Messages in this thread | | | Subject | Re: [PATCH 02/14] perf trace: Apply new perf_mmap__read_event() interface | From | "Liang, Kan" <> | Date | Mon, 5 Mar 2018 09:28:27 -0500 |
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On 3/2/2018 6:30 PM, Jiri Olsa wrote: > On Thu, Mar 01, 2018 at 06:08:59PM -0500, kan.liang@linux.intel.com wrote: >> From: Kan Liang <kan.liang@linux.intel.com> >> >> The perf trace still use the legacy interface. >> >> Apply the new perf_mmap__read_event() interface for perf trace. >> >> No functional change. >> >> Signed-off-by: Kan Liang <kan.liang@linux.intel.com> >> --- >> tools/perf/builtin-trace.c | 11 +++++++++-- >> 1 file changed, 9 insertions(+), 2 deletions(-) >> >> diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c >> index e7f1b18..a46644f 100644 >> --- a/tools/perf/builtin-trace.c >> +++ b/tools/perf/builtin-trace.c >> @@ -2472,8 +2472,14 @@ static int trace__run(struct trace *trace, int argc, const char **argv) >> >> for (i = 0; i < evlist->nr_mmaps; i++) { >> union perf_event *event; >> + struct perf_mmap *md; >> + u64 end, start; >> >> - while ((event = perf_evlist__mmap_read(evlist, i)) != NULL) { >> + md = &evlist->mmap[i]; >> + if (perf_mmap__read_init(md, 0, &start, &end) < 0) >> + continue; > > should we break the loop if this returns -EINVAL? >
It only means the ring buffer is broken for current mmaps. For others, the data should still be good. I don't think we should drop them by breaking the loop.
Also, the -EINVAL is only valid for overwrite mode. It is impossible to return -EINVAL in current code.
Thanks, Kan
> jirka > >> + >> + while ((event = perf_mmap__read_event(md, 0, &start, end)) != NULL) { >> struct perf_sample sample; >> >> ++trace->nr_events; >> @@ -2486,7 +2492,7 @@ static int trace__run(struct trace *trace, int argc, const char **argv) >> >> trace__handle_event(trace, event, &sample); >> next_event: >> - perf_evlist__mmap_consume(evlist, i); >> + perf_mmap__consume(md, 0); >> >> if (interrupted) >> goto out_disable; >> @@ -2496,6 +2502,7 @@ static int trace__run(struct trace *trace, int argc, const char **argv) >> draining = true; >> } >> } >> + perf_mmap__read_done(md); >> } >> >> if (trace->nr_events == before) { >> -- >> 2.4.11 >>
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