diff options
| author | Chao Yu | 2015-07-06 20:31:49 +0800 |
|---|---|---|
| committer | Jaegeuk Kim | 2015-08-04 14:09:57 -0700 |
| commit | bb96a8d51e523c162b436c4545eb1a4e9f9f530e (patch) | |
| tree | 680dae8bf11783079ce249d387bff7a1228161db | |
| parent | 741a7bea79eae6361c8d7499f1f6a900b65c120e (diff) | |
f2fs: enhance multithread performance
In ->writepages, we use writepages mutex lock to serialize all block
address allocation and page submitting pairs from different inodes.
This method makes our delayed dirty pages of one inode being written
continously as many as possible.
But there is one problem that we did not submit current cached bio in
protection region of writepages mutex lock, so there is a small chance
that we submit the one of other thread's as below, resulting in
splitting more bios.
thread 1 thread 2
->writepages
lock(writepages)
->write_cache_pages
unlock(writepages)
lock(writepages)
->write_cache_pages
->f2fs_submit_merged_bio
->writepage
unlock(writepages)
fs_mark-6535 [002] .... 2242.270230: f2fs_submit_write_bio: dev = (1,0), WRITE_SYNC, DATA, sector = 5766152, size = 524288
fs_mark-6536 [000] .... 2242.270361: f2fs_submit_write_bio: dev = (1,0), WRITE_SYNC, DATA, sector = 5767176, size = 4096
fs_mark-6536 [000] .... 2242.270370: f2fs_submit_write_bio: dev = (1,0), WRITE_SYNC, NODE, sector = 8138112, size = 4096
fs_mark-6535 [002] .... 2242.270776: f2fs_submit_write_bio: dev = (1,0), WRITE_SYNC, DATA, sector = 5767184, size = 516096
This may really increase time of block layer works, and may cause
larger IO lantency.
This patch moves the submitting operation into region of writepages
mutex lock to avoid bio splits when concurrently writebacking is
intensive.
my test environment: virtual machine,
intel cpu i5 2500, 8GB size memory, 4GB size ramdisk
time fs_mark -t 16 -L 1 -s 524288 -S 1 -d /mnt/f2fs/
before:
real 0m4.244s
user 0m0.088s
sys 0m12.336s
after:
real 0m3.822s
user 0m0.072s
sys 0m10.760s
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
| -rw-r--r-- | fs/f2fs/data.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index cdc1c2b781b8..3e4402f661d7 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -1672,11 +1672,10 @@ static int f2fs_write_data_pages(struct address_space *mapping, locked = true; } ret = write_cache_pages(mapping, wbc, __f2fs_writepage, mapping); + f2fs_submit_merged_bio(sbi, DATA, WRITE); if (locked) mutex_unlock(&sbi->writepages); - f2fs_submit_merged_bio(sbi, DATA, WRITE); - remove_dirty_dir_inode(inode); wbc->nr_to_write = max((long)0, wbc->nr_to_write - diff); |