diff options
| -rw-r--r-- | include/linux/perf_counter.h | 7 | ||||
| -rw-r--r-- | kernel/perf_counter.c | 26 |
2 files changed, 33 insertions, 0 deletions
diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h index 56099e52970..18dc17d0a61 100644 --- a/include/linux/perf_counter.h +++ b/include/linux/perf_counter.h @@ -328,6 +328,13 @@ struct perf_cpu_context { int active_oncpu; int max_pertask; int exclusive; + + /* + * Recursion avoidance: + * + * task, softirq, irq, nmi context + */ + int recursion[4]; }; /* diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index ca14fc41ccd..ce34bff07bd 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -23,6 +23,7 @@ #include <linux/mm.h> #include <linux/vmstat.h> #include <linux/rculist.h> +#include <linux/hardirq.h> #include <asm/irq_regs.h> @@ -1532,10 +1533,31 @@ static void perf_swcounter_ctx_event(struct perf_counter_context *ctx, rcu_read_unlock(); } +static int *perf_swcounter_recursion_context(struct perf_cpu_context *cpuctx) +{ + if (in_nmi()) + return &cpuctx->recursion[3]; + + if (in_irq()) + return &cpuctx->recursion[2]; + + if (in_softirq()) + return &cpuctx->recursion[1]; + + return &cpuctx->recursion[0]; +} + static void __perf_swcounter_event(enum perf_event_types type, u32 event, u64 nr, int nmi, struct pt_regs *regs) { struct perf_cpu_context *cpuctx = &get_cpu_var(perf_cpu_context); + int *recursion = perf_swcounter_recursion_context(cpuctx); + + if (*recursion) + goto out; + + (*recursion)++; + barrier(); perf_swcounter_ctx_event(&cpuctx->ctx, type, event, nr, nmi, regs); if (cpuctx->task_ctx) { @@ -1543,6 +1565,10 @@ static void __perf_swcounter_event(enum perf_event_types type, u32 event, nr, nmi, regs); } + barrier(); + (*recursion)--; + +out: put_cpu_var(perf_cpu_context); } |