Em Wed, Jul 03, 2019 at 10:09:49AM +0200, Jiri Olsa escreveu: > Konstantin reported problem with default perf record command, > which fails on some AMD servers, because of the default maximum > precise config. > > The current fallback mechanism counts on getting ENOTSUP errno for > precise_ip fails, but that's not the case on some AMD servers. > > We can fix this by removing the errno check completely, because the > precise_ip fallback is separated. We can just try (if requested by > evsel->precise_max) all possible precise_ip, and if one succeeds we > win, if not, we continue with standard fallback.
Thanks, applied. Simple test shows that behaviour continues the same on x86_64. - Arnaldo > Reported-by: Konstantin Kharlamov <[email protected]> > Cc: Quentin Monnet <[email protected]> > Cc: Kim Phillips <[email protected]> > Cc: Andi Kleen <[email protected]> > Signed-off-by: Jiri Olsa <[email protected]> > --- > tools/perf/util/evsel.c | 10 ++-------- > 1 file changed, 2 insertions(+), 8 deletions(-) > > diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c > index 5ab31a4a658d..7fb4ae82f34c 100644 > --- a/tools/perf/util/evsel.c > +++ b/tools/perf/util/evsel.c > @@ -1800,14 +1800,8 @@ static int perf_event_open(struct perf_evsel *evsel, > if (fd >= 0) > break; > > - /* > - * Do quick precise_ip fallback if: > - * - there is precise_ip set in perf_event_attr > - * - maximum precise is requested > - * - sys_perf_event_open failed with ENOTSUP error, > - * which is associated with wrong precise_ip > - */ > - if (!precise_ip || !evsel->precise_max || (errno != ENOTSUP)) > + /* Do not try less precise if not requested. */ > + if (!evsel->precise_max) > break; > > /* > -- > 2.21.0 -- - Arnaldo
