diff options
| author | Ingo Molnar <mingo@elte.hu> | 2008-12-21 13:50:42 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-12-23 12:45:19 +0100 |
| commit | 95cdd2e7851cce79ab839cb0b3cbe68d7911d0f1 (patch) | |
| tree | fad7723f344027dd64a1ca44d0117c3da61b75ca /arch/x86 | |
| parent | 78b6084c907cea15bb40a564b974e072f5163781 (diff) | |
perfcounters: enable lowlevel pmc code to schedule counters
Allow lowlevel ->enable() op to return an error if a counter can not be
added. This can be used to handle counter constraints.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kernel/cpu/perf_counter.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/arch/x86/kernel/cpu/perf_counter.c b/arch/x86/kernel/cpu/perf_counter.c index b67557121425..74090a393a7c 100644 --- a/arch/x86/kernel/cpu/perf_counter.c +++ b/arch/x86/kernel/cpu/perf_counter.c @@ -244,7 +244,7 @@ static int fixed_mode_idx(struct hw_perf_counter *hwc) /* * Find a PMC slot for the freshly enabled / scheduled in counter: */ -static void pmc_generic_enable(struct perf_counter *counter) +static int pmc_generic_enable(struct perf_counter *counter) { struct cpu_hw_counters *cpuc = &__get_cpu_var(cpu_hw_counters); struct hw_perf_counter *hwc = &counter->hw; @@ -253,6 +253,8 @@ static void pmc_generic_enable(struct perf_counter *counter) /* Try to get the previous counter again */ if (test_and_set_bit(idx, cpuc->used)) { idx = find_first_zero_bit(cpuc->used, nr_counters_generic); + if (idx == nr_counters_generic) + return -EAGAIN; set_bit(idx, cpuc->used); hwc->idx = idx; } @@ -265,6 +267,8 @@ static void pmc_generic_enable(struct perf_counter *counter) __hw_perf_counter_set_period(counter, hwc, idx); __pmc_generic_enable(counter, hwc, idx); + + return 0; } void perf_counter_print_debug(void) |