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authorArnaldo Carvalho de Melo <acme@redhat.com>2016-04-27 16:16:24 +0300
committerArnaldo Carvalho de Melo <acme@redhat.com>2016-04-27 16:29:07 +0300
commit4cb93446c587d56e2a54f4f83113daba2c0b6dee (patch)
treea251b1d510831dc071eadbbbe3e38a85fe643365 /tools/perf/builtin-top.c
parentc5dfd78eb79851e278b7973031b9ca363da87a7e (diff)
downloadlinux-4cb93446c587d56e2a54f4f83113daba2c0b6dee.tar.xz
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/builtin-top.c')
-rw-r--r--tools/perf/builtin-top.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index c130a11d3a0d..da18517b1d40 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -1103,7 +1103,7 @@ int cmd_top(int argc, const char **argv, const char *prefix __maybe_unused)
},
.proc_map_timeout = 500,
},
- .max_stack = PERF_MAX_STACK_DEPTH,
+ .max_stack = sysctl_perf_event_max_stack,
.sym_pcnt_filter = 5,
};
struct record_opts *opts = &top.record_opts;
@@ -1171,7 +1171,7 @@ int cmd_top(int argc, const char **argv, const char *prefix __maybe_unused)
"Accumulate callchains of children and show total overhead as well"),
OPT_INTEGER(0, "max-stack", &top.max_stack,
"Set the maximum stack depth when parsing the callchain. "
- "Default: " __stringify(PERF_MAX_STACK_DEPTH)),
+ "Default: kernel.perf_event_max_stack or " __stringify(PERF_MAX_STACK_DEPTH)),
OPT_CALLBACK(0, "ignore-callees", NULL, "regex",
"ignore callees of these functions in call graphs",
report_parse_ignore_callees_opt),