Commit 9f94c7f9 authored Jun 20, 2019 by Kyle Meyer Committed by Arnaldo Carvalho de Melo Jun 25, 2019

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>

parent eb5d8544

tools/perf/perf.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -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;

tools/perf/util/header.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -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)

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