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| author | Ingo Molnar <mingo@elte.hu> | 2009-05-04 19:13:30 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-05-04 19:30:32 +0200 |
| commit | 0d905bca23aca5c86a10ee101bcd3b1abbd40b25 (patch) | |
| tree | 5a4e6b956d1923ac1d28ae8b8f3034c1c90df5a5 | |
| parent | ba77813a2a22d631fe5bc0bf1ec0d11350544b70 (diff) | |
| download | kernel_samsung_crespo-0d905bca23aca5c86a10ee101bcd3b1abbd40b25.zip kernel_samsung_crespo-0d905bca23aca5c86a10ee101bcd3b1abbd40b25.tar.gz kernel_samsung_crespo-0d905bca23aca5c86a10ee101bcd3b1abbd40b25.tar.bz2 | |
perf_counter: initialize the per-cpu context earlier
percpu scheduling for perfcounters wants to take the context lock,
but that lock first needs to be initialized. Currently it is an
early_initcall() - but that is too late, the task tick runs much
sooner than that.
Call it explicitly from the scheduler init sequence instead.
[ Impact: fix access-before-init crash ]
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -rw-r--r-- | include/linux/perf_counter.h | 5 | ||||
| -rw-r--r-- | kernel/perf_counter.c | 5 | ||||
| -rw-r--r-- | kernel/sched.c | 5 |
3 files changed, 9 insertions, 6 deletions
diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h index f776851..a356fa6 100644 --- a/include/linux/perf_counter.h +++ b/include/linux/perf_counter.h @@ -573,6 +573,8 @@ extern struct perf_callchain_entry *perf_callchain(struct pt_regs *regs); extern int sysctl_perf_counter_priv; +extern void perf_counter_init(void); + #else static inline void perf_counter_task_sched_in(struct task_struct *task, int cpu) { } @@ -600,9 +602,10 @@ perf_counter_mmap(unsigned long addr, unsigned long len, static inline void perf_counter_munmap(unsigned long addr, unsigned long len, - unsigned long pgoff, struct file *file) { } + unsigned long pgoff, struct file *file) { } static inline void perf_counter_comm(struct task_struct *tsk) { } +static inline void perf_counter_init(void) { } #endif #endif /* __KERNEL__ */ diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index b9679c3..fcdafa2 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -3265,15 +3265,12 @@ static struct notifier_block __cpuinitdata perf_cpu_nb = { .notifier_call = perf_cpu_notify, }; -static int __init perf_counter_init(void) +void __init perf_counter_init(void) { perf_cpu_notify(&perf_cpu_nb, (unsigned long)CPU_UP_PREPARE, (void *)(long)smp_processor_id()); register_cpu_notifier(&perf_cpu_nb); - - return 0; } -early_initcall(perf_counter_init); static ssize_t perf_show_reserve_percpu(struct sysdev_class *class, char *buf) { diff --git a/kernel/sched.c b/kernel/sched.c index 2f600e3..a728976 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -39,6 +39,7 @@ #include <linux/completion.h> #include <linux/kernel_stat.h> #include <linux/debug_locks.h> +#include <linux/perf_counter.h> #include <linux/security.h> #include <linux/notifier.h> #include <linux/profile.h> @@ -8996,7 +8997,7 @@ void __init sched_init(void) * 1024) and two child groups A0 and A1 (of weight 1024 each), * then A0's share of the cpu resource is: * - * A0's bandwidth = 1024 / (10*1024 + 1024 + 1024) = 8.33% + * A0's bandwidth = 1024 / (10*1024 + 1024 + 1024) = 8.33% * * We achieve this by letting init_task_group's tasks sit * directly in rq->cfs (i.e init_task_group->se[] = NULL). @@ -9097,6 +9098,8 @@ void __init sched_init(void) alloc_bootmem_cpumask_var(&cpu_isolated_map); #endif /* SMP */ + perf_counter_init(); + scheduler_running = 1; } |