On Sat, 11 Jan 2014 17:35:29 +0100, Jiri Olsa wrote: > On Wed, Jan 08, 2014 at 05:46:30PM +0900, Namhyung Kim wrote: >> Reuse hist_entry_iter__add() function to share the similar code with >> perf report. Note that it needs to be called with hists.lock so tweak >> some internal functions not to deadlock or hold the lock too long. >> >> Signed-off-by: Namhyung Kim <[email protected]> >> --- >> tools/perf/builtin-top.c | 75 >> ++++++++++++++++++++++++------------------------ >> 1 file changed, 37 insertions(+), 38 deletions(-) >> >> diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c >> index f0f55e6030cd..cf330c66bed7 100644 >> --- a/tools/perf/builtin-top.c >> +++ b/tools/perf/builtin-top.c >> @@ -186,9 +186,6 @@ static void perf_top__record_precise_ip(struct perf_top >> *top, >> sym = he->ms.sym; >> notes = symbol__annotation(sym); >> >> - if (pthread_mutex_trylock(¬es->lock)) >> - return; >> - >> ip = he->ms.map->map_ip(he->ms.map, ip); >> err = hist_entry__inc_addr_samples(he, counter, ip); >> >> @@ -201,6 +198,8 @@ static void perf_top__record_precise_ip(struct perf_top >> *top, >> sym->name); >> sleep(1); >> } >> + >> + pthread_mutex_lock(¬es->lock); >> } > > locking on function exit.. does not look right ;-)
Yes, it looks weird.. but it's because of the change in locking. After I changed perf top to use the hist_entry_iter, it needed to protect the whole hist_entry_iter__add() by hists->lock so the perf_top__record_precise_ip() should be called with the lock acquired. I might remove the lock in the function completely, but it seemed not good since it goes to sleep with the lock then. So I added the (reverse) unlock/lock dance to avoid it. So yes, I think I need to add a comment to explain this. :) Thanks, Namhyung -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
