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| author | Jaegeuk Kim <jaegeuk@kernel.org> | 2017-03-28 18:07:38 -0700 |
|---|---|---|
| committer | Jaegeuk Kim <jaegeuk@kernel.org> | 2017-04-05 11:05:06 -0700 |
| commit | 687de7f1010cb819d04b768556960d3689abe02b (patch) | |
| tree | c32a4ccac2d084d51e2074e7184598bf4cd37349 /fs/f2fs | |
| parent | ef095d19e82f25bbdead472b8b71f4ef3b7a636d (diff) | |
| download | linux-stable-687de7f1010cb819d04b768556960d3689abe02b.tar.gz linux-stable-687de7f1010cb819d04b768556960d3689abe02b.tar.bz2 linux-stable-687de7f1010cb819d04b768556960d3689abe02b.zip | |
f2fs: avoid IO split due to mixed WB_SYNC_ALL and WB_SYNC_NONE
If two threads try to flush dirty pages in different inodes respectively,
f2fs_write_data_pages() will produce WRITE and WRITE_SYNC one at a time,
resulting in a lot of 4KB seperated IOs.
So, this patch gives higher priority to WB_SYNC_ALL IOs and gathers write
IOs with a big WRITE_SYNC'ed bio.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Diffstat (limited to 'fs/f2fs')
| -rw-r--r-- | fs/f2fs/data.c | 15 | ||||
| -rw-r--r-- | fs/f2fs/f2fs.h | 3 | ||||
| -rw-r--r-- | fs/f2fs/super.c | 2 |
3 files changed, 18 insertions, 2 deletions
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 8f36080b47c4..b1cac6d85bcb 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -1605,8 +1605,10 @@ continue_unlock: last_idx = page->index; } - if (--wbc->nr_to_write <= 0 && - wbc->sync_mode == WB_SYNC_NONE) { + /* give a priority to WB_SYNC threads */ + if ((atomic_read(&F2FS_M_SB(mapping)->wb_sync_req) || + --wbc->nr_to_write <= 0) && + wbc->sync_mode == WB_SYNC_NONE) { done = 1; break; } @@ -1662,9 +1664,18 @@ static int f2fs_write_data_pages(struct address_space *mapping, trace_f2fs_writepages(mapping->host, wbc, DATA); + /* to avoid spliting IOs due to mixed WB_SYNC_ALL and WB_SYNC_NONE */ + if (wbc->sync_mode == WB_SYNC_ALL) + atomic_inc(&sbi->wb_sync_req); + else if (atomic_read(&sbi->wb_sync_req)) + goto skip_write; + blk_start_plug(&plug); ret = f2fs_write_cache_pages(mapping, wbc); blk_finish_plug(&plug); + + if (wbc->sync_mode == WB_SYNC_ALL) + atomic_dec(&sbi->wb_sync_req); /* * if some pages were truncated, we cannot guarantee its mapping->host * to detect pending bios. diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index fc90e5317159..cca46e0ff2e4 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -887,6 +887,9 @@ struct f2fs_sb_info { /* # of allocated blocks */ struct percpu_counter alloc_valid_block_count; + /* writeback control */ + atomic_t wb_sync_req; /* count # of WB_SYNC threads */ + /* valid inode count */ struct percpu_counter total_valid_inode_count; diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index 2e2e1b438ce1..21d5eaa2793e 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -1566,6 +1566,8 @@ static void init_sb_info(struct f2fs_sb_info *sbi) for (i = 0; i < NR_COUNT_TYPE; i++) atomic_set(&sbi->nr_pages[i], 0); + atomic_set(&sbi->wb_sync_req, 0); + INIT_LIST_HEAD(&sbi->s_list); mutex_init(&sbi->umount_mutex); mutex_init(&sbi->wio_mutex[NODE]); |