lkml.org 
[lkml]   [2019]   [Jul]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH AUTOSEL 4.9 55/73] perf tools: Increase MAX_NR_CPUS and MAX_CACHES
    Date
    From: Kyle Meyer <kyle.meyer@hpe.com>

    [ Upstream commit 9f94c7f947e919c343b30f080285af53d0fa9902 ]

    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>
    Signed-off-by: Sasha Levin <sashal@kernel.org>
    ---
    tools/perf/perf.h | 2 +-
    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 8f8d895d5b74..3b9d56125ee2 100644
    --- a/tools/perf/perf.h
    +++ b/tools/perf/perf.h
    @@ -23,7 +23,7 @@ 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 de9b369d2d2e..283148104ffb 100644
    --- a/tools/perf/util/header.c
    +++ b/tools/perf/util/header.c
    @@ -1008,7 +1008,7 @@ 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(int fd, struct perf_header *h __maybe_unused,
    struct perf_evlist *evlist __maybe_unused)
    --
    2.20.1
    \
     
     \ /
      Last update: 2019-07-15 17:45    [W:4.896 / U:0.228 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site