diff options
| author | Kan Liang <kan.liang@intel.com> | 2016-03-23 21:24:37 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-06-03 10:40:15 +0300 |
| commit | f2fb6bef92514432398a653df1c2f1041d79ac46 (patch) | |
| tree | 4d576da877bc1ff5ee08f81d53339b91ea04ced8 /include/linux/perf_event.h | |
| parent | 42c4fb774782eead571f7379edf16b1138e7cebb (diff) | |
| download | linux-f2fb6bef92514432398a653df1c2f1041d79ac46.tar.xz | |
perf/core: Optimize side-band event delivery
The perf_event_aux() function iterates all PMUs and all events in
their respective per-CPU contexts to find the events to deliver
side-band records to.
For example, the brk test case in lkp triggers many mmap() operations,
which, if we're also running perf, results in many perf_event_aux()
invocations.
If we enable uncore PMU support (even when uncore events are not used),
dozens of uncore PMUs will be iterated, which can significantly
decrease brk_test's throughput.
For example, the brk throughput:
without uncore PMUs: 2647573 ops_per_sec
with uncore PMUs: 1768444 ops_per_sec
... a 33% reduction.
To get at the per-CPU events that need side-band records, this patch
puts these events on a per-CPU list, this avoids iterating the PMUs
and any events that do not need side-band records.
Per task events are unchanged to avoid extra overhead on the context
switch paths.
Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reported-by: Huang, Ying <ying.huang@linux.intel.com>
Signed-off-by: Kan Liang <kan.liang@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/1458757477-3781-1-git-send-email-kan.liang@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include/linux/perf_event.h')
| -rw-r--r-- | include/linux/perf_event.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 0e43355c7aad..92e9ce737432 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -517,6 +517,11 @@ struct swevent_hlist { struct perf_cgroup; struct ring_buffer; +struct pmu_event_list { + raw_spinlock_t lock; + struct list_head list; +}; + /** * struct perf_event - performance event kernel representation: */ @@ -675,6 +680,7 @@ struct perf_event { int cgrp_defer_enabled; #endif + struct list_head sb_list; #endif /* CONFIG_PERF_EVENTS */ }; |