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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>
alistair/sunxi64-5.4-dsi
Kyle Meyer 2019-06-20 14:36:30 -05:00 committed by Arnaldo Carvalho de Melo
parent eb5d854456
commit 9f94c7f947
2 changed files with 2 additions and 2 deletions
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2
tools/perf/perf.h
View File

@ -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;

2
tools/perf/util/header.c
View File

@ -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)