[PATCH 4/4] f2fs: remove two steps to flush dirty data pages

From: Jaegeuk Kim
Date: Thu May 26 2016 - 20:25:48 EST


If there is no cold page, we don't need to do a loop to flush dirty
data pages.

On /dev/pmem0,

1. dd if=/dev/zero of=/mnt/test/testfile bs=1M count=2048 conv=fsync
Before : 1.1 GB/s
After : 1.2 GB/s

2. dd if=/dev/zero of=/mnt/test/testfile bs=1M count=2048
Before : 2.2 GB/s
After : 2.3 GB/s

Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
---
fs/f2fs/data.c | 11 +----------
1 file changed, 1 insertion(+), 10 deletions(-)

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 85ceb2b..5dcd8db 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -1326,10 +1326,9 @@ static int f2fs_write_cache_pages(struct address_space *mapping,
int cycled;
int range_whole = 0;
int tag;
- int step = 0;

pagevec_init(&pvec, 0);
-next:
+
if (wbc->range_cyclic) {
writeback_index = mapping->writeback_index; /* prev offset */
index = writeback_index;
@@ -1384,9 +1383,6 @@ continue_unlock:
goto continue_unlock;
}

- if (step == is_cold_data(page))
- goto continue_unlock;
-
if (PageWriteback(page)) {
if (wbc->sync_mode != WB_SYNC_NONE)
f2fs_wait_on_page_writeback(page,
@@ -1421,11 +1417,6 @@ continue_unlock:
cond_resched();
}

- if (step < 1) {
- step++;
- goto next;
- }
-
if (!cycled && !done) {
cycled = 1;
index = 0;
--
2.6.3