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perf lock: Account for lock average wait time

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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>
This commit is contained in:
Davidlohr Bueso 2013-09-08 19:19:19 -07:00 committed by Arnaldo Carvalho de Melo
parent 60a25cbc4a
commit f37376cd72
2 changed files with 10 additions and 2 deletions
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2
tools/perf/Documentation/perf-lock.txt
View File

@ -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
------------

10
tools/perf/builtin-lock.c
View File

@ -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()
};