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-rw-r--r--init/Kconfig46
-rw-r--r--init/do_mounts.c2
-rw-r--r--init/main.c30
3 files changed, 20 insertions, 58 deletions
diff --git a/init/Kconfig b/init/Kconfig
index 3f7e60995c8..8e8b76d8a27 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -316,38 +316,28 @@ choice
prompt "RCU Implementation"
default TREE_RCU
-config CLASSIC_RCU
- bool "Classic RCU"
- help
- This option selects the classic RCU implementation that is
- designed for best read-side performance on non-realtime
- systems.
-
- Select this option if you are unsure.
-
config TREE_RCU
bool "Tree-based hierarchical RCU"
help
This option selects the RCU implementation that is
designed for very large SMP system with hundreds or
- thousands of CPUs.
+ thousands of CPUs. It also scales down nicely to
+ smaller systems.
-config PREEMPT_RCU
- bool "Preemptible RCU"
+config TREE_PREEMPT_RCU
+ bool "Preemptable tree-based hierarchical RCU"
depends on PREEMPT
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.
+ This option selects the RCU implementation that is
+ designed for very large SMP systems with hundreds or
+ thousands of CPUs, but for which real-time response
+ is also required.
endchoice
config RCU_TRACE
bool "Enable tracing for RCU"
- depends on TREE_RCU || PREEMPT_RCU
+ depends on TREE_RCU || TREE_PREEMPT_RCU
help
This option provides tracing in RCU which presents stats
in debugfs for debugging RCU implementation.
@@ -359,7 +349,7 @@ config RCU_FANOUT
int "Tree-based hierarchical RCU fanout value"
range 2 64 if 64BIT
range 2 32 if !64BIT
- depends on TREE_RCU
+ depends on TREE_RCU || TREE_PREEMPT_RCU
default 64 if 64BIT
default 32 if !64BIT
help
@@ -374,7 +364,7 @@ config RCU_FANOUT
config RCU_FANOUT_EXACT
bool "Disable tree-based hierarchical RCU auto-balancing"
- depends on TREE_RCU
+ depends on TREE_RCU || TREE_PREEMPT_RCU
default n
help
This option forces use of the exact RCU_FANOUT value specified,
@@ -387,18 +377,12 @@ config RCU_FANOUT_EXACT
Say N if unsure.
config TREE_RCU_TRACE
- def_bool RCU_TRACE && TREE_RCU
- select DEBUG_FS
- help
- This option provides tracing for the TREE_RCU implementation,
- permitting Makefile to trivially select kernel/rcutree_trace.c.
-
-config PREEMPT_RCU_TRACE
- def_bool RCU_TRACE && PREEMPT_RCU
+ def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
select DEBUG_FS
help
- This option provides tracing for the PREEMPT_RCU implementation,
- permitting Makefile to trivially select kernel/rcupreempt_trace.c.
+ This option provides tracing for the TREE_RCU and
+ TREE_PREEMPT_RCU implementations, permitting Makefile to
+ trivially select kernel/rcutree_trace.c.
endmenu # "RCU Subsystem"
diff --git a/init/do_mounts.c b/init/do_mounts.c
index 093f6591550..bb008d064c1 100644
--- a/init/do_mounts.c
+++ b/init/do_mounts.c
@@ -415,7 +415,7 @@ void __init prepare_namespace(void)
mount_root();
out:
+ devtmpfs_mount("dev");
sys_mount(".", "/", NULL, MS_MOVE, NULL);
sys_chroot(".");
}
-
diff --git a/init/main.c b/init/main.c
index 9f110fbf0c4..a2086913a17 100644
--- a/init/main.c
+++ b/init/main.c
@@ -69,6 +69,7 @@
#include <linux/kmemcheck.h>
#include <linux/kmemtrace.h>
#include <linux/sfi.h>
+#include <linux/shmem_fs.h>
#include <trace/boot.h>
#include <asm/io.h>
@@ -354,7 +355,6 @@ static void __init smp_init(void)
#define smp_init() do { } while (0)
#endif
-static inline void setup_per_cpu_areas(void) { }
static inline void setup_nr_cpu_ids(void) { }
static inline void smp_prepare_cpus(unsigned int maxcpus) { }
@@ -375,29 +375,6 @@ static void __init setup_nr_cpu_ids(void)
nr_cpu_ids = find_last_bit(cpumask_bits(cpu_possible_mask),NR_CPUS) + 1;
}
-#ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA
-unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
-
-EXPORT_SYMBOL(__per_cpu_offset);
-
-static void __init setup_per_cpu_areas(void)
-{
- unsigned long size, i;
- char *ptr;
- unsigned long nr_possible_cpus = num_possible_cpus();
-
- /* Copy section for each CPU (we discard the original) */
- size = ALIGN(PERCPU_ENOUGH_ROOM, PAGE_SIZE);
- ptr = alloc_bootmem_pages(size * nr_possible_cpus);
-
- for_each_possible_cpu(i) {
- __per_cpu_offset[i] = ptr - __per_cpu_start;
- memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
- ptr += size;
- }
-}
-#endif /* CONFIG_HAVE_SETUP_PER_CPU_AREA */
-
/* Called by boot processor to activate the rest. */
static void __init smp_init(void)
{
@@ -452,6 +429,7 @@ static noinline void __init_refok rest_init(void)
{
int pid;
+ rcu_scheduler_starting();
kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND);
numa_default_policy();
pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
@@ -463,7 +441,6 @@ static noinline void __init_refok rest_init(void)
* at least once to get things moving:
*/
init_idle_bootup_task(current);
- rcu_scheduler_starting();
preempt_enable_no_resched();
schedule();
preempt_disable();
@@ -632,7 +609,6 @@ asmlinkage void __init start_kernel(void)
softirq_init();
timekeeping_init();
time_init();
- sched_clock_init();
profile_init();
if (!irqs_disabled())
printk(KERN_CRIT "start_kernel(): bug: interrupts were "
@@ -683,6 +659,7 @@ asmlinkage void __init start_kernel(void)
numa_policy_init();
if (late_time_init)
late_time_init();
+ sched_clock_init();
calibrate_delay();
pidmap_init();
anon_vma_init();
@@ -811,6 +788,7 @@ static void __init do_basic_setup(void)
init_workqueues();
cpuset_init_smp();
usermodehelper_init();
+ init_tmpfs();
driver_init();
init_irq_proc();
do_ctors();