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| author | Kyle Meyer <kyle.meyer@hpe.com> | 2019-06-20 14:36:30 -0500 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2019-06-25 08:47:10 -0300 |
| commit | 9f94c7f947e919c343b30f080285af53d0fa9902 (patch) | |
| tree | cbb287ac88989ea41cc33f6d0bb12d4f5a929cb2 | |
| parent | eb5d854456f5a4ccec6f9681b7196cf056df8cfa (diff) | |
| download | lwn-9f94c7f947e919c343b30f080285af53d0fa9902.tar.gz lwn-9f94c7f947e919c343b30f080285af53d0fa9902.zip | |
perf tools: Increase MAX_NR_CPUS and MAX_CACHES
Attempting to profile 1024 or more CPUs with perf causes two errors:
perf record -a
[ perf record: Woken up X times to write data ]
way too many cpu caches..
[ perf record: Captured and wrote X MB perf.data (X samples) ]
perf report -C 1024
Error: failed to set cpu bitmap
Requested CPU 1024 too large. Consider raising MAX_NR_CPUS
Increasing MAX_NR_CPUS from 1024 to 2048 and redefining MAX_CACHES as
MAX_NR_CPUS * 4 returns normal functionality to perf:
perf record -a
[ perf record: Woken up X times to write data ]
[ perf record: Captured and wrote X MB perf.data (X samples) ]
perf report -C 1024
...
Signed-off-by: Kyle Meyer <kyle.meyer@hpe.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20190620193630.154025-1-meyerk@stormcage.eag.rdlabs.hpecorp.net
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| -rw-r--r-- | tools/perf/perf.h | 2 | ||||
| -rw-r--r-- | tools/perf/util/header.c | 2 |
2 files changed, 2 insertions, 2 deletions
diff --git a/tools/perf/perf.h b/tools/perf/perf.h index 711e009381ec..74d0124d38f3 100644 --- a/tools/perf/perf.h +++ b/tools/perf/perf.h @@ -26,7 +26,7 @@ static inline unsigned long long rdclock(void) } #ifndef MAX_NR_CPUS -#define MAX_NR_CPUS 1024 +#define MAX_NR_CPUS 2048 #endif extern const char *input_name; diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c index 06ddb6618ef3..abc9c2145efe 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -1121,7 +1121,7 @@ static int build_caches(struct cpu_cache_level caches[], u32 size, u32 *cntp) return 0; } -#define MAX_CACHES 2000 +#define MAX_CACHES (MAX_NR_CPUS * 4) static int write_cache(struct feat_fd *ff, struct perf_evlist *evlist __maybe_unused) |