Messages in this thread | | | Subject | Re: [PATCH v1] perf tools: Fix pattern matching for same substring used in different pmu type | From | "Jin, Yao" <> | Date | Fri, 11 Jun 2021 10:54:38 +0800 |
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And, though this patch is to fix the uncore_imc/uncore_imc_free_running mismatching issue. We are also surprised to see it can solve another hybrid PMU issue on Alderlake.
On Alderlake,
# ./perf stat -e cpu/event=0xc2,umask=0x2/ true
Performance counter stats for 'true':
702,246 cpu_core/event=0xc2,umask=0x2/ <not counted> cpu_atom/event=0xc2,umask=0x2/
It should error out with the wrong PMU rather than using 'cpu_core' and'cpu_atom' instead.
This is still the pattern matching issue. The pattern is "cpu*". Both "cpu_core" and "cpu_atom" can match the pattern "cpu*", so the parser wrongly thinks they are the same PMU type.
Now with this patch,
# ./perf stat -e cpu/cpu-cycles/ true event syntax error: 'cpu/cpu-cycles/' \___ Cannot find PMU `cpu'. Missing kernel support? Run 'perf list' for a list of valid events
Thanks Jin Yao
On 6/9/2021 12:57 PM, Jin Yao wrote: > Some different pmu types may have same substring. For example, > on Icelake server, we have pmu types "uncore_imc" and > "uncore_imc_free_running". Both pmu types have substring "uncore_imc". > But the parser would wrongly think they are the same pmu type. > > We enable an imc event, > perf stat -e uncore_imc/event=0xe3/ -a -- sleep 1 > > Perf actually expands the event to: > uncore_imc_0/event=0xe3/ > uncore_imc_1/event=0xe3/ > uncore_imc_2/event=0xe3/ > uncore_imc_3/event=0xe3/ > uncore_imc_4/event=0xe3/ > uncore_imc_5/event=0xe3/ > uncore_imc_6/event=0xe3/ > uncore_imc_7/event=0xe3/ > uncore_imc_free_running_0/event=0xe3/ > uncore_imc_free_running_1/event=0xe3/ > uncore_imc_free_running_3/event=0xe3/ > uncore_imc_free_running_4/event=0xe3/ > > That's because the "uncore_imc_free_running" matches the > pattern "uncore_imc*". > > Now we check that the last characters of pmu name is > '_<digit>'. > > Fixes: b2b9d3a3f021 ("perf pmu: Support wildcards on pmu name in dynamic pmu events") > Signed-off-by: Jin Yao <yao.jin@linux.intel.com> > --- > tools/perf/util/parse-events.y | 2 ++ > tools/perf/util/pmu.c | 25 ++++++++++++++++++++++++- > tools/perf/util/pmu.h | 1 + > 3 files changed, 27 insertions(+), 1 deletion(-) > > diff --git a/tools/perf/util/parse-events.y b/tools/perf/util/parse-events.y > index aba12a4d488e..7a694c7f7f1a 100644 > --- a/tools/perf/util/parse-events.y > +++ b/tools/perf/util/parse-events.y > @@ -317,6 +317,8 @@ event_pmu_name opt_pmu_config > strncmp($1, "uncore_", 7)) > name += 7; > if (!fnmatch(pattern, name, 0)) { > + if (!perf_pmu__valid_suffix($1, name)) > + continue; > if (parse_events_copy_term_list(orig_terms, &terms)) > CLEANUP_YYABORT; > if (!parse_events_add_pmu(_parse_state, list, pmu->name, terms, true, false)) > diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c > index 88c8ecdc60b0..78af01959830 100644 > --- a/tools/perf/util/pmu.c > +++ b/tools/perf/util/pmu.c > @@ -3,6 +3,7 @@ > #include <linux/compiler.h> > #include <linux/string.h> > #include <linux/zalloc.h> > +#include <linux/ctype.h> > #include <subcmd/pager.h> > #include <sys/types.h> > #include <errno.h> > @@ -768,7 +769,7 @@ bool pmu_uncore_alias_match(const char *pmu_name, const char *name) > */ > for (; tok; name += strlen(tok), tok = strtok_r(NULL, ",", &tmp)) { > name = strstr(name, tok); > - if (!name) { > + if (!name || !perf_pmu__valid_suffix(tok, (char *)name)) { > res = false; > goto out; > } > @@ -1872,3 +1873,25 @@ bool perf_pmu__has_hybrid(void) > > return !list_empty(&perf_pmu__hybrid_pmus); > } > + > +bool perf_pmu__valid_suffix(char *tok, char *pmu_name) > +{ > + char *p; > + > + /* > + * The pmu_name has substring tok. If the format of > + * pmu_name is <tok> or <tok>_<digit>, return true. > + */ > + p = pmu_name + strlen(tok); > + if (*p == 0) > + return true; > + > + if (*p != '_') > + return false; > + > + ++p; > + if (*p == 0 || !isdigit(*p)) > + return false; > + > + return true; > +} > diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h > index a790ef758171..ebfd2b71532b 100644 > --- a/tools/perf/util/pmu.h > +++ b/tools/perf/util/pmu.h > @@ -133,5 +133,6 @@ void perf_pmu__warn_invalid_config(struct perf_pmu *pmu, __u64 config, > char *name); > > bool perf_pmu__has_hybrid(void); > +bool perf_pmu__valid_suffix(char *tok, char *pmu_name); > > #endif /* __PMU_H */ >
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