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authorJiri Olsa <jolsa@kernel.org>2017-08-03 14:21:14 +0300
committerArnaldo Carvalho de Melo <acme@redhat.com>2017-11-17 18:16:04 +0300
commit93d10af26bb7159349158b721ba2e258291d53c3 (patch)
treee476300cb6e6f32e23e79c453bf259b036829cd3 /tools/perf/builtin-kvm.c
parentdc83e1394083d6e12625a3158bf88396dfaec633 (diff)
downloadlinux-93d10af26bb7159349158b721ba2e258291d53c3.tar.xz
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>
Diffstat (limited to 'tools/perf/builtin-kvm.c')
-rw-r--r--tools/perf/builtin-kvm.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/tools/perf/builtin-kvm.c b/tools/perf/builtin-kvm.c
index cd253db6917f..597c7de9bec9 100644
--- a/tools/perf/builtin-kvm.c
+++ b/tools/perf/builtin-kvm.c
@@ -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++;