openkylin
/
linux
mirror of https://gitee.com/openkylin/linux.git
9
0
Fork 0
Code Issues Projects Releases Wiki Activity

perf tools: Optimize sample parsing for ordered events 

Currently when using ordered events we parse the sample twice (the
perf_evlist__parse_sample function). Once before we queue the sample for
sorting:

  perf_session__process_event
    perf_evlist__parse_sample(sample)
    perf_session__queue_event(sample.time)

And then when we deliver the sorted sample:

  ordered_events__deliver_event
    perf_evlist__parse_sample
    perf_session__deliver_event

We can skip the initial full sample parsing by using
perf_evlist__parse_sample_timestamp function, which got introduced
earlier. The new path looks like:

  perf_session__process_event
    perf_evlist__parse_sample_timestamp
    perf_session__queue_event

  ordered_events__deliver_event
    perf_session__deliver_event
      perf_evlist__parse_sample

It saves some instructions and is slightly faster:

Before:
 Performance counter stats for './perf.old report --stdio' (5 runs):

    64,396,007,225      cycles:u                                                      ( +-  0.97% )
   105,882,112,735      instructions:u            #    1.64  insn per cycle           ( +-  0.00% )

      21.618103465 seconds time elapsed                                          ( +-  1.12% )

After:
 Performance counter stats for './perf report --stdio' (5 runs):

    60,567,807,182      cycles:u                                                      ( +-  0.40% )
   104,853,333,514      instructions:u            #    1.73  insn per cycle           ( +-  0.00% )

      20.168895243 seconds time elapsed                                          ( +-  0.32% )

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-cjp2tuk0qkjs9dxzlpmm34ua@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Jiri Olsa 2017-08-03 13:21:14 +02:00 committed by Arnaldo Carvalho de Melo
parent dc83e13940
commit 93d10af26b
2 changed files with 22 additions and 27 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
tools/perf/builtin-kvm.c
View File

@ -741,20 +741,20 @@ static s64 perf_kvm__mmap_read_idx(struct perf_kvm_stat *kvm, int idx,
u64 *mmap_time)
{
union perf_event *event;
struct perf_sample sample;
u64 timestamp;
s64 n = 0;
int err;
*mmap_time = ULLONG_MAX;
while ((event = perf_evlist__mmap_read(kvm->evlist, idx)) != NULL) {
err = perf_evlist__parse_sample(kvm->evlist, event, &sample);
err = perf_evlist__parse_sample_timestamp(kvm->evlist, event, &timestamp);
if (err) {
perf_evlist__mmap_consume(kvm->evlist, idx);
pr_err("Failed to parse sample\n");
return -1;
}
err = perf_session__queue_event(kvm->session, event, sample.time, 0);
err = perf_session__queue_event(kvm->session, event, timestamp, 0);
/*
* FIXME: Here we can't consume the event, as perf_session__queue_event will
* point to it, and it'll get possibly overwritten by the kernel.
@ -768,7 +768,7 @@ static s64 perf_kvm__mmap_read_idx(struct perf_kvm_stat *kvm, int idx,
/* save time stamp of our first sample for this mmap */
if (n == 0)
*mmap_time = sample.time;
*mmap_time = timestamp;
/* limit events per mmap handled all at once */
n++;

41
tools/perf/util/session.c
View File

@ -27,7 +27,6 @@
static int perf_session__deliver_event(struct perf_session *session,
union perf_event *event,
struct perf_sample *sample,
struct perf_tool *tool,
u64 file_offset);
@ -107,17 +106,10 @@ static void perf_session__set_comm_exec(struct perf_session *session)
static int ordered_events__deliver_event(struct ordered_events *oe,
struct ordered_event *event)
{
struct perf_sample sample;
struct perf_session *session = container_of(oe, struct perf_session,
ordered_events);
int ret = perf_evlist__parse_sample(session->evlist, event->event, &sample);
if (ret) {
pr_err("Can't parse sample, err = %d\n", ret);
return ret;
}
return perf_session__deliver_event(session, event->event, &sample,
return perf_session__deliver_event(session, event->event,
session->tool, event->file_offset);
}
@ -1328,20 +1320,26 @@ static int machines__deliver_event(struct machines *machines,
static int perf_session__deliver_event(struct perf_session *session,
union perf_event *event,
struct perf_sample *sample,
struct perf_tool *tool,
u64 file_offset)
{
struct perf_sample sample;
int ret;
ret = auxtrace__process_event(session, event, sample, tool);
ret = perf_evlist__parse_sample(session->evlist, event, &sample);
if (ret) {
pr_err("Can't parse sample, err = %d\n", ret);
return ret;
}
ret = auxtrace__process_event(session, event, &sample, tool);
if (ret < 0)
return ret;
if (ret > 0)
return 0;
return machines__deliver_event(&session->machines, session->evlist,
event, sample, tool, file_offset);
event, &sample, tool, file_offset);
}
static s64 perf_session__process_user_event(struct perf_session *session,
@ -1495,7 +1493,6 @@ static s64 perf_session__process_event(struct perf_session *session,
{
struct perf_evlist *evlist = session->evlist;
struct perf_tool *tool = session->tool;
struct perf_sample sample;
int ret;
if (session->header.needs_swap)
@ -1509,21 +1506,19 @@ static s64 perf_session__process_event(struct perf_session *session,
if (event->header.type >= PERF_RECORD_USER_TYPE_START)
return perf_session__process_user_event(session, event, file_offset);
/*
* For all kernel events we get the sample data
*/
ret = perf_evlist__parse_sample(evlist, event, &sample);
if (ret)
return ret;
if (tool->ordered_events) {
ret = perf_session__queue_event(session, event, sample.time, file_offset);
u64 timestamp;
ret = perf_evlist__parse_sample_timestamp(evlist, event, &timestamp);
if (ret)
return ret;
ret = perf_session__queue_event(session, event, timestamp, file_offset);
if (ret != -ETIME)
return ret;
}
return perf_session__deliver_event(session, event, &sample, tool,
file_offset);
return perf_session__deliver_event(session, event, tool, file_offset);
}
void perf_event_header__bswap(struct perf_event_header *hdr)