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>
This commit is contained in:
Arnaldo Carvalho de Melo 2018-05-17 16:31:32 -03:00
parent 9ac94e31ca
commit 029c75e5cf
6 changed files with 18 additions and 10 deletions

View File

@ -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,
};

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@ -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;
}

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@ -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";

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@ -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)

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@ -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;

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@ -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)