f2fs_io: measure performance of write()

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/tools/f2fs_io/f2fs_io.c b/tools/f2fs_io/f2fs_io.c
index 70a077a..6177d29 100644 (file)
--- a/tools/f2fs_io/f2fs_io.c
+++ b/tools/f2fs_io/f2fs_io.c
@@ -130,6 +130,25 @@ static void full_write(int fd, const void *buf, size_t count)
        }
 }
 
+#if defined(__APPLE__)
+static u64 get_current_us()
+{
+#ifdef HAVE_MACH_TIME_H
+       return mach_absolute_time() / 1000;
+#else
+       return 0;
+#endif
+}
+#else
+static u64 get_current_us()
+{
+       struct timespec t;
+       t.tv_sec = t.tv_nsec = 0;
+       clock_gettime(CLOCK_BOOTTIME, &t);
+       return (u64)t.tv_sec * 1000000LL + t.tv_nsec / 1000;
+}
+#endif
+
 #define fsync_desc "fsync"
 #define fsync_help                                             \
 "f2fs_io fsync [file]\n\n"                                     \
@@ -434,6 +453,7 @@ static void do_write(int argc, char **argv, const struct cmd_desc *cmd)
        unsigned bs, count, i;
        int flags = 0;
        int fd;
+       u64 total_time = 0, max_time = 0, max_time_t = 0;
 
        srand(time(0));
 
@@ -468,6 +488,7 @@ static void do_write(int argc, char **argv, const struct cmd_desc *cmd)
 
        fd = xopen(argv[6], O_CREAT | O_WRONLY | flags, 0755);
 
+       total_time = get_current_us();
        for (i = 0; i < count; i++) {
                if (!strcmp(argv[4], "inc_num"))
                        *(int *)buf = inc_num++;
@@ -475,13 +496,20 @@ static void do_write(int argc, char **argv, const struct cmd_desc *cmd)
                        *(int *)buf = rand();
 
                /* write data */
+               max_time_t = get_current_us();
                ret = pwrite(fd, buf, buf_size, offset + buf_size * i);
+               max_time_t = get_current_us() - max_time_t;
+               if (max_time < max_time_t)
+                       max_time = max_time_t;
                if (ret != buf_size)
                        break;
                written += ret;
        }
 
-       printf("Written %"PRIu64" bytes with pattern=%s\n", written, argv[4]);
+       printf("Written %"PRIu64" bytes with pattern=%s, total_time=%"PRIu64" us, max_latency=%"PRIu64" us\n",
+                               written, argv[4],
+                               get_current_us() - total_time,
+                               max_time);
        exit(0);
 }