path: root/include/linux/perf_event.h
diff options
authorKan Liang <kan.liang@linux.intel.com>2020-11-30 11:38:40 -0800
committerIngo Molnar <mingo@kernel.org>2021-03-06 12:52:39 +0100
commita5398bffc01fe044848c5024e5e867e407f239b8 (patch)
tree4024bf63256a99173f8c38e49de68debed41657e /include/linux/perf_event.h
parentLinux 5.12-rc2 (diff)
perf/core: Flush PMU internal buffers for per-CPU events
Sometimes the PMU internal buffers have to be flushed for per-CPU events during a context switch, e.g., large PEBS. Otherwise, the perf tool may report samples in locations that do not belong to the process where the samples are processed in, because PEBS does not tag samples with PID/TID. The current code only flush the buffers for a per-task event. It doesn't check a per-CPU event. Add a new event state flag, PERF_ATTACH_SCHED_CB, to indicate that the PMU internal buffers have to be flushed for this event during a context switch. Add sched_cb_entry and perf_sched_cb_usages back to track the PMU/cpuctx which is required to be flushed. Only need to invoke the sched_task() for per-CPU events in this patch. The per-task events have been handled in perf_event_context_sched_in/out already. Fixes: 9c964efa4330 ("perf/x86/intel: Drain the PEBS buffer during context switches") Reported-by: Gabriel Marin <gmx@google.com> Originally-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lkml.kernel.org/r/20201130193842.10569-1-kan.liang@linux.intel.com
Diffstat (limited to 'include/linux/perf_event.h')
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index fab42cfbd350..3f7f89ea5e51 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -606,6 +606,7 @@ struct swevent_hlist {
#define PERF_ATTACH_TASK 0x04
+#define PERF_ATTACH_SCHED_CB 0x20
struct perf_cgroup;
struct perf_buffer;
@@ -872,6 +873,7 @@ struct perf_cpu_context {
struct list_head cgrp_cpuctx_entry;
+ struct list_head sched_cb_entry;
int sched_cb_usage;
int online;