redonkable
/
alistair23-linux
1
0
Fork 0
Code Releases Activity

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>
hifive-unleashed-5.1
Ingo Molnar 2009-05-04 19:23:18 +02:00
parent 0d905bca23
commit 1dce8d99b8
1 changed files with 8 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
kernel/perf_counter.c
View File

@ -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;
}