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| author | Ingo Molnar <mingo@elte.hu> | 2009-05-04 19:23:18 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-05-04 19:30:42 +0200 |
| commit | 1dce8d99b85aba6eddb8b8260baea944922e6fe7 (patch) | |
| tree | 77afc73743f8eb1c81b652418661b98b1f4b933d /kernel | |
| parent | perf_counter: initialize the per-cpu context earlier (diff) | |
| download | linux-1dce8d99b85aba6eddb8b8260baea944922e6fe7.tar.xz linux-1dce8d99b85aba6eddb8b8260baea944922e6fe7.zip | |
perf_counter: convert perf_resource_mutex to a spinlock
Now percpu counters can be initialized very early. But the init
sequence uses mutex_lock(). Fortunately, perf_resource_mutex should
be a spinlock anyway, so convert it.
[ Impact: fix crash due to early init mutex use ]
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/perf_counter.c | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index fcdafa234a5d..5f86a1156c94 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -46,9 +46,9 @@ static atomic_t nr_comm_tracking __read_mostly; int sysctl_perf_counter_priv __read_mostly; /* do we need to be privileged */ /* - * Mutex for (sysadmin-configurable) counter reservations: + * Lock for (sysadmin-configurable) counter reservations: */ -static DEFINE_MUTEX(perf_resource_mutex); +static DEFINE_SPINLOCK(perf_resource_lock); /* * Architecture provided APIs - weak aliases: @@ -3207,9 +3207,9 @@ static void __cpuinit perf_counter_init_cpu(int cpu) cpuctx = &per_cpu(perf_cpu_context, cpu); __perf_counter_init_context(&cpuctx->ctx, NULL); - mutex_lock(&perf_resource_mutex); + spin_lock(&perf_resource_lock); cpuctx->max_pertask = perf_max_counters - perf_reserved_percpu; - mutex_unlock(&perf_resource_mutex); + spin_unlock(&perf_resource_lock); hw_perf_counter_setup(cpu); } @@ -3292,7 +3292,7 @@ perf_set_reserve_percpu(struct sysdev_class *class, if (val > perf_max_counters) return -EINVAL; - mutex_lock(&perf_resource_mutex); + spin_lock(&perf_resource_lock); perf_reserved_percpu = val; for_each_online_cpu(cpu) { cpuctx = &per_cpu(perf_cpu_context, cpu); @@ -3302,7 +3302,7 @@ perf_set_reserve_percpu(struct sysdev_class *class, cpuctx->max_pertask = mpt; spin_unlock_irq(&cpuctx->ctx.lock); } - mutex_unlock(&perf_resource_mutex); + spin_unlock(&perf_resource_lock); return count; } @@ -3324,9 +3324,9 @@ perf_set_overcommit(struct sysdev_class *class, const char *buf, size_t count) if (val > 1) return -EINVAL; - mutex_lock(&perf_resource_mutex); + spin_lock(&perf_resource_lock); perf_overcommit = val; - mutex_unlock(&perf_resource_mutex); + spin_unlock(&perf_resource_lock); return count; } |