perf bench: Make the mem/memcpy tests more user-friendly
mem-memcpy.c uses perf event system calls to obtain CPU clocks.
And it suddenly dies with BUG_ON() when it running on Linux
doesn't support perf event.
Also fail at calloc() can occur easily when too large
length is passed. Fail of calloc() causes sudden death
with assert().
These behaviours are not friendly. So I fixed the treating of
errors.
Signed-off-by: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1258688237-3797-1-git-send-email-mitake@dcl.info.waseda.ac.jp>
[ v2: improved a few small details ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/tools/perf/bench/mem-memcpy.c b/tools/perf/bench/mem-memcpy.c
index d4f4f98..5165fd1 100644
--- a/tools/perf/bench/mem-memcpy.c
+++ b/tools/perf/bench/mem-memcpy.c
@@ -22,9 +22,10 @@
#define K 1024
-static const char *length_str = "1MB";
-static const char *routine = "default";
-static int use_clock = 0;
+static const char *length_str = "1MB";
+static const char *routine = "default";
+static int use_clock = 0;
+static int clock_fd;
static const struct option options[] = {
OPT_STRING('l', "length", &length_str, "1MB",
@@ -57,17 +58,19 @@
NULL
};
-static int clock_fd;
-
static struct perf_event_attr clock_attr = {
- .type = PERF_TYPE_HARDWARE,
- .config = PERF_COUNT_HW_CPU_CYCLES
+ .type = PERF_TYPE_HARDWARE,
+ .config = PERF_COUNT_HW_CPU_CYCLES
};
static void init_clock(void)
{
clock_fd = sys_perf_event_open(&clock_attr, getpid(), -1, -1, 0);
- BUG_ON(clock_fd < 0);
+
+ if (clock_fd < 0 && errno == ENOSYS)
+ die("No CONFIG_PERF_EVENTS=y kernel support configured?\n");
+ else
+ BUG_ON(clock_fd < 0);
}
static u64 get_clock(void)
@@ -104,7 +107,8 @@
tv_diff.tv_sec = 0;
tv_diff.tv_usec = 0;
length = (size_t)perf_atoll((char *)length_str);
- if ((long long int)length <= 0) {
+
+ if ((s64)length <= 0) {
fprintf(stderr, "Invalid length:%s\n", length_str);
return 1;
}
@@ -124,9 +128,12 @@
}
dst = calloc(length, sizeof(char));
- assert(dst);
+ if (!dst)
+ die("memory allocation failed - maybe length is too large?\n");
+
src = calloc(length, sizeof(char));
- assert(src);
+ if (!src)
+ die("memory allocation failed - maybe length is too large?\n");
if (bench_format == BENCH_FORMAT_DEFAULT) {
printf("# Copying %s Bytes from %p to %p ...\n\n",
@@ -136,8 +143,9 @@
if (use_clock) {
init_clock();
clock_start = get_clock();
- } else
+ } else {
BUG_ON(gettimeofday(&tv_start, NULL));
+ }
routines[i].fn(dst, src, length);
@@ -176,9 +184,8 @@
printf("%lf\n", bps);
break;
default:
- /* reaching here is something disaster */
- fprintf(stderr, "Unknown format:%d\n", bench_format);
- exit(1);
+ /* reaching this means there's some disaster: */
+ die("unknown format: %d\n", bench_format);
break;
}