From: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> 3.12-stable review patch. If anyone has any objections, please let me know. =============== commit caa470475d9b59eeff093ae650800d34612c4379 upstream. The original patch introducing this header wrote the number of CPUs available and online in one order and then swapped those values when reading, fix it. Before: # perf record usleep 1 # perf report --header-only | grep 'nrcpus \(online\|avail\)' # nrcpus online : 4 # nrcpus avail : 4 # echo 0 > /sys/devices/system/cpu/cpu2/online # perf record usleep 1 # perf report --header-only | grep 'nrcpus \(online\|avail\)' # nrcpus online : 4 # nrcpus avail : 3 # echo 0 > /sys/devices/system/cpu/cpu1/online # perf record usleep 1 # perf report --header-only | grep 'nrcpus \(online\|avail\)' # nrcpus online : 4 # nrcpus avail : 2 After the fix, bringing back the CPUs online: # perf report --header-only | grep 'nrcpus \(online\|avail\)' # nrcpus online : 2 # nrcpus avail : 4 # echo 1 > /sys/devices/system/cpu/cpu2/online # perf record usleep 1 # perf report --header-only | grep 'nrcpus \(online\|avail\)' # nrcpus online : 3 # nrcpus avail : 4 # echo 1 > /sys/devices/system/cpu/cpu1/online # perf record usleep 1 # perf report --header-only | grep 'nrcpus \(online\|avail\)' # nrcpus online : 4 # nrcpus avail : 4 Acked-by: Namhyung Kim <namhyung@xxxxxxxxxx> Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxx> Cc: David Ahern <dsahern@xxxxxxxxx> Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx> Cc: Jiri Olsa <jolsa@xxxxxxxxxx> Cc: Kan Liang <kan.liang@xxxxxxxxx> Cc: Stephane Eranian <eranian@xxxxxxxxxx> Cc: Wang Nan <wangnan0@xxxxxxxxxx> Fixes: fbe96f29ce4b ("perf tools: Make perf.data more self-descriptive (v8)") Link: http://lkml.kernel.org/r/20150911153323.GP23511@xxxxxxxxxx Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> Signed-off-by: Jiri Slaby <jslaby@xxxxxxx> --- tools/perf/util/header.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c index c3e5a3b817ab..3f82a2f65a65 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -1718,7 +1718,7 @@ static int process_nrcpus(struct perf_file_section *section __maybe_unused, if (ph->needs_swap) nr = bswap_32(nr); - ph->env.nr_cpus_online = nr; + ph->env.nr_cpus_avail = nr; ret = readn(fd, &nr, sizeof(nr)); if (ret != sizeof(nr)) @@ -1727,7 +1727,7 @@ static int process_nrcpus(struct perf_file_section *section __maybe_unused, if (ph->needs_swap) nr = bswap_32(nr); - ph->env.nr_cpus_avail = nr; + ph->env.nr_cpus_online = nr; return 0; } -- 2.6.2 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html