6.12-stable review patch. If anyone has any objections, please let me know.
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From: Xu Yang xu.yang_2@nxp.com
commit 4a159e6049f319bef6f9e6d2ccdd322f57d24830 upstream.
When do perf stat on sys metric, perf tool output nothing now:
$ perf stat -a -M imx95_ddr_read.all -I 1000 $
This command runs on an arm64 machine and the Soc has one DDR hw pmu except one armv8_cortex_a55 pmu. Their maps show as follows:
const struct pmu_events_map pmu_events_map[] = { { .arch = "arm64", .cpuid = "0x00000000410fd050", .event_table = { .pmus = pmu_events__arm_cortex_a55, .num_pmus = ARRAY_SIZE(pmu_events__arm_cortex_a55) }, .metric_table = { .pmus = NULL, .num_pmus = 0 } },
static const struct pmu_sys_events pmu_sys_event_tables[] = { { .event_table = { .pmus = pmu_events__freescale_imx95_sys, .num_pmus = ARRAY_SIZE(pmu_events__freescale_imx95_sys) }, .metric_table = { .pmus = pmu_metrics__freescale_imx95_sys, .num_pmus = ARRAY_SIZE(pmu_metrics__freescale_imx95_sys) }, .name = "pmu_events__freescale_imx95_sys", },
Currently, pmu_metrics_table__find() will return NULL when only do perf stat on sys metric. Then parse_groups() will never be called to parse sys metric_name, finally perf tool will exit directly. This should be a common problem.
To fix the issue, this will keep the logic before commit f20c15d13f01 ("perf pmu-events: Remember the perf_events_map for a PMU") to return a empty metric table rather than a NULL pointer.
This should be fine since the removed part just check if the table match provided metric_name. Without these code, the code in parse_groups() will also check the validity of metrci_name too.
Fixes: f20c15d13f017d4b ("perf pmu-events: Remember the perf_events_map for a PMU") Reviewed-by: James Clark james.clark@linaro.org Signed-off-by: Xu Yang xu.yang_2@nxp.com Tested-by: Xu Yang xu.yang_2@nxp.com Acked-by: Ian Rogers irogers@google.com Cc: Adrian Hunter adrian.hunter@intel.com Cc: Albert Ou aou@eecs.berkeley.edu Cc: Alexander Shishkin alexander.shishkin@linux.intel.com Cc: Alexandre Ghiti alexghiti@rivosinc.com Cc: Athira Rajeev atrajeev@linux.vnet.ibm.com Cc: Benjamin Gray bgray@linux.ibm.com Cc: Ben Zong-You Xie ben717@andestech.com Cc: Bibo Mao maobibo@loongson.cn Cc: Clément Le Goffic clement.legoffic@foss.st.com Cc: Dima Kogan dima@secretsauce.net Cc: Dr. David Alan Gilbert linux@treblig.org Cc: Huacai Chen chenhuacai@kernel.org Cc: Ingo Molnar mingo@redhat.com Cc: Jiri Olsa jolsa@kernel.org Cc: John Garry john.g.garry@oracle.com Cc: Kan Liang kan.liang@linux.intel.com Cc: Leo Yan leo.yan@linux.dev Cc: Mark Rutland mark.rutland@arm.com Cc: Masami Hiramatsu mhiramat@kernel.org Cc: Mike Leach mike.leach@linaro.org Cc: Namhyung Kim namhyung@kernel.org Cc: Palmer Dabbelt palmer@dabbelt.com Cc: Paul Walmsley paul.walmsley@sifive.com Cc: Peter Zijlstra peterz@infradead.org Cc: Ravi Bangoria ravi.bangoria@amd.com Cc: Sandipan Das sandipan.das@amd.com Cc: Will Deacon will@kernel.org Cc: Yicong Yang yangyicong@hisilicon.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-riscv@lists.infradead.org Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20241107162035.52206-2-irogers@google.com Signed-off-by: Ian Rogers irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- tools/perf/pmu-events/empty-pmu-events.c | 12 +----------- tools/perf/pmu-events/jevents.py | 12 +----------- 2 files changed, 2 insertions(+), 22 deletions(-)
--- a/tools/perf/pmu-events/empty-pmu-events.c +++ b/tools/perf/pmu-events/empty-pmu-events.c @@ -539,17 +539,7 @@ const struct pmu_metrics_table *perf_pmu if (!map) return NULL;
- if (!pmu) - return &map->metric_table; - - for (size_t i = 0; i < map->metric_table.num_pmus; i++) { - const struct pmu_table_entry *table_pmu = &map->metric_table.pmus[i]; - const char *pmu_name = &big_c_string[table_pmu->pmu_name.offset]; - - if (pmu__name_match(pmu, pmu_name)) - return &map->metric_table; - } - return NULL; + return &map->metric_table; }
const struct pmu_events_table *find_core_events_table(const char *arch, const char *cpuid) --- a/tools/perf/pmu-events/jevents.py +++ b/tools/perf/pmu-events/jevents.py @@ -1089,17 +1089,7 @@ const struct pmu_metrics_table *perf_pmu if (!map) return NULL;
- if (!pmu) - return &map->metric_table; - - for (size_t i = 0; i < map->metric_table.num_pmus; i++) { - const struct pmu_table_entry *table_pmu = &map->metric_table.pmus[i]; - const char *pmu_name = &big_c_string[table_pmu->pmu_name.offset]; - - if (pmu__name_match(pmu, pmu_name)) - return &map->metric_table; - } - return NULL; + return &map->metric_table; }
const struct pmu_events_table *find_core_events_table(const char *arch, const char *cpuid)