diff options
| author | Arnaldo Carvalho de Melo <acme@redhat.com> | 2016-04-27 10:16:24 -0300 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2016-04-27 10:29:07 -0300 |
| commit | 4cb93446c587d56e2a54f4f83113daba2c0b6dee (patch) | |
| tree | a251b1d510831dc071eadbbbe3e38a85fe643365 /tools/perf/perf.c | |
| parent | c5dfd78eb79851e278b7973031b9ca363da87a7e (diff) | |
perf tools: Set the maximum allowed stack from /proc/sys/kernel/perf_event_max_stack
There is an upper limit to what tooling considers a valid callchain,
and it was tied to the hardcoded value in the kernel,
PERF_MAX_STACK_DEPTH (127), now that this can be tuned via a sysctl,
make it read it and use that as the upper limit, falling back to
PERF_MAX_STACK_DEPTH for kernels where this sysctl isn't present.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-yjqsd30nnkogvj5oyx9ghir9@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/perf.c')
| -rw-r--r-- | tools/perf/perf.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/tools/perf/perf.c b/tools/perf/perf.c index 7b2df2b46525..83ffe7cd7330 100644 --- a/tools/perf/perf.c +++ b/tools/perf/perf.c @@ -17,6 +17,7 @@ #include <subcmd/parse-options.h> #include "util/bpf-loader.h" #include "util/debug.h" +#include <api/fs/fs.h> #include <api/fs/tracing_path.h> #include <pthread.h> #include <stdlib.h> @@ -533,6 +534,7 @@ int main(int argc, const char **argv) { const char *cmd; char sbuf[STRERR_BUFSIZE]; + int value; /* libsubcmd init */ exec_cmd_init("perf", PREFIX, PERF_EXEC_PATH, EXEC_PATH_ENVIRONMENT); @@ -542,6 +544,9 @@ int main(int argc, const char **argv) page_size = sysconf(_SC_PAGE_SIZE); cacheline_size = sysconf(_SC_LEVEL1_DCACHE_LINESIZE); + if (sysctl__read_int("kernel/perf_event_max_stack", &value) == 0) + sysctl_perf_event_max_stack = value; + cmd = extract_argv0_path(argv[0]); if (!cmd) cmd = "perf-help"; |