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 <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-1ljj3oeo5kpt2n1icfd9vowe@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 3c061c5..7a349fc 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -1264,7 +1264,7 @@
.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 c7effcf..560aed7 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -3162,7 +3162,7 @@
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 cefd8f7..51c8150 100644
--- a/tools/perf/perf.c
+++ b/tools/perf/perf.c
@@ -426,7 +426,6 @@
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 @@
/* 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 4cd2cf9..150db5ed 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -2862,7 +2862,7 @@
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 99ab521..eac5b85 100644
--- a/tools/perf/util/util.c
+++ b/tools/perf/util/util.c
@@ -62,6 +62,19 @@
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 74d21df..dc58254 100644
--- a/tools/perf/util/util.h
+++ b/tools/perf/util/util.h
@@ -45,6 +45,8 @@
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)