diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2009-05-04 18:47:44 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-05-04 19:30:29 +0200 |
| commit | ba77813a2a22d631fe5bc0bf1ec0d11350544b70 (patch) | |
| tree | 09fd04be43e2c221aff774bf95e7bfb4d213bb17 | |
| parent | b82914ce33146186d554b0f5c41e4e13693614ce (diff) | |
perf_counter: x86: fixup nmi_watchdog vs perf_counter boo-boo
Invert the atomic_inc_not_zero() test so that we will indeed detect the
first activation.
Also rename the global num_counters, since its easy to confuse with
x86_pmu.num_counters.
[ Impact: fix non-working perfcounters on AMD CPUs, cleanup ]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1241455664.7620.4938.camel@twins>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -rw-r--r-- | arch/x86/kernel/cpu/perf_counter.c | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/arch/x86/kernel/cpu/perf_counter.c b/arch/x86/kernel/cpu/perf_counter.c index d4c0cc9d326..196b58f0444 100644 --- a/arch/x86/kernel/cpu/perf_counter.c +++ b/arch/x86/kernel/cpu/perf_counter.c @@ -171,7 +171,7 @@ again: return new_raw_count; } -static atomic_t num_counters; +static atomic_t active_counters; static DEFINE_MUTEX(pmc_reserve_mutex); static bool reserve_pmc_hardware(void) @@ -224,7 +224,7 @@ static void release_pmc_hardware(void) static void hw_perf_counter_destroy(struct perf_counter *counter) { - if (atomic_dec_and_mutex_lock(&num_counters, &pmc_reserve_mutex)) { + if (atomic_dec_and_mutex_lock(&active_counters, &pmc_reserve_mutex)) { release_pmc_hardware(); mutex_unlock(&pmc_reserve_mutex); } @@ -248,12 +248,12 @@ static int __hw_perf_counter_init(struct perf_counter *counter) return -ENODEV; err = 0; - if (atomic_inc_not_zero(&num_counters)) { + if (!atomic_inc_not_zero(&active_counters)) { mutex_lock(&pmc_reserve_mutex); - if (atomic_read(&num_counters) == 0 && !reserve_pmc_hardware()) + if (atomic_read(&active_counters) == 0 && !reserve_pmc_hardware()) err = -EBUSY; else - atomic_inc(&num_counters); + atomic_inc(&active_counters); mutex_unlock(&pmc_reserve_mutex); } if (err) @@ -280,7 +280,7 @@ static int __hw_perf_counter_init(struct perf_counter *counter) if (capable(CAP_SYS_ADMIN) && hw_event->nmi) hwc->nmi = 1; - hwc->irq_period = hw_event->irq_period; + hwc->irq_period = hw_event->irq_period; if ((s64)hwc->irq_period <= 0 || hwc->irq_period > x86_pmu.max_period) hwc->irq_period = x86_pmu.max_period; @@ -871,7 +871,7 @@ perf_counter_nmi_handler(struct notifier_block *self, struct pt_regs *regs; int ret; - if (!atomic_read(&num_counters)) + if (!atomic_read(&active_counters)) return NOTIFY_DONE; switch (cmd) { |