From 029c75e5cf166f9c04744d81c798f54a44a8417c Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Thu, 17 May 2018 16:31:32 -0300 Subject: [PATCH] perf tools: No need to unconditionally read the max_stack sysctls Let tools that need to have those variables with the sysctl current values use a function that will read them. Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: https://lkml.kernel.org/n/tip-1ljj3oeo5kpt2n1icfd9vowe@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-top.c | 2 +- tools/perf/builtin-trace.c | 2 +- tools/perf/perf.c | 7 ------- tools/perf/util/evsel.c | 2 +- tools/perf/util/util.c | 13 +++++++++++++ tools/perf/util/util.h | 2 ++ 6 files changed, 18 insertions(+), 10 deletions(-) diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c index 3c061c57afb6..7a349fcd3864 100644 --- a/tools/perf/builtin-top.c +++ b/tools/perf/builtin-top.c @@ -1264,7 +1264,7 @@ int cmd_top(int argc, const char **argv) .proc_map_timeout = 500, .overwrite = 1, }, - .max_stack = sysctl_perf_event_max_stack, + .max_stack = sysctl__max_stack(), .sym_pcnt_filter = 5, .nr_threads_synthesize = UINT_MAX, }; diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c index c7effcfc40ed..560aed7da36a 100644 --- a/tools/perf/builtin-trace.c +++ b/tools/perf/builtin-trace.c @@ -3162,7 +3162,7 @@ int cmd_trace(int argc, const char **argv) mmap_pages_user_set = false; if (trace.max_stack == UINT_MAX) { - trace.max_stack = input_name ? PERF_MAX_STACK_DEPTH : sysctl_perf_event_max_stack; + trace.max_stack = input_name ? PERF_MAX_STACK_DEPTH : sysctl__max_stack(); max_stack_user_set = false; } diff --git a/tools/perf/perf.c b/tools/perf/perf.c index cefd8f74630c..51c81509a315 100644 --- a/tools/perf/perf.c +++ b/tools/perf/perf.c @@ -426,7 +426,6 @@ int main(int argc, const char **argv) int err; const char *cmd; char sbuf[STRERR_BUFSIZE]; - int value; /* libsubcmd init */ exec_cmd_init("perf", PREFIX, PERF_EXEC_PATH, EXEC_PATH_ENVIRONMENT); @@ -435,12 +434,6 @@ int main(int argc, const char **argv) /* The page_size is placed in util object. */ page_size = sysconf(_SC_PAGE_SIZE); - if (sysctl__read_int("kernel/perf_event_max_stack", &value) == 0) - sysctl_perf_event_max_stack = value; - - if (sysctl__read_int("kernel/perf_event_max_contexts_per_stack", &value) == 0) - sysctl_perf_event_max_contexts_per_stack = value; - cmd = extract_argv0_path(argv[0]); if (!cmd) cmd = "perf-help"; diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index 4cd2cf93f726..150db5ed7400 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -2862,7 +2862,7 @@ int perf_evsel__open_strerror(struct perf_evsel *evsel, struct target *target, return scnprintf(msg, size, "Not enough memory to setup event with callchain.\n" "Hint: Try tweaking /proc/sys/kernel/perf_event_max_stack\n" - "Hint: Current value: %d", sysctl_perf_event_max_stack); + "Hint: Current value: %d", sysctl__max_stack()); break; case ENODEV: if (target->cpu_list) diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c index 99ab52165680..eac5b858a371 100644 --- a/tools/perf/util/util.c +++ b/tools/perf/util/util.c @@ -62,6 +62,19 @@ int cacheline_size(void) int sysctl_perf_event_max_stack = PERF_MAX_STACK_DEPTH; int sysctl_perf_event_max_contexts_per_stack = PERF_MAX_CONTEXTS_PER_STACK; +int sysctl__max_stack(void) +{ + int value; + + if (sysctl__read_int("kernel/perf_event_max_stack", &value) == 0) + sysctl_perf_event_max_stack = value; + + if (sysctl__read_int("kernel/perf_event_max_contexts_per_stack", &value) == 0) + sysctl_perf_event_max_contexts_per_stack = value; + + return sysctl_perf_event_max_stack; +} + bool test_attr__enabled; bool perf_host = true; diff --git a/tools/perf/util/util.h b/tools/perf/util/util.h index 74d21dfe0d29..dc58254a2b69 100644 --- a/tools/perf/util/util.h +++ b/tools/perf/util/util.h @@ -45,6 +45,8 @@ int hex2u64(const char *ptr, u64 *val); extern unsigned int page_size; int __pure cacheline_size(void); +int sysctl__max_stack(void); + int fetch_kernel_version(unsigned int *puint, char *str, size_t str_sz); #define KVER_VERSION(x) (((x) >> 16) & 0xff)