f2fs: fix performance issue observed with multi-thread sequential read
This reverts the commit - "b93f771 - f2fs: remove writepages lock"
to fix the drop in sequential read throughput.
Test: ./tiotest -t 32 -d /data/tio_tmp -f 32 -b 524288 -k 1 -k 3 -L
device: UFS
Before -
read throughput: 185 MB/s
total read requests: 85177 (of these ~80000 are 4KB size requests).
total write requests: 2546 (of these ~2208 requests are written in 512KB).
After -
read throughput: 758 MB/s
total read requests: 2417 (of these ~2042 are 512KB reads).
total write requests: 2701 (of these ~2034 requests are written in 512KB).
Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 4f7c1b5..bba0cd4 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -2846,6 +2846,7 @@
/* init f2fs-specific super block info */
sbi->valid_super_block = valid_super_block;
mutex_init(&sbi->gc_mutex);
+ mutex_init(&sbi->writepages);
mutex_init(&sbi->cp_mutex);
init_rwsem(&sbi->node_write);
init_rwsem(&sbi->node_change);