perf mem record: Check for memory events support

Check if current kernel support available memory events and display the
status within -e  list option:

  $ perf mem record -e list
  ldlat-loads  : available
  ldlat-stores : available

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1456303616-26926-2-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Jiri Olsa 2016-02-24 09:46:42 +01:00 committed by Arnaldo Carvalho de Melo
parent c2b8d8c55c
commit 54fbad54eb
3 changed files with 51 additions and 7 deletions

View File

@ -40,10 +40,11 @@ static int parse_record_events(const struct option *opt,
for (j = 0; j < PERF_MEM_EVENTS__MAX; j++) {
struct perf_mem_event *e = &perf_mem_events[j];
fprintf(stderr, "%-20s%s",
e->tag, verbose ? "" : "\n");
if (verbose)
fprintf(stderr, " [%s]\n", e->name);
fprintf(stderr, "%-13s%-*s%s\n",
e->tag,
verbose ? 25 : 0,
verbose ? e->name : "",
e->supported ? ": available" : "");
}
exit(0);
}
@ -92,6 +93,12 @@ static int __cmd_record(int argc, const char **argv, struct perf_mem *mem)
if (!perf_mem_events[j].record)
continue;
if (!perf_mem_events[j].supported) {
pr_err("failed: event '%s' not supported\n",
perf_mem_events[j].name);
return -1;
}
rec_argv[i++] = "-e";
rec_argv[i++] = perf_mem_events[j].name;
};
@ -355,6 +362,11 @@ int cmd_mem(int argc, const char **argv, const char *prefix __maybe_unused)
NULL
};
if (perf_mem_events__init()) {
pr_err("failed: memory events not supported\n");
return -1;
}
argc = parse_options_subcommand(argc, argv, mem_options, mem_subcommands,
mem_usage, PARSE_OPT_STOP_AT_NON_OPTION);

View File

@ -2,15 +2,20 @@
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <api/fs/fs.h>
#include "mem-events.h"
#include "debug.h"
#define E(t, n) { .tag = t, .name = n }
#define E(t, n, s) { .tag = t, .name = n, .sysfs_name = s }
struct perf_mem_event perf_mem_events[PERF_MEM_EVENTS__MAX] = {
E("ldlat-loads", "cpu/mem-loads,ldlat=30/P"),
E("ldlat-stores", "cpu/mem-stores/P"),
E("ldlat-loads", "cpu/mem-loads,ldlat=30/P", "mem-loads"),
E("ldlat-stores", "cpu/mem-stores/P", "mem-stores"),
};
#undef E
#undef E
@ -49,3 +54,27 @@ int perf_mem_events__parse(const char *str)
pr_err("failed: event '%s' not found, use '-e list' to get list of available events\n", str);
return -1;
}
int perf_mem_events__init(void)
{
const char *mnt = sysfs__mount();
bool found = false;
int j;
if (!mnt)
return -ENOENT;
for (j = 0; j < PERF_MEM_EVENTS__MAX; j++) {
char path[PATH_MAX];
struct perf_mem_event *e = &perf_mem_events[j];
struct stat st;
scnprintf(path, PATH_MAX, "%s/devices/cpu/events/%s",
mnt, e->sysfs_name);
if (!stat(path, &st))
e->supported = found = true;
}
return found ? 0 : -ENOENT;
}

View File

@ -5,8 +5,10 @@
struct perf_mem_event {
bool record;
bool supported;
const char *tag;
const char *name;
const char *sysfs_name;
};
enum {
@ -18,5 +20,6 @@ enum {
extern struct perf_mem_event perf_mem_events[PERF_MEM_EVENTS__MAX];
int perf_mem_events__parse(const char *str);
int perf_mem_events__init(void);
#endif /* __PERF_MEM_EVENTS_H */