diff options
| author | Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | 2011-03-16 19:05:25 -0400 |
|---|---|---|
| committer | Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> | 2011-03-16 19:05:25 -0400 |
| commit | aae70d0e4b75f7d37aa49e48e316b3bab3092759 (patch) | |
| tree | 7293dacef497aa610a2b68b957c0b903778a31cc | |
| parent | 130ab0c3215436dd26b385ceaa797be7a86f380b (diff) | |
x86-trace-clock-use-spinlock
x86 trace-clock use spinlock
CPU hotplug notifiers should use spinlocks, not mutexes. They are not sleepable.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
| -rw-r--r-- | arch/x86/kernel/trace-clock.c | 15 |
1 files changed, 7 insertions, 8 deletions
diff --git a/arch/x86/kernel/trace-clock.c b/arch/x86/kernel/trace-clock.c index a5e45cb466e..b95e4ed2740 100644 --- a/arch/x86/kernel/trace-clock.c +++ b/arch/x86/kernel/trace-clock.c @@ -9,13 +9,12 @@ #include <linux/module.h> #include <linux/trace-clock.h> #include <linux/jiffies.h> -#include <linux/mutex.h> #include <linux/timer.h> #include <linux/cpu.h> static cycles_t trace_clock_last_tsc; static DEFINE_PER_CPU(struct timer_list, update_timer); -static DEFINE_MUTEX(async_tsc_mutex); +static DEFINE_SPINLOCK(async_tsc_lock); static int async_tsc_refcount; /* Number of readers */ static int async_tsc_enabled; /* Async TSC enabled on all online CPUs */ @@ -140,7 +139,7 @@ static int __cpuinit hotcpu_callback(struct notifier_block *nb, unsigned int hotcpu = (unsigned long)hcpu; int cpu; - mutex_lock(&async_tsc_mutex); + spin_lock(&async_tsc_lock); switch (action) { case CPU_UP_PREPARE: case CPU_UP_PREPARE_FROZEN: @@ -184,7 +183,7 @@ static int __cpuinit hotcpu_callback(struct notifier_block *nb, break; #endif /* CONFIG_HOTPLUG_CPU */ } - mutex_unlock(&async_tsc_mutex); + spin_unlock(&async_tsc_lock); return NOTIFY_OK; } @@ -205,7 +204,7 @@ void get_trace_clock(void) } get_online_cpus(); - mutex_lock(&async_tsc_mutex); + spin_lock(&async_tsc_lock); if (async_tsc_refcount++ || trace_clock_is_sync()) goto end; @@ -213,7 +212,7 @@ void get_trace_clock(void) for_each_online_cpu(cpu) enable_trace_clock(cpu); end: - mutex_unlock(&async_tsc_mutex); + spin_unlock(&async_tsc_lock); put_online_cpus(); } EXPORT_SYMBOL_GPL(get_trace_clock); @@ -223,7 +222,7 @@ void put_trace_clock(void) int cpu; get_online_cpus(); - mutex_lock(&async_tsc_mutex); + spin_lock(&async_tsc_lock); WARN_ON(async_tsc_refcount <= 0); if (async_tsc_refcount != 1 || !async_tsc_enabled) goto end; @@ -235,7 +234,7 @@ end: async_tsc_refcount--; if (!async_tsc_refcount && num_online_cpus() == 1) set_trace_clock_is_sync(1); - mutex_unlock(&async_tsc_mutex); + spin_unlock(&async_tsc_lock); put_online_cpus(); } EXPORT_SYMBOL_GPL(put_trace_clock); |