From: Jens Axboe <axboe@suse.de>
Date: Tue, 25 Oct 2005 09:23:09 +0000 (+0200)
Subject: [PATCH] fio: avoid lseek() if cur_off == offset
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=63a09e51a1546e8649411243cae2763451f69b86;p=disktools.git

[PATCH] fio: avoid lseek() if cur_off == offset
---

diff --git a/fio.c b/fio.c
index 6c54917..c7b92c5 100644
--- a/fio.c
+++ b/fio.c
@@ -197,6 +197,8 @@ struct thread_data {
 	unsigned long long file_offset;
 	cpu_set_t cpumask;
 
+	off_t cur_off;
+
 	io_context_t aio_ctx;
 	unsigned int aio_depth;
 	struct io_event *aio_events;
@@ -477,6 +479,8 @@ static void do_sync_io(struct thread_data *td)
 	unsigned long blocks, msec, usec;
 	struct timeval e;
 
+	td->cur_off = 0;
+
 	for (blocks = 0; blocks < td->blocks; blocks++) {
 		struct io_u *io_u;
 		int ret;
@@ -486,9 +490,11 @@ static void do_sync_io(struct thread_data *td)
 
 		io_u = get_io_u(td);
 
-		if (lseek(td->fd, io_u->offset, SEEK_SET) == -1) {
-			td->error = errno;
-			break;
+		if (td->cur_off != io_u->offset) {
+			if (lseek(td->fd, io_u->offset, SEEK_SET) == -1) {
+				td->error = errno;
+				break;
+			}
 		}
 
 		if (td->delay_sleep)
@@ -506,6 +512,7 @@ static void do_sync_io(struct thread_data *td)
 		}
 
 		td->io_blocks++;
+		td->cur_off = io_u->offset + io_u->buflen;
 
 		if (should_fsync(td) && td->fsync_blocks &&
 		    (td->io_blocks % td->fsync_blocks) == 0)