From 4cb93446c587d56e2a54f4f83113daba2c0b6dee Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Wed, 27 Apr 2016 10:16:24 -0300 Subject: 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 Cc: Brendan Gregg Cc: David Ahern Cc: Frederic Weisbecker Cc: Jiri Olsa Cc: Milian Wolff Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-yjqsd30nnkogvj5oyx9ghir9@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-script.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'tools/perf/builtin-script.c') diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c index f43b0c6f88f4..efca81679bb3 100644 --- a/tools/perf/builtin-script.c +++ b/tools/perf/builtin-script.c @@ -2031,7 +2031,7 @@ int cmd_script(int argc, const char **argv, const char *prefix __maybe_unused) OPT_UINTEGER(0, "max-stack", &scripting_max_stack, "Set the maximum stack depth when parsing the callchain, " "anything beyond the specified depth will be ignored. " - "Default: " __stringify(PERF_MAX_STACK_DEPTH)), + "Default: kernel.perf_event_max_stack or " __stringify(PERF_MAX_STACK_DEPTH)), OPT_BOOLEAN('I', "show-info", &show_full_info, "display extended information from perf.data file"), OPT_BOOLEAN('\0', "show-kernel-path", &symbol_conf.show_kernel_path, @@ -2067,6 +2067,8 @@ int cmd_script(int argc, const char **argv, const char *prefix __maybe_unused) NULL }; + scripting_max_stack = sysctl_perf_event_max_stack; + setup_scripting(); argc = parse_options_subcommand(argc, argv, options, script_subcommands, script_usage, -- cgit v1.2.3