| Message ID | 1544114849-47266-4-git-send-email-andrew.murray@arm.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | perf/core: Generalise event exclusion checking | expand |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/apply_patch | success | next/apply_patch Successfully applied |
| snowpatch_ozlabs/checkpatch | warning | total: 0 errors, 0 warnings, 1 checks, 22 lines checked |
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index b2e806f..fe92b89 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -244,6 +244,7 @@ struct perf_event; #define PERF_PMU_CAP_EXCLUSIVE 0x10 #define PERF_PMU_CAP_ITRACE 0x20 #define PERF_PMU_CAP_HETEROGENEOUS_CPUS 0x40 +#define PERF_PMU_CAP_NO_EXCLUDE 0x80 /** * struct pmu - generic performance monitoring unit diff --git a/kernel/events/core.c b/kernel/events/core.c index 5a97f34..5113cfc 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -9743,6 +9743,15 @@ static int perf_try_init_event(struct pmu *pmu, struct perf_event *event) if (ctx) perf_event_ctx_unlock(event->group_leader, ctx); + if (!ret) { + if (pmu->capabilities & PERF_PMU_CAP_NO_EXCLUDE && + event_has_any_exclude_flag(event)) { + if (event->destroy) + event->destroy(event); + ret = -EINVAL; + } + } + if (ret) module_put(pmu->module);
Many PMU drivers do not have the capability to exclude counting events that occur in specific contexts such as idle, kernel, guest, etc. These drivers indicate this by returning an error in their event_init upon testing the events attribute flags. This approach is error prone and often inconsistent. Let's instead allow PMU drivers to advertise their inability to exclude based on context via a new capability: PERF_PMU_CAP_NO_EXCLUDE. This allows the perf core to reject requests for exclusion events where there is no support in the PMU. Signed-off-by: Andrew Murray <andrew.murray@arm.com> --- include/linux/perf_event.h | 1 + kernel/events/core.c | 9 +++++++++ 2 files changed, 10 insertions(+)