f2fs: fix to write node pages with WRITE_SYNC
This patch fixes performance regression of dbench reported by
Alex <hbx7d@yandex.com>.
This issue was revealed by Phoronix tests results:
http://www.phoronix.com/scan.php?page=article&item=linux_314_ssdfs&num=2
It turns out that we need to assign WRITE_SYNC to the node writes, if
fsync is triggered.
The performance numbers are like below, which is measured by Alex.
1. 355MB/s ext4
2. 225MB/s f2fs : WRITE for node writes
3. 525MB/s f2fs : WRITE_SYNC for node writes
Reported-And-Tested-by: Alex <hbx7d@yandex.com>.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 00f937e..a4cc1d6 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -115,7 +115,7 @@
int ret = 0;
bool need_cp = false;
struct writeback_control wbc = {
- .sync_mode = WB_SYNC_NONE,
+ .sync_mode = WB_SYNC_ALL,
.nr_to_write = LONG_MAX,
.for_reclaim = 0,
};