Re: [PATCH v1] perf jevents: Use "default_core" for events with no Unit

From: Ian Rogers
Date: Wed Aug 30 2023 - 14:33:11 EST


On Wed, Aug 30, 2023 at 2:00 AM James Clark <james.clark@xxxxxxx> wrote:
>
>
>
> On 26/08/2023 07:22, Ian Rogers wrote:
> > The json Unit field encodes the name of the PMU to match the events
> > to. When no name is given it has meant the "cpu" core PMU except for
> > tests. On ARM, Intel hybrid and s390 the core PMU is named differently
> > which means that using "cpu" for this case causes the events not to
> > get matched to the PMU. Introduce a new "default_core" string for this
> > case and in the pmu__name_match force all core PMUs to match this
> > name.
> >
> > Reported-by: Thomas Richter <tmricht@xxxxxxxxxxxxx>
> > Reported-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
> > Fixes: 2e255b4f9f41 ("perf jevents: Group events by PMU")
> > Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
>
> Hi Ian,
>
> Running 'perf list' with this change I get "munmap_chunk(): invalid
> pointer". It's probably related to an earlier change though.
>
> Here's the stack:
>
> Program received signal SIGABRT, Aborted.
> __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50
> 50 ../sysdeps/unix/sysv/linux/raise.c: No such file or directory.
> (gdb) bt
> #0 __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50
> #1 0x0000fffff70adaac in __GI_abort () at abort.c:79
> #2 0x0000fffff70faf40 in __libc_message (action=action@entry=do_abort, fmt=fmt@entry=0xfffff71bc518 "%s\n")
> at ../sysdeps/posix/libc_fatal.c:155
> #3 0x0000fffff7102344 in malloc_printerr (str=str@entry=0xfffff71b7ae0 "munmap_chunk(): invalid pointer") at malloc.c:5347
> #4 0x0000fffff7102644 in munmap_chunk (p=<optimized out>) at malloc.c:2830
> #5 0x0000aaaaaadc727c in __zfree (ptr=0xaaaaaaf89db0) at ../../lib/zalloc.c:13
> #6 0x0000aaaaaacbbbcc in assign_str (name=0xaaaaaae878c2 "l1d_cache_refill", field=0xaaaaaae4fb78 "value", old_str=0xaaaaaaf89db0,
> new_str=0xaaaaaae878f7 "event=0x3") at util/pmu.c:454
> #7 0x0000aaaaaacbbdf4 in update_alias (pe=0xffffffffd450, table=0xaaaaaaf43870 <pmu_events_map+592>, vdata=0xffffffffd598)
> at util/pmu.c:490
> #8 0x0000aaaaaadbc37c in pmu_events_table__find_event_pmu (table=0xaaaaaaf43870 <pmu_events_map+592>,
> pmu=0xaaaaaaf43400 <pmu_events.arm_neoverse_n1>, name=0xaaaaaaf900b3 "l1d_cache_refill", fn=0xaaaaaacbbcc0 <update_alias>,
> data=0xffffffffd598) at pmu-events/pmu-events.c:5359
> #9 0x0000aaaaaadbc598 in pmu_events_table__find_event (table=0xaaaaaaf43870 <pmu_events_map+592>, pmu=0xaaaaaaf8fcd0,
> name=0xaaaaaaf900b3 "l1d_cache_refill", fn=0xaaaaaacbbcc0 <update_alias>, data=0xffffffffd598)
> at pmu-events/pmu-events.c:5398
> #10 0x0000aaaaaacbc1f0 in perf_pmu__new_alias (pmu=0xaaaaaaf8fcd0, name=0xaaaaaaf900b3 "l1d_cache_refill", desc=0x0, val=0x0,
> val_fd=0xaaaaaaf8a2e0, pe=0x0) at util/pmu.c:569
> #11 0x0000aaaaaacbc710 in pmu_aliases_parse (pmu=0xaaaaaaf8fcd0) at util/pmu.c:673
> #12 0x0000aaaaaacbf168 in perf_pmu__num_events (pmu=0xaaaaaaf8fcd0) at util/pmu.c:1633
> #13 0x0000aaaaaacc1e00 in perf_pmus__print_pmu_events (print_cb=0xffffffffe878, print_state=0xffffffffe898) at util/pmus.c:359
> #14 0x0000aaaaaac53810 in print_events (print_cb=0xffffffffe878, print_state=0xffffffffe898) at util/print-events.c:407
> #15 0x0000aaaaaab1cc30 in cmd_list (argc=0, argv=0xfffffffff0c0) at builtin-list.c:524
> #16 0x0000aaaaaac106f0 in run_builtin (p=0xaaaaaaf59580 <commands+240>, argc=2, argv=0xfffffffff0c0) at perf.c:322
> #17 0x0000aaaaaac109a4 in handle_internal_command (argc=2, argv=0xfffffffff0c0) at perf.c:375
> #18 0x0000aaaaaac10b5c in run_argv (argcp=0xffffffffeebc, argv=0xffffffffeeb0) at perf.c:419
> #19 0x0000aaaaaac10e84 in main (argc=2, argv=0xfffffffff0c0) at perf.c:535

Hi James,

Could you try adding:
https://lore.kernel.org/lkml/20230830000545.1638964-1-irogers@xxxxxxxxxx/
which I believe fixes the problem.

Thanks,
Ian

> > ---
> > tools/perf/pmu-events/jevents.py | 2 +-
> > tools/perf/tests/pmu-events.c | 19 ++++++++++---------
> > tools/perf/util/pmu.c | 7 ++++++-
> > 3 files changed, 17 insertions(+), 11 deletions(-)
> >
> > diff --git a/tools/perf/pmu-events/jevents.py b/tools/perf/pmu-events/jevents.py
> > index 712f80d7d071..a7e88332276d 100755
> > --- a/tools/perf/pmu-events/jevents.py
> > +++ b/tools/perf/pmu-events/jevents.py
> > @@ -266,7 +266,7 @@ class JsonEvent:
> > def unit_to_pmu(unit: str) -> Optional[str]:
> > """Convert a JSON Unit to Linux PMU name."""
> > if not unit:
> > - return 'cpu'
> > + return 'default_core'
> > # Comment brought over from jevents.c:
> > # it's not realistic to keep adding these, we need something more scalable ...
> > table = {
> > diff --git a/tools/perf/tests/pmu-events.c b/tools/perf/tests/pmu-events.c
> > index ce4da9b1d115..f5321fbdee79 100644
> > --- a/tools/perf/tests/pmu-events.c
> > +++ b/tools/perf/tests/pmu-events.c
> > @@ -44,7 +44,7 @@ struct perf_pmu_test_pmu {
> >
> > static const struct perf_pmu_test_event bp_l1_btb_correct = {
> > .event = {
> > - .pmu = "cpu",
> > + .pmu = "default_core",
> > .name = "bp_l1_btb_correct",
> > .event = "event=0x8a",
> > .desc = "L1 BTB Correction",
> > @@ -56,7 +56,7 @@ static const struct perf_pmu_test_event bp_l1_btb_correct = {
> >
> > static const struct perf_pmu_test_event bp_l2_btb_correct = {
> > .event = {
> > - .pmu = "cpu",
> > + .pmu = "default_core",
> > .name = "bp_l2_btb_correct",
> > .event = "event=0x8b",
> > .desc = "L2 BTB Correction",
> > @@ -68,7 +68,7 @@ static const struct perf_pmu_test_event bp_l2_btb_correct = {
> >
> > static const struct perf_pmu_test_event segment_reg_loads_any = {
> > .event = {
> > - .pmu = "cpu",
> > + .pmu = "default_core",
> > .name = "segment_reg_loads.any",
> > .event = "event=0x6,period=200000,umask=0x80",
> > .desc = "Number of segment register loads",
> > @@ -80,7 +80,7 @@ static const struct perf_pmu_test_event segment_reg_loads_any = {
> >
> > static const struct perf_pmu_test_event dispatch_blocked_any = {
> > .event = {
> > - .pmu = "cpu",
> > + .pmu = "default_core",
> > .name = "dispatch_blocked.any",
> > .event = "event=0x9,period=200000,umask=0x20",
> > .desc = "Memory cluster signals to block micro-op dispatch for any reason",
> > @@ -92,7 +92,7 @@ static const struct perf_pmu_test_event dispatch_blocked_any = {
> >
> > static const struct perf_pmu_test_event eist_trans = {
> > .event = {
> > - .pmu = "cpu",
> > + .pmu = "default_core",
> > .name = "eist_trans",
> > .event = "event=0x3a,period=200000,umask=0x0",
> > .desc = "Number of Enhanced Intel SpeedStep(R) Technology (EIST) transitions",
> > @@ -104,7 +104,7 @@ static const struct perf_pmu_test_event eist_trans = {
> >
> > static const struct perf_pmu_test_event l3_cache_rd = {
> > .event = {
> > - .pmu = "cpu",
> > + .pmu = "default_core",
> > .name = "l3_cache_rd",
> > .event = "event=0x40",
> > .desc = "L3 cache access, read",
> > @@ -391,8 +391,8 @@ static int compare_alias_to_test_event(struct pmu_event_info *alias,
> > return -1;
> > }
> >
> > -
> > - if (!is_same(alias->pmu_name, test_event->event.pmu)) {
> > + if (!is_same(alias->pmu_name, test_event->event.pmu) &&
> > + !is_same(alias->pmu_name, "default_core")) {
> > pr_debug("testing aliases PMU %s: mismatched pmu_name, %s vs %s\n",
> > pmu_name, alias->pmu_name, test_event->event.pmu);
> > return -1;
> > @@ -409,7 +409,7 @@ static int test__pmu_event_table_core_callback(const struct pmu_event *pe,
> > struct perf_pmu_test_event const **test_event_table;
> > bool found = false;
> >
> > - if (strcmp(pe->pmu, "cpu"))
> > + if (strcmp(pe->pmu, "default_core"))
> > test_event_table = &uncore_events[0];
> > else
> > test_event_table = &core_events[0];
> > @@ -543,6 +543,7 @@ static int __test_core_pmu_event_aliases(const char *pmu_name, int *count)
> > INIT_LIST_HEAD(&pmu->caps);
> > INIT_LIST_HEAD(&pmu->list);
> > pmu->name = strdup(pmu_name);
> > + pmu->is_core = true;
> >
> > pmu->events_table = table;
> > pmu_add_cpu_aliases_table(pmu, table);
> > diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
> > index 502fd58c3ea7..cde33e01959a 100644
> > --- a/tools/perf/util/pmu.c
> > +++ b/tools/perf/util/pmu.c
> > @@ -1747,7 +1747,12 @@ int perf_pmu__for_each_event(struct perf_pmu *pmu, bool skip_duplicate_pmus,
> > bool pmu__name_match(const struct perf_pmu *pmu, const char *pmu_name)
> > {
> > return !strcmp(pmu->name, pmu_name) ||
> > - (pmu->is_uncore && pmu_uncore_alias_match(pmu_name, pmu->name));
> > + (pmu->is_uncore && pmu_uncore_alias_match(pmu_name, pmu->name)) ||
> > + /*
> > + * jevents and tests use default_core as a marker for any core
> > + * PMU as the PMU name varies across architectures.
> > + */
> > + (pmu->is_core && !strcmp(pmu_name, "default_core"));
> > }
> >
> > bool perf_pmu__is_software(const struct perf_pmu *pmu)