diff options
Diffstat (limited to 'kernel/perf_counter.c')
| -rw-r--r-- | kernel/perf_counter.c | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index 534e20d14d6..d7cbc579fc8 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -50,7 +50,7 @@ static atomic_t nr_task_counters __read_mostly; * 1 - disallow cpu counters to unpriv * 2 - disallow kernel profiling to unpriv */ -int sysctl_perf_counter_paranoid __read_mostly; +int sysctl_perf_counter_paranoid __read_mostly = 1; static inline bool perf_paranoid_cpu(void) { @@ -1503,10 +1503,21 @@ static void perf_counter_enable_on_exec(struct task_struct *task) */ static void __perf_counter_read(void *info) { + struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); struct perf_counter *counter = info; struct perf_counter_context *ctx = counter->ctx; unsigned long flags; + /* + * If this is a task context, we need to check whether it is + * the current task context of this cpu. If not it has been + * scheduled out before the smp call arrived. In that case + * counter->count would have been updated to a recent sample + * when the counter was scheduled out. + */ + if (ctx->task && cpuctx->task_ctx != ctx) + return; + local_irq_save(flags); if (ctx->is_active) update_context_time(ctx); @@ -1780,7 +1791,7 @@ static int perf_counter_read_group(struct perf_counter *counter, size += err; list_for_each_entry(sub, &leader->sibling_list, list_entry) { - err = perf_counter_read_entry(counter, read_format, + err = perf_counter_read_entry(sub, read_format, buf + size); if (err < 0) return err; @@ -2008,6 +2019,10 @@ int perf_counter_task_disable(void) return 0; } +#ifndef PERF_COUNTER_INDEX_OFFSET +# define PERF_COUNTER_INDEX_OFFSET 0 +#endif + static int perf_counter_index(struct perf_counter *counter) { if (counter->state != PERF_COUNTER_STATE_ACTIVE) @@ -4051,6 +4066,7 @@ perf_counter_alloc(struct perf_counter_attr *attr, hwc->sample_period = attr->sample_period; if (attr->freq && attr->sample_freq) hwc->sample_period = 1; + hwc->last_period = hwc->sample_period; atomic64_set(&hwc->period_left, hwc->sample_period); |