Messages in this thread | | | Date | Thu, 30 Apr 2020 13:15:51 +0200 | From | Jiri Olsa <> | Subject | Re: [PATCH] perf parse-events: Use strcmp to compare the PMU name |
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On Thu, Apr 30, 2020 at 09:54:18AM +0100, John Garry wrote: > On 30/04/2020 09:45, Jiri Olsa wrote: > > On Thu, Apr 30, 2020 at 08:36:18AM +0800, Jin Yao wrote: > > > A big uncore event group is split into multiple small groups which > > > only include the uncore events from the same PMU. This has been > > > supported in the commit 3cdc5c2cb924a ("perf parse-events: Handle > > > uncore event aliases in small groups properly"). > > > > > > If the event's PMU name starts to repeat, it must be a new event. > > > That can be used to distinguish the leader from other members. > > > But now it only compares the pointer of pmu_name > > > (leader->pmu_name == evsel->pmu_name). > > > > > > If we use "perf stat -M LLC_MISSES.PCIE_WRITE -a" on cascadelakex, > > > the event list is: > > > > > > evsel->name evsel->pmu_name > > > --------------------------------------------------------------- > > > unc_iio_data_req_of_cpu.mem_write.part0 uncore_iio_4 (as leader) > > > unc_iio_data_req_of_cpu.mem_write.part0 uncore_iio_2 > > > unc_iio_data_req_of_cpu.mem_write.part0 uncore_iio_0 > > > unc_iio_data_req_of_cpu.mem_write.part0 uncore_iio_5 > > > unc_iio_data_req_of_cpu.mem_write.part0 uncore_iio_3 > > > unc_iio_data_req_of_cpu.mem_write.part0 uncore_iio_1 > > > unc_iio_data_req_of_cpu.mem_write.part1 uncore_iio_4 > > > ...... > > > > > > For the event "unc_iio_data_req_of_cpu.mem_write.part1" with > > > "uncore_iio_4", it should be the event from PMU "uncore_iio_4". > > > It's not a new leader for this PMU. > > > > > > But if we use "(leader->pmu_name == evsel->pmu_name)", the check > > > would be failed and the event is stored to leaders[] as a new > > > PMU leader. > > > > > > So this patch uses strcmp to compare the PMU name between events. > > > > > > Fixes: 3cdc5c2cb924a ("perf parse-events: Handle uncore event aliases in small groups properly") > > > Signed-off-by: Jin Yao <yao.jin@linux.intel.com> > > > > looks good, any chance we could have automated test > > for this uncore leader setup logic? like maybe the way > > John did the pmu-events tests? like test will trigger > > only when there's the pmu/events in the system > > > > Acked-by: Jiri Olsa <jolsa@redhat.com> > > > > thanks, > > jirka > > Hi jirka, > > JFYI, this is effectively the same patch as I mentioned to you, which was a > fix for the same WARN: > > https://lore.kernel.org/linux-arm-kernel/1587120084-18990-2-git-send-email-john.garry@huawei.com/ > > but I found that it "fixed" d4953f7ef1a2 ("perf parse-events: Fix 3 use > after frees found with clang ASANutil/parse-events.c"), based on bisect > breakage
hum right.. sorry I did not recalled that, there's also the warn removal in here, could you guys also plz sync on the fixes clauses?
thanks, jirka
> > cheers > > > > > > > > --- > > > tools/perf/util/parse-events.c | 5 ++--- > > > 1 file changed, 2 insertions(+), 3 deletions(-) > > > > > > diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c > > > index 10107747b361..786eddb6a097 100644 > > > --- a/tools/perf/util/parse-events.c > > > +++ b/tools/perf/util/parse-events.c > > > @@ -1629,12 +1629,11 @@ parse_events__set_leader_for_uncore_aliase(char *name, struct list_head *list, > > > * event. That can be used to distinguish the leader from > > > * other members, even they have the same event name. > > > */ > > > - if ((leader != evsel) && (leader->pmu_name == evsel->pmu_name)) { > > > + if ((leader != evsel) && > > > + !strcmp(leader->pmu_name, evsel->pmu_name)) { > > > is_leader = false; > > > continue; > > > } > > > - /* The name is always alias name */ > > > - WARN_ON(strcmp(leader->name, evsel->name)); > > > /* Store the leader event for each PMU */ > > > leaders[nr_pmu++] = (uintptr_t) evsel; > > > -- > > > 2.17.1 > > > > > > > . > > >
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