perf top: Access hists->lock only if needed

The perf_top__record_precise_ip() releases and regrabs the
he->hists->lock because it can sleep if there's an error.  But it should
be done conditionally as it slows down the fast path.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1449802616-16170-2-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Namhyung Kim 2015-12-11 11:56:54 +09:00 committed by Arnaldo Carvalho de Melo
parent 64226bcf64
commit 151ee834cc

View file

@ -194,21 +194,23 @@ static void perf_top__record_precise_ip(struct perf_top *top,
pthread_mutex_unlock(&notes->lock);
/*
* This function is now called with he->hists->lock held.
* Release it before going to sleep.
*/
pthread_mutex_unlock(&he->hists->lock);
if (unlikely(err)) {
/*
* This function is now called with he->hists->lock held.
* Release it before going to sleep.
*/
pthread_mutex_unlock(&he->hists->lock);
if (err == -ERANGE && !he->ms.map->erange_warned)
ui__warn_map_erange(he->ms.map, sym, ip);
else if (err == -ENOMEM) {
pr_err("Not enough memory for annotating '%s' symbol!\n",
sym->name);
sleep(1);
if (err == -ERANGE && !he->ms.map->erange_warned)
ui__warn_map_erange(he->ms.map, sym, ip);
else if (err == -ENOMEM) {
pr_err("Not enough memory for annotating '%s' symbol!\n",
sym->name);
sleep(1);
}
pthread_mutex_lock(&he->hists->lock);
}
pthread_mutex_lock(&he->hists->lock);
}
static void perf_top__show_details(struct perf_top *top)