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....@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 <jo...@redhat.com>
thanks,
jirka
> ---
> 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
>
