry);
struct cgroup *cgrp = __d_cgrp(file->f_dentry->d_parent);
- if (!cft)
+ if (!cft || cgroup_is_removed(cgrp))
return -ENODEV;
if (cft->write)
return cft->write(cgrp, cft, file, buf, nbytes, ppos);
@@ -1457,7 +1477,7 @@ static ssize_t cgroup_file_read(struct file *file, char __user *buf,
struct cftype *cft = __d_cft(file->f_dentry);
struct cgroup *cgrp = __d_cgrp(file->f_dentry->d_parent);
- if (!cft)
+ if (!cft || cgroup_is_removed(cgrp))
return -ENODEV;
if (cft->read)
@@ -1675,6 +1695,29 @@ static void cgroup_advance_iter(struct cgroup *cgrp,
it->task = cg->tasks.next;
}
+/*
+ * To reduce the fork() overhead for systems that are not actually
+ * using their cgroups capability, we don't maintain the lists running
+ * through each css_set to its tasks until we see the list actually
+ * used - in other words after the first call to cgroup_iter_start().
+ *
+ * The tasklist_lock is not held here, as do_each_thread() and
+ * while_each_thread() are protected by RCU.
+ */
+void cgroup_enable_task_cg_lists(void)
+{
+ struct task_struct *p, *g;
+ write_lock(&css_set_lock);
+ use_task_css_set_links = 1;
+ do_each_thread(g, p) {
+ task_lock(p);
+ if (list_empty(&p->cg_list))
+ list_add(&p->cg_list, &p->cgroups->tasks);
+ task_unlock(p);
+ } while_each_thread(g, p);
+ write_unlock(&css_set_lock);
+}
+
void cgroup_iter_start(struct cgroup *cgrp, struct cgroup_iter *it)
{
/*
@@ -1682,18 +1725,9 @@ void cgroup_iter_start(struct cgroup *cgrp, struct cgroup_iter *it)
* we need to enable the list linking each css_set to its
* tasks, and fix up all existing tasks.
*/
- if (!use_task_css_set_links) {
- struct task_struct *p, *g;
- write_lock(&css_set_lock);
- use_task_css_set_links = 1;
- do_each_thread(g, p) {
- task_lock(p);
- if (list_empty(&p->cg_list))
- list_add(&p->cg_list, &p->cgroups->tasks);
- task_unlock(p);
- } while_each_thread(g, p);
- write_unlock(&css_set_lock);
- }
+ if (!use_task_css_set_links)
+ cgroup_enable_task_cg_lists();
+
read_lock(&css_set_lock);
it->cg_link = &cgrp->css_sets;
cgroup_advance_iter(cgrp, it);
@@ -1726,6 +1760,166 @@ void cgroup_iter_end(struct cgroup *cgrp, struct cgroup_iter *it)
read_unlock(&css_set_lock);
}
+static inline int started_after_time(struct task_struct *t1,
+ struct timespec *time,
+ struct task_struct *t2)
+{
+ int start_diff = timespec_compare(&t1->start_time, time);
+ if (start_diff > 0) {
+ return 1;
+ } else if (start_diff < 0) {
+ return 0;
+ } else {
+ /*
+ * Arbitrarily, if two processes started at the same
+ * time, we'll say that the lower pointer value
+ * started first. Note that t2 may have exited by now
+ * so this may not be a valid pointer any longer, but
+ * that's fine - it still serves to distinguish
+ * between two tasks started (effectively) simultaneously.
+ */
+ return t1 > t2;
+ }
+}
+
+/*
+ * This function is a callback from heap_insert() and is used to order
+ * the heap.
+ * In this case we order the heap in descending task start time.
+ */
+static inline int started_after(void *p1, void *p2)
+{
+ struct task_struct *t1 = p1;
+ struct task_struct *t2 = p2;
+ return started_after_time(t1, &t2->start_time, t2);
+}
+
+/**
+ * cgroup_scan_tasks - iterate though all the tasks in a cgroup
+ * @scan: struct cgroup_scanner containing arguments for the scan
+ *
+ * Arguments include pointers to callback functions test_task() and
+ * process_task().
+ * Iterate through all the tasks in a cgroup, calling test_task() for each,
+ * and if it returns true, call process_task() for it also.
+ * The test_task pointer may be NULL, meaning always true (select all tasks).
+ * Effectively duplicates cgroup_iter_{start,next,end}()
+ * but does not lock css_set_lock for the call to process_task().
+ * The struct cgroup_scanner may be embedded in any structure of the caller's
+ * creation.
+ * It is guaranteed that process_task() will act on every task that
+ * is a member of the cgroup for the duration of this call. This
+ * function may or may not call process_task() for tasks that exit
+ * or move to a different cgroup during the call, or are forked or
+ * move into the cgroup during the call.
+ *
+ * Note that test_task() may be called with locks held, and may in some
+ * situations be called multiple times for the same task, so it should
+ * be cheap.
+ * If the heap pointer in the struct cgroup_scanner is non-NULL, a heap has been
+ * pre-allocated and will be used for heap operations (and its "gt" member will
+ * be overwritten), else a temporary heap will be used (allocation of which
+ * may cause this function to fail).
+ */
+int cgroup_scan_tasks(struct cgroup_scanner *scan)
+{
+ int retval, i;
+ struct cgroup_iter it;
+ struct task_struct *p, *dropped;
+ /* Never dereference latest_task, since it's not refcounted */
+ struct task_struct *latest_task = NULL;
+ struct ptr_heap tmp_heap;
+ struct ptr_heap *heap;
+ struct timespec latest_time = { 0, 0 };
+
+ if (scan->heap) {
+ /* The caller supplied our heap and pre-allocated its memory */
+ heap = scan->heap;
+ heap->gt = &started_after;
+ } else {
+ /* We need to allocate our own heap memory */
+ heap = &tmp_heap;
+ retval = heap_init(heap, PAGE_SIZE, GFP_KERNEL, &started_after);
+ if (retval)
+ /* cannot allocate the heap */
+ return retval;
+ }
+
+ again:
+ /*
+ * Scan tasks in the cgroup, using the scanner's "test_task" callback
+ * to determine which are of interest, and using the scanner's
+ * "process_task" callback to process any of them that need an update.
+ * Since we don't want to hold any locks during the task updates,
+ * gather tasks to be processed in a heap structure.
+ * The heap is sorted by descending task start time.
+ * If the statically-sized heap fills up, we overflow tasks that
+ * started later, and in future iterations only consider tasks that
+ * started after the latest task in the previous pass. This
+ * guarantees forward progress and that we don't miss any tasks.
+ */
+ heap->size = 0;
+ cgroup_iter_start(scan->cg, &it);
+ while ((p = cgroup_iter_next(scan->cg, &it))) {
+ /*
+ * Only affect tasks that qualify per the caller's callback,
+ * if he provided one
+ */
+ if (scan->test_task && !scan->test_task(p, scan))
+ continue;
+ /*
+ * Only process tasks that started after the last task
+ * we processed
+ */
+ if (!started_after_time(p, &latest_time, latest_task))
+ continue;
+ dropped = heap_insert(heap, p);
+ if (dropped == NULL) {
+ /*
+ * The new task was inserted; the heap wasn't
+ * previously full
+ */
+ get_task_struct(p);
+ } else if (dropped != p) {
+ /*
+ * The new task was inserted, and pushed out a
+ * different task
+ */
+ get_task_struct(p);
+ put_task_struct(dropped);
+ }
+ /*
+ * Else the new task was newer than anything already in
+ * the heap and wasn't inserted
+ */
+ }
+ cgroup_iter_end(scan->cg, &it);
+
+ if (heap->size) {
+ for (i = 0; i < heap->size; i++) {
+ struct task_struct *p = heap->ptrs[i];
+ if (i == 0) {
+ latest_time = p->start_time;
+ latest_task = p;
+ }
+ /* Process the task per the caller's callback */
+ scan->process_task(p, scan);
+ put_task_struct(p);
+ }
+ /*
+ * If we had to process any tasks at all, scan again
+ * in case some of them were in the middle of forking
+ * children that didn't get processed.
+ * Not the most efficient way to do it, but it avoids
+ * having to take callback_mutex in the fork path
+ */
+ goto again;
+ }
+ if (heap == &tmp_heap)
+ heap_free(&tmp_heap);
+ return 0;
+}
+
/*
* Stuff for reading the 'tasks' file.
*
@@ -1761,7 +1955,7 @@ static int pid_array_load(pid_t *pidarray, int npids, struct cgroup *cgrp)
while ((tsk = cgroup_iter_next(cgrp, &it))) {
if (unlikely(n == npids))
break;
- pidarray[n++] = task_pid_nr(tsk);
+ pidarray[n++] = task_pid_vnr(tsk);
}
cgroup_iter_end(cgrp, &it);
return n;
@@ -2126,9 +2320,8 @@ static inline int cgroup_has_css_refs(struct cgroup *cgrp)
* matter, since it can only happen if the cgroup
* has been deleted and hence no longer needs the
* release agent to be called anyway. */
- if (css && atomic_read(&css->refcnt)) {
+ if (css && atomic_read(&css->refcnt))
return 1;
- }
}
return 0;
}
@@ -2138,7 +2331,6 @@ static int cgroup_rmdir(struct inode *unused_dir, struct dentry *dentry)
struct cgroup *cgrp = dentry->d_fsdata;
struct dentry *d;
struct cgroup *parent;
- struct cgroup_subsys *ss;
struct super_block *sb;
struct cgroupfs_root *root;
@@ -2157,17 +2349,19 @@ static int cgroup_rmdir(struct inode *unused_dir, struct dentry *dentry)
parent = cgrp->parent;
root = cgrp->root;
sb = root->sb;
+ /*
+ * Call pre_destroy handlers of subsys
+ */
+ cgroup_call_pre_destroy(cgrp);
+ /*
+ * Notify subsyses that rmdir() request comes.
+ */
if (cgroup_has_css_refs(cgrp)) {
mutex_unlock(&cgroup_mutex);
return -EBUSY;
}
- for_each_subsys(root, ss) {
- if (cgrp->subsys[ss->subsys_id])
- ss->destroy(ss, cgrp);
- }
-
spin_lock(&release_list_lock);
set_bit(CGRP_REMOVED, &cgrp->flags);
if (!list_empty(&cgrp->release_list))
@@ -2182,15 +2376,11 @@ static int cgroup_rmdir(struct inode *unused_dir, struct dentry *dentry)
cgroup_d_remove_dir(d);
dput(d);
- root->number_of_cgroups--;
set_bit(CGRP_RELEASABLE, &parent->flags);
check_for_release(parent);
mutex_unlock(&cgroup_mutex);
- /* Drop the active superblock reference that we took when we
- * created the cgroup */
- deactivate_super(sb);
return 0;
}
@@ -2324,7 +2514,7 @@ out:
* - Used for /proc/<pid>/cgroup.
* - No need to task_lock(tsk) on this tsk->cgroup reference, as it
* doesn't really matter if tsk->cgroup changes after we read it,
- * and we take cgroup_mutex, keeping attach_task() from changing it
+ * and we take cgroup_mutex, keeping cgroup_attach_task() from changing it
* anyway. No need to check that tsk->cgroup != NULL, thanks to
* the_top_cgroup_hack in cgroup_exit(), which sets an exiting tasks
* cgroup to top_cgroup.
@@ -2435,7 +2625,7 @@ static struct file_operations proc_cgroupstats_operations = {
* A pointer to the shared css_set was automatically copied in
* fork.c by dup_task_struct(). However, we ignore that copy, since
* it was not made under the protection of RCU or cgroup_mutex, so
- * might no longer be a valid cgroup pointer. attach_task() might
+ * might no longer be a valid cgroup pointer. cgroup_attach_task() might
* have already changed current->cgroups, allowing the previously
* referenced cgroup group to be removed and freed.
*
@@ -2514,8 +2704,8 @@ void cgroup_post_fork(struct task_struct *child)
* attach us to a different cgroup, decrementing the count on
* the first cgroup that we never incremented. But in this case,
* top_cgroup isn't going away, and either task has PF_EXITING set,
- * which wards off any attach_task() attempts, or task is a failed
- * fork, never visible to attach_task.
+ * which wards off any cgroup_attach_task() attempts, or task is a failed
+ * fork, never visible to cgroup_attach_task.
*
*/
void cgroup_exit(struct task_struct *tsk, int run_callbacks)
@@ -2655,7 +2845,7 @@ int cgroup_clone(struct task_struct *tsk, struct cgroup_subsys *subsys)
}
/* All seems fine. Finish by moving the task into the new cgroup */
- ret = attach_task(child, tsk);
+ ret = cgroup_attach_task(child, tsk);
mutex_unlock(&cgroup_mutex);
out_release:
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index cfaf6419d81..67b2bfe2781 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -38,7 +38,6 @@
#include <linux/mount.h>
#include <linux/namei.h>
#include <linux/pagemap.h>
-#include <linux/prio_heap.h>
#include <linux/proc_fs.h>
#include <linux/rcupdate.h>
#include <linux/sched.h>
@@ -56,6 +55,8 @@
#include <asm/atomic.h>
#include <linux/mutex.h>
#include <linux/kfifo.h>
+#include <linux/workqueue.h>
+#include <linux/cgroup.h>
/*
* Tracks how many cpusets are currently defined in system.
@@ -64,7 +65,7 @@
*/
int number_of_cpusets __read_mostly;
-/* Retrieve the cpuset from a cgroup */
+/* Forward declare cgroup structures */
struct cgroup_subsys cpuset_subsys;
struct cpuset;
@@ -96,6 +97,9 @@ struct cpuset {
/* partition number for rebuild_sched_domains() */
int pn;
+
+ /* used for walking a cpuset heirarchy */
+ struct list_head stack_list;
};
/* Retrieve the cpuset for a cgroup */
@@ -111,7 +115,10 @@ static inline struct cpuset *task_cs(struct task_struct *task)
return container_of(task_subsys_state(task, cpuset_subsys_id),
struct cpuset, css);
}
-
+struct cpuset_hotplug_scanner {
+ struct cgroup_scanner scan;
+ struct cgroup *to;
+};
/* bits in struct cpuset flags field */
typedef enum {
@@ -160,17 +167,17 @@ static inline int is_spread_slab(const struct cpuset *cs)
* number, and avoid having to lock and reload mems_allowed unless
* the cpuset they're using changes generation.
*
- * A single, global generation is needed because attach_task() could
+ * A single, global generation is needed because cpuset_attach_task() could
* reattach a task to a different cpuset, which must not have its
* generation numbers aliased with those of that tasks previous cpuset.
*
* Generations are needed for mems_allowed because one task cannot
- * modify anothers memory placement. So we must enable every task,
+ * modify another's memory placement. So we must enable every task,
* on every visit to __alloc_pages(), to efficiently check whether
* its current->cpuset->mems_allowed has changed, requiring an update
* of its current->mems_allowed.
*
- * Since cpuset_mems_generation is guarded by manage_mutex,
+ * Since writes to cpuset_mems_generation are guarded by the cgroup lock
* there is no need to mark it atomic.
*/
static int cpuset_mems_generation;
@@ -182,17 +189,20 @@ static struct cpuset top_cpuset = {
};
/*
- * We have two global cpuset mutexes below. They can nest.
- * It is ok to first take manage_mutex, then nest callback_mutex. We also
- * require taking task_lock() when dereferencing a tasks cpuset pointer.
- * See "The task_lock() exception", at the end of this comment.
+ * There are two global mutexes guarding cpuset structures. The first
+ * is the main control groups cgroup_mutex, accessed via
+ * cgroup_lock()/cgroup_unlock(). The second is the cpuset-specific
+ * callback_mutex, below. They can nest. It is ok to first take
+ * cgroup_mutex, then nest callback_mutex. We also require taking
+ * task_lock() when dereferencing a task's cpuset pointer. See "The
+ * task_lock() exception", at the end of this comment.
*
* A task must hold both mutexes to modify cpusets. If a task
- * holds manage_mutex, then it blocks others wanting that mutex,
+ * holds cgroup_mutex, then it blocks others wanting that mutex,
* ensuring that it is the only task able to also acquire callback_mutex
* and be able to modify cpusets. It can perform various checks on
* the cpuset structure first, knowing nothing will change. It can
- * also allocate memory while just holding manage_mutex. While it is
+ * also allocate memory while just holding cgroup_mutex. While it is
* performing these checks, various callback routines can briefly
* acquire callback_mutex to query cpusets. Once it is ready to make
* the changes, it takes callback_mutex, blocking everyone else.
@@ -208,60 +218,16 @@ static struct cpuset top_cpuset = {
* The task_struct fields mems_allowed and mems_generation may only
* be accessed in the context of that task, so require no locks.
*
- * Any task can increment and decrement the count field without lock.
- * So in general, code holding manage_mutex or callback_mutex can't rely
- * on the count field not changing. However, if the count goes to
- * zero, then only attach_task(), which holds both mutexes, can
- * increment it again. Because a count of zero means that no tasks
- * are currently attached, therefore there is no way a task attached
- * to that cpuset can fork (the other way to increment the count).
- * So code holding manage_mutex or callback_mutex can safely assume that
- * if the count is zero, it will stay zero. Similarly, if a task
- * holds manage_mutex or callback_mutex on a cpuset with zero count, it
- * knows that the cpuset won't be removed, as cpuset_rmdir() needs
- * both of those mutexes.
- *
* The cpuset_common_file_write handler for operations that modify
- * the cpuset hierarchy holds manage_mutex across the entire operation,
+ * the cpuset hierarchy holds cgroup_mutex across the entire operation,
* single threading all such cpuset modifications across the system.
*
* The cpuset_common_file_read() handlers only hold callback_mutex across
* small pieces of code, such as when reading out possibly multi-word
* cpumasks and nodemasks.
*
- * The fork and exit callbacks cpuset_fork() and cpuset_exit(), don't
- * (usually) take either mutex. These are the two most performance
- * critical pieces of code here. The exception occurs on cpuset_exit(),
- * when a task in a notify_on_release cpuset exits. Then manage_mutex
- * is taken, and if the cpuset count is zero, a usermode call made
- * to /sbin/cpuset_release_agent with the name of the cpuset (path
- * relative to the root of cpuset file system) as the argument.
- *
- * A cpuset can only be deleted if both its 'count' of using tasks
- * is zero, and its list of 'children' cpusets is empty. Since all
- * tasks in the system use _some_ cpuset, and since there is always at
- * least one task in the system (init), therefore, top_cpuset
- * always has either children cpusets and/or using tasks. So we don't
- * need a special hack to ensure that top_cpuset cannot be deleted.
- *
- * The above "Tale of Two Semaphores" would be complete, but for:
- *
- * The task_lock() exception
- *
- * The need for this exception arises from the action of attach_task(),
- * which overwrites one tasks cpuset pointer with another. It does
- * so using both mutexes, however there are several performance
- * critical places that need to reference task->cpuset without the
- * expense of grabbing a system global mutex. Therefore except as
- * noted below, when dereferencing or, as in attach_task(), modifying
- * a tasks cpuset pointer we use task_lock(), which acts on a spinlock
- * (task->alloc_lock) already in the task_struct routinely used for
- * such matters.
- *
- * P.S. One more locking exception. RCU is used to guard the
- * update of a tasks cpuset pointer by attach_task() and the
- * access of task->cpuset->mems_generation via that pointer in
- * the routine cpuset_update_task_memory_state().
+ * Accessing a task's cpuset should be done in accordance with the
+ * guidelines for accessing subsystem state in kernel/cgroup.c
*/
static DEFINE_MUTEX(callback_mutex);
@@ -354,15 +320,14 @@ static void guarantee_online_mems(const struct cpuset *cs, nodemask_t *pmask)
* Do not call this routine if in_interrupt().
*
* Call without callback_mutex or task_lock() held. May be
- * called with or without manage_mutex held. Thanks in part to
- * 'the_top_cpuset_hack', the tasks cpuset pointer will never
+ * called with or without cgroup_mutex held. Thanks in part to
+ * 'the_top_cpuset_hack', the task's cpuset pointer will never
* be NULL. This routine also might acquire callback_mutex and
* current->mm->mmap_sem during call.
*
* Reading current->cpuset->mems_generation doesn't need task_lock
* to guard the current->cpuset derefence, because it is guarded
- * from concurrent freeing of current->cpuset by attach_task(),
- * using RCU.
+ * from concurrent freeing of current->cpuset using RCU.
*
* The rcu_dereference() is technically probably not needed,
* as I don't actually mind if I see a new cpuset pointer but
@@ -424,7 +389,7 @@ void cpuset_update_task_memory_state(void)
*
* One cpuset is a subset of another if all its allowed CPUs and
* Memory Nodes are a subset of the other, and its exclusive flags
- * are only set if the other's are set. Call holding manage_mutex.
+ * are only set if the other's are set. Call holding cgroup_mutex.
*/
static int is_cpuset_subset(const struct cpuset *p, const struct cpuset *q)
@@ -442,7 +407,7 @@ static int is_cpuset_subset(const struct cpuset *p, const struct cpuset *q)
* If we replaced the flag and mask values of the current cpuset
* (cur) with those values in the trial cpuset (trial), would
* our various subset and exclusive rules still be valid? Presumes
- * manage_mutex held.
+ * cgroup_mutex held.
*
* 'cur' is the address of an actual, in-use cpuset. Operations
* such as list traversal that depend on the actual address of the
@@ -476,7 +441,10 @@ static int validate_change(const struct cpuset *cur, const struct cpuset *trial)
if (!is_cpuset_subset(trial, par))
return -EACCES;
- /* If either I or some sibling (!= me) is exclusive, we can't overlap */
+ /*
+ * If either I or some sibling (!= me) is exclusive, we can't
+ * overlap
+ */
list_for_each_entry(cont, &par->css.cgroup->children, sibling) {
c = cgroup_cs(cont);
if ((is_cpu_exclusive(trial) || is_cpu_exclusive(c)) &&
@@ -732,22 +700,50 @@ static inline int started_after(void *p1, void *p2)
return started_after_time(t1, &t2->start_time, t2);
}
-/*
- * Call with manage_mutex held. May take callback_mutex during call.
+/**
+ * cpuset_test_cpumask - test a task's cpus_allowed versus its cpuset's
+ * @tsk: task to test
+ * @scan: struct cgroup_scanner contained in its struct cpuset_hotplug_scanner
+ *
+ * Call with cgroup_mutex held. May take callback_mutex during call.
+ * Called for each task in a cgroup by cgroup_scan_tasks().
+ * Return nonzero if this tasks's cpus_allowed mask should be changed (in other
+ * words, if its mask is not equal to its cpuset's mask).
+ */
+int cpuset_test_cpumask(struct task_struct *tsk, struct cgroup_scanner *scan)
+{
+ return !cpus_equal(tsk->cpus_allowed,
+ (cgroup_cs(scan->cg))->cpus_allowed);
+}
+
+/**
+ * cpuset_change_cpumask - make a task's cpus_allowed the same as its cpuset's
+ * @tsk: task to test
+ * @scan: struct cgroup_scanner containing the cgroup of the task
+ *
+ * Called by cgroup_scan_tasks() for each task in a cgroup whose
+ * cpus_allowed mask needs to be changed.
+ *
+ * We don't need to re-check for the cgroup/cpuset membership, since we're
+ * holding cgroup_lock() at this point.
*/
+void cpuset_change_cpumask(struct task_struct *tsk, struct cgroup_scanner *scan)
+{
+ set_cpus_allowed(tsk, (cgroup_cs(scan->cg))->cpus_allowed);
+}
+/**
+ * update_cpumask - update the cpus_allowed mask of a cpuset and all tasks in it
+ * @cs: the cpuset to consider
+ * @buf: buffer of cpu numbers written to this cpuset
+ */
static int update_cpumask(struct cpuset *cs, char *buf)
{
struct cpuset trialcs;
- int retval, i;
- int is_load_balanced;
- struct cgroup_iter it;
- struct cgroup *cgrp = cs->css.cgroup;
- struct task_struct *p, *dropped;
- /* Never dereference latest_task, since it's not refcounted */
- struct task_struct *latest_task = NULL;
+ struct cgroup_scanner scan;
struct ptr_heap heap;
- struct timespec latest_time = { 0, 0 };
+ int retval;
+ int is_load_balanced;
/* top_cpuset.cpus_allowed tracks cpu_online_map; it's read-only */
if (cs == &top_cpuset)
@@ -756,7 +752,7 @@ static int update_cpumask(struct cpuset *cs, char *buf)
trialcs = *cs;
/*
- * An empty cpus_allowed is ok iff there are no tasks in the cpuset.
+ * An empty cpus_allowed is ok only if the cpuset has no tasks.
* Since cpulist_parse() fails on an empty mask, we special case
* that parsing. The validate_change() call ensures that cpusets
* with tasks have cpus.
@@ -777,6 +773,7 @@ static int update_cpumask(struct cpuset *cs, char *buf)
/* Nothing to do if the cpus didn't change */
if (cpus_equal(cs->cpus_allowed, trialcs.cpus_allowed))
return 0;
+
retval = heap_init(&heap, PAGE_SIZE, GFP_KERNEL, &started_after);
if (retval)
return retval;
@@ -787,62 +784,19 @@ static int update_cpumask(struct cpuset *cs, char *buf)
cs->cpus_allowed = trialcs.cpus_allowed;
mutex_unlock(&callback_mutex);
- again:
/*
* Scan tasks in the cpuset, and update the cpumasks of any
- * that need an update. Since we can't call set_cpus_allowed()
- * while holding tasklist_lock, gather tasks to be processed
- * in a heap structure. If the statically-sized heap fills up,
- * overflow tasks that started later, and in future iterations
- * only consider tasks that started after the latest task in
- * the previous pass. This guarantees forward progress and
- * that we don't miss any tasks
+ * that need an update.
*/
- heap.size = 0;
- cgroup_iter_start(cgrp, &it);
- while ((p = cgroup_iter_next(cgrp, &it))) {
- /* Only affect tasks that don't have the right cpus_allowed */
- if (cpus_equal(p->cpus_allowed, cs->cpus_allowed))
- continue;
- /*
- * Only process tasks that started after the last task
- * we processed
- */
- if (!started_after_time(p, &latest_time, latest_task))
- continue;
- dropped = heap_insert(&heap, p);
- if (dropped == NULL) {
- get_task_struct(p);
- } else if (dropped != p) {
- get_task_struct(p);
- put_task_struct(dropped);
- }
- }
- cgroup_iter_end(cgrp, &it);
- if (heap.size) {
- for (i = 0; i < heap.size; i++) {
- struct task_struct *p = heap.ptrs[i];
- if (i == 0) {
- latest_time = p->start_time;
- latest_task = p;
- }
- set_cpus_allowed(p, cs->cpus_allowed);
- put_task_struct(p);
- }
- /*
- * If we had to process any tasks at all, scan again
- * in case some of them were in the middle of forking
- * children that didn't notice the new cpumask
- * restriction. Not the most efficient way to do it,
- * but it avoids having to take callback_mutex in the
- * fork path
- */
- goto again;
- }
+ scan.cg = cs->css.cgroup;
+ scan.test_task = cpuset_test_cpumask;
+ scan.process_task = cpuset_change_cpumask;
+ scan.heap = &heap;
+ cgroup_scan_tasks(&scan);
heap_free(&heap);
+
if (is_load_balanced)
rebuild_sched_domains();
-
return 0;
}
@@ -854,11 +808,11 @@ static int update_cpumask(struct cpuset *cs, char *buf)
* Temporarilly set tasks mems_allowed to target nodes of migration,
* so that the migration code can allocate pages on these nodes.
*
- * Call holding manage_mutex, so our current->cpuset won't change
- * during this call, as manage_mutex holds off any attach_task()
+ * Call holding cgroup_mutex, so current's cpuset won't change
+ * during this call, as manage_mutex holds off any cpuset_attach()
* calls. Therefore we don't need to take task_lock around the
* call to guarantee_online_mems(), as we know no one is changing
- * our tasks cpuset.
+ * our task's cpuset.
*
* Hold callback_mutex around the two modifications of our tasks
* mems_allowed to synchronize with cpuset_mems_allowed().
@@ -903,7 +857,7 @@ static void cpuset_migrate_mm(struct mm_struct *mm, const nodemask_t *from,
* the cpuset is marked 'memory_migrate', migrate the tasks
* pages to the new memory.
*
- * Call with manage_mutex held. May take callback_mutex during call.
+ * Call with cgroup_mutex held. May take callback_mutex during call.
* Will take tasklist_lock, scan tasklist for tasks in cpuset cs,
* lock each such tasks mm->mmap_sem, scan its vma's and rebind
* their mempolicies to the cpusets new mems_allowed.
@@ -1016,7 +970,7 @@ static int update_nodemask(struct cpuset *cs, char *buf)
* tasklist_lock. Forks can happen again now - the mpol_copy()
* cpuset_being_rebound check will catch such forks, and rebind
* their vma mempolicies too. Because we still hold the global
- * cpuset manage_mutex, we know that no other rebind effort will
+ * cgroup_mutex, we know that no other rebind effort will
* be contending for the global variable cpuset_being_rebound.
* It's ok if we rebind the same mm twice; mpol_rebind_mm()
* is idempotent. Also migrate pages in each mm to new nodes.
@@ -1031,7 +985,7 @@ static int update_nodemask(struct cpuset *cs, char *buf)
mmput(mm);
}
- /* We're done rebinding vma's to this cpusets new mems_allowed. */
+ /* We're done rebinding vmas to this cpuset's new mems_allowed. */
kfree(mmarray);
cpuset_being_rebound = NULL;
retval = 0;
@@ -1045,7 +999,7 @@ int current_cpuset_is_being_rebound(void)
}
/*
- * Call with manage_mutex held.
+ * Call with cgroup_mutex held.
*/
static int update_memory_pressure_enabled(struct cpuset *cs, char *buf)
@@ -1066,7 +1020,7 @@ static int update_memory_pressure_enabled(struct cpuset *cs, char *buf)
* cs: the cpuset to update
* buf: the buffer where we read the 0 or 1
*
- * Call with manage_mutex held.
+ * Call with cgroup_mutex held.
*/
static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs, char *buf)
@@ -1200,6 +1154,7 @@ static int fmeter_getrate(struct fmeter *fmp)
return val;
}
+/* Called by cgroups to determine if a cpuset is usable; cgroup_mutex held */
static int cpuset_can_attach(struct cgroup_subsys *ss,
struct cgroup *cont, struct task_struct *tsk)
{
@@ -1547,7 +1502,8 @@ static int cpuset_populate(struct cgroup_subsys *ss, struct cgroup *cont)
* If this becomes a problem for some users who wish to
* allow that scenario, then cpuset_post_clone() could be
* changed to grant parent->cpus_allowed-sibling_cpus_exclusive
- * (and likewise for mems) to the new cgroup.
+ * (and likewise for mems) to the new cgroup. Called with cgroup_mutex
+ * held.
*/
static void cpuset_post_clone(struct cgroup_subsys *ss,
struct cgroup *cgroup)
@@ -1571,11 +1527,8 @@ static void cpuset_post_clone(struct cgroup_subsys *ss,
/*
* cpuset_create - create a cpuset
- * parent: cpuset that will be parent of the new cpuset.
- * name: name of the new cpuset. Will be strcpy'ed.
- * mode: mode to set on new inode
- *
- * Must be called with the mutex on the parent inode held
+ * ss: cpuset cgroup subsystem
+ * cont: control group that the new cpuset will be part of
*/
static struct cgroup_subsys_state *cpuset_create(
@@ -1687,53 +1640,140 @@ int __init cpuset_init(void)
return 0;
}
+/**
+ * cpuset_do_move_task - move a given task to another cpuset
+ * @tsk: pointer to task_struct the task to move
+ * @scan: struct cgroup_scanner contained in its struct cpuset_hotplug_scanner
+ *
+ * Called by cgroup_scan_tasks() for each task in a cgroup.
+ * Return nonzero to stop the walk through the tasks.
+ */
+void cpuset_do_move_task(struct task_struct *tsk, struct cgroup_scanner *scan)
+{
+ struct cpuset_hotplug_scanner *chsp;
+
+ chsp = container_of(scan, struct cpuset_hotplug_scanner, scan);
+ cgroup_attach_task(chsp->to, tsk);
+}
+
+/**
+ * move_member_tasks_to_cpuset - move tasks from one cpuset to another
+ * @from: cpuset in which the tasks currently reside
+ * @to: cpuset to which the tasks will be moved
+ *
+ * Called with cgroup_mutex held
+ * callback_mutex must not be held, as cpuset_attach() will take it.
+ *
+ * The cgroup_scan_tasks() function will scan all the tasks in a cgroup,
+ * calling callback functions for each.
+ */
+static void move_member_tasks_to_cpuset(struct cpuset *from, struct cpuset *to)
+{
+ struct cpuset_hotplug_scanner scan;
+
+ scan.scan.cg = from->css.cgroup;
+ scan.scan.test_task = NULL; /* select all tasks in cgroup */
+ scan.scan.process_task = cpuset_do_move_task;
+ scan.scan.heap = NULL;
+ scan.to = to->css.cgroup;
+
+ if (cgroup_scan_tasks((struct cgroup_scanner *)&scan))
+ printk(KERN_ERR "move_member_tasks_to_cpuset: "
+ "cgroup_scan_tasks failed\n");
+}
+
/*
* If common_cpu_mem_hotplug_unplug(), below, unplugs any CPUs
* or memory nodes, we need to walk over the cpuset hierarchy,
* removing that CPU or node from all cpusets. If this removes the
- * last CPU or node from a cpuset, then the guarantee_online_cpus()
- * or guarantee_online_mems() code will use that emptied cpusets
- * parent online CPUs or nodes. Cpusets that were already empty of
- * CPUs or nodes are left empty.
+ * last CPU or node from a cpuset, then move the tasks in the empty
+ * cpuset to its next-highest non-empty parent.
*
- * This routine is intentionally inefficient in a couple of regards.
- * It will check all cpusets in a subtree even if the top cpuset of
- * the subtree has no offline CPUs or nodes. It checks both CPUs and
- * nodes, even though the caller could have been coded to know that
- * only one of CPUs or nodes needed to be checked on a given call.
- * This was done to minimize text size rather than cpu cycles.
+ * Called with cgroup_mutex held
+ * callback_mutex must not be held, as cpuset_attach() will take it.
+ */
+static void remove_tasks_in_empty_cpuset(struct cpuset *cs)
+{
+ struct cpuset *parent;
+
+ /*
+ * The cgroup's css_sets list is in use if there are tasks
+ * in the cpuset; the list is empty if there are none;
+ * the cs->css.refcnt seems always 0.
+ */
+ if (list_empty(&cs->css.cgroup->css_sets))
+ return;
+
+ /*
+ * Find its next-highest non-empty parent, (top cpuset
+ * has online cpus, so can't be empty).
+ */
+ parent = cs->parent;
+ while (cpus_empty(parent->cpus_allowed) ||
+ nodes_empty(parent->mems_allowed))
+ parent = parent->parent;
+
+ move_member_tasks_to_cpuset(cs, parent);
+}
+
+/*
+ * Walk the specified cpuset subtree and look for empty cpusets.
+ * The tasks of such cpuset must be moved to a parent cpuset.
+ *
+ * Called with cgroup_mutex held. We take callback_mutex to modify
+ * cpus_allowed and mems_allowed.
*
- * Call with both manage_mutex and callback_mutex held.
+ * This walk processes the tree from top to bottom, completing one layer
+ * before dropping down to the next. It always processes a node before
+ * any of its children.
*
- * Recursive, on depth of cpuset subtree.
+ * For now, since we lack memory hot unplug, we'll never see a cpuset
+ * that has tasks along with an empty 'mems'. But if we did see such
+ * a cpuset, we'd handle it just like we do if its 'cpus' was empty.
*/
-
-static void guarantee_online_cpus_mems_in_subtree(const struct cpuset *cur)
+static void scan_for_empty_cpusets(const struct cpuset *root)
{
+ struct cpuset *cp; /* scans cpusets being updated */
+ struct cpuset *child; /* scans child cpusets of cp */
+ struct list_head queue;
struct cgroup *cont;
- struct cpuset *c;
- /* Each of our child cpusets mems must be online */
- list_for_each_entry(cont, &cur->css.cgroup->children, sibling) {
- c = cgroup_cs(cont);
- guarantee_online_cpus_mems_in_subtree(c);
- if (!cpus_empty(c->cpus_allowed))
- guarantee_online_cpus(c, &c->cpus_allowed);
- if (!nodes_empty(c->mems_allowed))
- guarantee_online_mems(c, &c->mems_allowed);
+ INIT_LIST_HEAD(&queue);
+
+ list_add_tail((struct list_head *)&root->stack_list, &queue);
+
+ while (!list_empty(&queue)) {
+ cp = container_of(queue.next, struct cpuset, stack_list);
+ list_del(queue.next);
+ list_for_each_entry(cont, &cp->css.cgroup->children, sibling) {
+ child = cgroup_cs(cont);
+ list_add_tail(&child->stack_list, &queue);
+ }
+ cont = cp->css.cgroup;
+
+ /* Continue past cpusets with all cpus, mems online */
+ if (cpus_subset(cp->cpus_allowed, cpu_online_map) &&
+ nodes_subset(cp->mems_allowed, node_states[N_HIGH_MEMORY]))
+ continue;
+
+ /* Remove offline cpus and mems from this cpuset. */
+ mutex_lock(&callback_mutex);
+ cpus_and(cp->cpus_allowed, cp->cpus_allowed, cpu_online_map);
+ nodes_and(cp->mems_allowed, cp->mems_allowed,
+ node_states[N_HIGH_MEMORY]);
+ mutex_unlock(&callback_mutex);
+
+ /* Move tasks from the empty cpuset to a parent */
+ if (cpus_empty(cp->cpus_allowed) ||
+ nodes_empty(cp->mems_allowed))
+ remove_tasks_in_empty_cpuset(cp);
}
}
/*
* The cpus_allowed and mems_allowed nodemasks in the top_cpuset track
* cpu_online_map and node_states[N_HIGH_MEMORY]. Force the top cpuset to
- * track what's online after any CPU or memory node hotplug or unplug
- * event.
- *
- * To ensure that we don't remove a CPU or node from the top cpuset
- * that is currently in use by a child cpuset (which would violate
- * the rule that cpusets must be subsets of their parent), we first
- * call the recursive routine guarantee_online_cpus_mems_in_subtree().
+ * track what's online after any CPU or memory node hotplug or unplug event.
*
* Since there are two callers of this routine, one for CPU hotplug
* events and one for memory node hotplug events, we could have coded
@@ -1744,13 +1784,11 @@ static void guarantee_online_cpus_mems_in_subtree(const struct cpuset *cur)
static void common_cpu_mem_hotplug_unplug(void)
{
cgroup_lock();
- mutex_lock(&callback_mutex);
- guarantee_online_cpus_mems_in_subtree(&top_cpuset);
top_cpuset.cpus_allowed = cpu_online_map;
top_cpuset.mems_allowed = node_states[N_HIGH_MEMORY];
+ scan_for_empty_cpusets(&top_cpuset);
- mutex_unlock(&callback_mutex);
cgroup_unlock();
}
@@ -1826,7 +1864,7 @@ cpumask_t cpuset_cpus_allowed(struct task_struct *tsk)
/**
* cpuset_cpus_allowed_locked - return cpus_allowed mask from a tasks cpuset.
- * Must be called with callback_mutex held.
+ * Must be called with callback_mutex held.
**/
cpumask_t cpuset_cpus_allowed_locked(struct task_struct *tsk)
{
@@ -2163,10 +2201,8 @@ void __cpuset_memory_pressure_bump(void)
* - Used for /proc/<pid>/cpuset.
* - No need to task_lock(tsk) on this tsk->cpuset reference, as it
* doesn't really matter if tsk->cpuset changes after we read it,
- * and we take manage_mutex, keeping attach_task() from changing it
- * anyway. No need to check that tsk->cpuset != NULL, thanks to
- * the_top_cpuset_hack in cpuset_exit(), which sets an exiting tasks
- * cpuset to top_cpuset.
+ * and we take cgroup_mutex, keeping cpuset_attach() from changing it
+ * anyway.
*/
static int proc_cpuset_show(struct seq_file *m, void *unused_v)
{
diff --git a/kernel/fork.c b/kernel/fork.c
index 3995297567a..b2ef8e4fad7 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -40,6 +40,7 @@
#include <linux/ptrace.h>
#include <linux/mount.h>
#include <linux/audit.h>
+#include <linux/memcontrol.h>
#include <linux/profile.h>
#include <linux/rmap.h>
#include <linux/acct.h>
@@ -340,7 +341,7 @@ __cacheline_aligned_in_smp DEFINE_SPINLOCK(mmlist_lock);
#include <linux/init_task.h>
-static struct mm_struct * mm_init(struct mm_struct * mm)
+static struct mm_struct * mm_init(struct mm_struct * mm, struct task_struct *p)
{
atomic_set(&mm->mm_users, 1);
atomic_set(&mm->mm_count, 1);
@@ -357,11 +358,14 @@ static struct mm_struct * mm_init(struct mm_struct * mm)
mm->ioctx_list = NULL;
mm->free_area_cache = TASK_UNMAPPED_BASE;
mm->cached_hole_size = ~0UL;
+ mm_init_cgroup(mm, p);
if (likely(!mm_alloc_pgd(mm))) {
mm->def_flags = 0;
return mm;
}
+
+ mm_free_cgroup(mm);
free_mm(mm);
return NULL;
}
@@ -376,7 +380,7 @@ struct mm_struct * mm_alloc(void)
mm = allocate_mm();
if (mm) {
memset(mm, 0, sizeof(*mm));
- mm = mm_init(mm);
+ mm = mm_init(mm, current);
}
return mm;
}
@@ -390,6 +394,7 @@ void fastcall __mmdrop(struct mm_struct *mm)
{
BUG_ON(mm == &init_mm);
mm_free_pgd(mm);
+ mm_free_cgroup(mm);
destroy_context(mm);
free_mm(mm);
}
@@ -511,7 +516,7 @@ static struct mm_struct *dup_mm(struct task_struct *tsk)
mm->token_priority = 0;
mm->last_interval = 0;
- if (!mm_init(mm))
+ if (!mm_init(mm, tsk))
goto fail_nomem;
if (init_new_context(tsk, mm))
diff --git a/kernel/kexec.c b/kernel/kexec.c
index 9a26eec9eb0..06a0e277565 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -1361,8 +1361,8 @@ unsigned long __attribute__ ((weak)) paddr_vmcoreinfo_note(void)
static int __init crash_save_vmcoreinfo_init(void)
{
- vmcoreinfo_append_str("OSRELEASE=%s\n", init_uts_ns.name.release);
- vmcoreinfo_append_str("PAGESIZE=%ld\n", PAGE_SIZE);
+ VMCOREINFO_OSRELEASE(init_uts_ns.name.release);
+ VMCOREINFO_PAGESIZE(PAGE_SIZE);
VMCOREINFO_SYMBOL(init_uts_ns);
VMCOREINFO_SYMBOL(node_online_map);
@@ -1376,15 +1376,15 @@ static int __init crash_save_vmcoreinfo_init(void)
#ifdef CONFIG_SPARSEMEM
VMCOREINFO_SYMBOL(mem_section);
VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS);
- VMCOREINFO_SIZE(mem_section);
+ VMCOREINFO_STRUCT_SIZE(mem_section);
VMCOREINFO_OFFSET(mem_section, section_mem_map);
#endif
- VMCOREINFO_SIZE(page);
- VMCOREINFO_SIZE(pglist_data);
- VMCOREINFO_SIZE(zone);
- VMCOREINFO_SIZE(free_area);
- VMCOREINFO_SIZE(list_head);
- VMCOREINFO_TYPEDEF_SIZE(nodemask_t);
+ VMCOREINFO_STRUCT_SIZE(page);
+ VMCOREINFO_STRUCT_SIZE(pglist_data);
+ VMCOREINFO_STRUCT_SIZE(zone);
+ VMCOREINFO_STRUCT_SIZE(free_area);
+ VMCOREINFO_STRUCT_SIZE(list_head);
+ VMCOREINFO_SIZE(nodemask_t);
VMCOREINFO_OFFSET(page, flags);
VMCOREINFO_OFFSET(page, _count);
VMCOREINFO_OFFSET(page, mapping);
diff --git a/kernel/pid.c b/kernel/pid.c
index f815455431b..3b30bccdfcd 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -368,6 +368,7 @@ struct task_struct * fastcall pid_task(struct pid *pid, enum pid_type type)
}
return result;
}
+EXPORT_SYMBOL(pid_task);
/*
* Must be called under rcu_read_lock() or with tasklist_lock read-held.
diff --git a/kernel/res_counter.c b/kernel/res_counter.c
new file mode 100644
index 00000000000..16cbec2d5d6
--- /dev/null
+++ b/kernel/res_counter.c
@@ -0,0 +1,134 @@
+/*
+ * resource cgroups
+ *
+ * Copyright 2007 OpenVZ SWsoft Inc
+ *
+ * Author: Pavel Emelianov <xemul@openvz.org>
+ *
+ */
+
+#include <linux/types.h>
+#include <linux/parser.h>
+#include <linux/fs.h>
+#include <linux/res_counter.h>
+#include <linux/uaccess.h>
+
+void res_counter_init(struct res_counter *counter)
+{
+ spin_lock_init(&counter->lock);
+ counter->limit = (unsigned long long)LLONG_MAX;
+}
+
+int res_counter_charge_locked(struct res_counter *counter, unsigned long val)
+{
+ if (counter->usage + val > counter->limit) {
+ counter->failcnt++;
+ return -ENOMEM;
+ }
+
+ counter->usage += val;
+ return 0;
+}
+
+int res_counter_charge(struct res_counter *counter, unsigned long val)
+{
+ int ret;
+ unsigned long flags;
+
+ spin_lock_irqsave(&counter->lock, flags);
+ ret = res_counter_charge_locked(counter, val);
+ spin_unlock_irqrestore(&counter->lock, flags);
+ return ret;
+}
+
+void res_counter_uncharge_locked(struct res_counter *counter, unsigned long val)
+{
+ if (WARN_ON(counter->usage < val))
+ val = counter->usage;
+
+ counter->usage -= val;
+}
+
+void res_counter_uncharge(struct res_counter *counter, unsigned long val)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&counter->lock, flags);
+ res_counter_uncharge_locked(counter, val);
+ spin_unlock_irqrestore(&counter->lock, flags);
+}
+
+
+static inline unsigned long long *
+res_counter_member(struct res_counter *counter, int member)
+{
+ switch (member) {
+ case RES_USAGE:
+ return &counter->usage;
+ case RES_LIMIT:
+ return &counter->limit;
+ case RES_FAILCNT:
+ return &counter->failcnt;
+ };
+
+ BUG();
+ return NULL;
+}
+
+ssize_t res_counter_read(struct res_counter *counter, int member,
+ const char __user *userbuf, size_t nbytes, loff_t *pos,
+ int (*read_strategy)(unsigned long long val, char *st_buf))
+{
+ unsigned long long *val;
+ char buf[64], *s;
+
+ s = buf;
+ val = res_counter_member(counter, member);
+ if (read_strategy)
+ s += read_strategy(*val, s);
+ else
+ s += sprintf(s, "%llu\n", *val);
+ return simple_read_from_buffer((void __user *)userbuf, nbytes,
+ pos, buf, s - buf);
+}
+
+ssize_t res_counter_write(struct res_counter *counter, int member,
+ const char __user *userbuf, size_t nbytes, loff_t *pos,
+ int (*write_strategy)(char *st_buf, unsigned long long *val))
+{
+ int ret;
+ char *buf, *end;
+ unsigned long flags;
+ unsigned long long tmp, *val;
+
+ buf = kmalloc(nbytes + 1, GFP_KERNEL);
+ ret = -ENOMEM;
+ if (buf == NULL)
+ goto out;
+
+ buf[nbytes] = '\0';
+ ret = -EFAULT;
+ if (copy_from_user(buf, userbuf, nbytes))
+ goto out_free;
+
+ ret = -EINVAL;
+
+ if (write_strategy) {
+ if (write_strategy(buf, &tmp)) {
+ goto out_free;
+ }
+ } else {
+ tmp = simple_strtoull(buf, &end, 10);
+ if (*end != '\0')
+ goto out_free;
+ }
+ spin_lock_irqsave(&counter->lock, flags);
+ val = res_counter_member(counter, member);
+ *val = tmp;
+ spin_unlock_irqrestore(&counter->lock, flags);
+ ret = nbytes;
+out_free:
+ kfree(buf);
+out:
+ return ret;
+}
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 86daaa26d12..8c98d8147d8 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -67,6 +67,7 @@ extern int sysctl_overcommit_memory;
extern int sysctl_overcommit_ratio;
extern int sysctl_panic_on_oom;
extern int sysctl_oom_kill_allocating_task;
+extern int sysctl_oom_dump_tasks;
extern int max_threads;
extern int core_uses_pid;
extern int suid_dumpable;
@@ -871,6 +872,14 @@ static struct ctl_table vm_table[] = {
.proc_handler = &proc_dointvec,
},
{
+ .ctl_name = CTL_UNNUMBERED,
+ .procname = "oom_dump_tasks",
+ .data = &sysctl_oom_dump_tasks,
+ .maxlen = sizeof(sysctl_oom_dump_tasks),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec,
+ },
+ {
.ctl_name = VM_OVERCOMMIT_RATIO,
.procname = "overcommit_ratio",
.data = &sysctl_overcommit_ratio,
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-27 11:57:12 +0000