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authorDavidlohr Bueso <davidlohr@hp.com>2013-09-08 19:19:19 -0700
committerArnaldo Carvalho de Melo <acme@redhat.com>2013-10-09 11:24:01 -0300
commitf37376cd721a539ac398cbb7718b72fce83cd49b (patch)
tree2af484293bd583c2af6ed313011fa2592259b89e /tools/perf
parent60a25cbc4a167fc0129296c3c640d8506a57acc5 (diff)
downloadlinux-f37376cd721a539ac398cbb7718b72fce83cd49b.tar.gz
perf lock: Account for lock average wait time
While perf-lock currently reports both the total wait time and the number of contentions, it doesn't explicitly show the average wait time. Having this value immediately in the report can be quite useful when looking into performance issues. Furthermore, allowing report to sort by averages is another handy feature to have - and thus do not only print the value, but add it to the lock_stat structure. Signed-off-by: Davidlohr Bueso <davidlohr@hp.com> Cc: Aswin Chandramouleeswaran <aswin@hp.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1378693159-8747-8-git-send-email-davidlohr@hp.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf')
-rw-r--r--tools/perf/Documentation/perf-lock.txt2
-rw-r--r--tools/perf/builtin-lock.c10
2 files changed, 10 insertions, 2 deletions
diff --git a/tools/perf/Documentation/perf-lock.txt b/tools/perf/Documentation/perf-lock.txt
index c7f5f55634ac..ab25be28c9dc 100644
--- a/tools/perf/Documentation/perf-lock.txt
+++ b/tools/perf/Documentation/perf-lock.txt
@@ -48,7 +48,7 @@ REPORT OPTIONS
-k::
--key=<value>::
Sorting key. Possible values: acquired (default), contended,
- wait_total, wait_max, wait_min.
+ avg_wait, wait_total, wait_max, wait_min.
INFO OPTIONS
------------
diff --git a/tools/perf/builtin-lock.c b/tools/perf/builtin-lock.c
index 972310cbeb63..6a9076f165f4 100644
--- a/tools/perf/builtin-lock.c
+++ b/tools/perf/builtin-lock.c
@@ -56,7 +56,9 @@ struct lock_stat {
unsigned int nr_readlock;
unsigned int nr_trylock;
+
/* these times are in nano sec. */
+ u64 avg_wait_time;
u64 wait_time_total;
u64 wait_time_min;
u64 wait_time_max;
@@ -208,6 +210,7 @@ static struct thread_stat *thread_stat_findnew_first(u32 tid)
SINGLE_KEY(nr_acquired)
SINGLE_KEY(nr_contended)
+SINGLE_KEY(avg_wait_time)
SINGLE_KEY(wait_time_total)
SINGLE_KEY(wait_time_max)
@@ -244,6 +247,7 @@ static struct rb_root result; /* place to store sorted data */
struct lock_key keys[] = {
DEF_KEY_LOCK(acquired, nr_acquired),
DEF_KEY_LOCK(contended, nr_contended),
+ DEF_KEY_LOCK(avg_wait, avg_wait_time),
DEF_KEY_LOCK(wait_total, wait_time_total),
DEF_KEY_LOCK(wait_min, wait_time_min),
DEF_KEY_LOCK(wait_max, wait_time_max),
@@ -516,6 +520,7 @@ static int report_lock_acquired_event(struct perf_evsel *evsel,
seq->state = SEQ_STATE_ACQUIRED;
ls->nr_acquired++;
+ ls->avg_wait_time = ls->nr_contended ? ls->wait_time_total/ls->nr_contended : 0;
seq->prev_event_time = sample->time;
end:
return 0;
@@ -570,6 +575,7 @@ static int report_lock_contended_event(struct perf_evsel *evsel,
seq->state = SEQ_STATE_CONTENDED;
ls->nr_contended++;
+ ls->avg_wait_time = ls->wait_time_total/ls->nr_contended;
seq->prev_event_time = sample->time;
end:
return 0;
@@ -703,6 +709,7 @@ static void print_result(void)
pr_info("%10s ", "acquired");
pr_info("%10s ", "contended");
+ pr_info("%15s ", "avg wait (ns)");
pr_info("%15s ", "total wait (ns)");
pr_info("%15s ", "max wait (ns)");
pr_info("%15s ", "min wait (ns)");
@@ -734,6 +741,7 @@ static void print_result(void)
pr_info("%10u ", st->nr_acquired);
pr_info("%10u ", st->nr_contended);
+ pr_info("%15" PRIu64 " ", st->avg_wait_time);
pr_info("%15" PRIu64 " ", st->wait_time_total);
pr_info("%15" PRIu64 " ", st->wait_time_max);
pr_info("%15" PRIu64 " ", st->wait_time_min == ULLONG_MAX ?
@@ -940,7 +948,7 @@ int cmd_lock(int argc, const char **argv, const char *prefix __maybe_unused)
};
const struct option report_options[] = {
OPT_STRING('k', "key", &sort_key, "acquired",
- "key for sorting (acquired / contended / wait_total / wait_max / wait_min)"),
+ "key for sorting (acquired / contended / avg_wait / wait_total / wait_max / wait_min)"),
/* TODO: type */
OPT_END()
};