Messages in this thread Patch in this message | | | From | Jaegeuk Kim <> | Subject | [PATCH] f2fs: fix performance issue observed with multi-thread sequential read | Date | Thu, 9 Aug 2018 19:37:58 -0700 |
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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> --- fs/f2fs/data.c | 14 ++++++++++++-- fs/f2fs/f2fs.h | 1 + fs/f2fs/super.c | 1 + 3 files changed, 14 insertions(+), 2 deletions(-)
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 45f043ee48bd..e042d050b87d 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -2132,6 +2132,7 @@ static int __f2fs_write_data_pages(struct address_space *mapping, struct f2fs_sb_info *sbi = F2FS_I_SB(inode); struct blk_plug plug; int ret; + bool locked = false; /* deal with chardevs and other special file */ if (!mapping->a_ops->writepage) @@ -2157,15 +2158,24 @@ 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) + if (wbc->sync_mode == WB_SYNC_ALL) { atomic_inc(&sbi->wb_sync_req[DATA]); - else if (atomic_read(&sbi->wb_sync_req[DATA])) + mutex_lock(&sbi->writepages); + locked = true; + } else if (atomic_read(&sbi->wb_sync_req[DATA])) { goto skip_write; + } else { + atomic_inc(&sbi->wb_sync_req[DATA]); + mutex_lock(&sbi->writepages); + } blk_start_plug(&plug); ret = f2fs_write_cache_pages(mapping, wbc, io_type); blk_finish_plug(&plug); + if (locked) + mutex_unlock(&sbi->writepages); + if (wbc->sync_mode == WB_SYNC_ALL) atomic_dec(&sbi->wb_sync_req[DATA]); /* diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index b1c127d8383b..29bbc55cbc0b 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -1133,6 +1133,7 @@ struct f2fs_sb_info { struct rw_semaphore sb_lock; /* lock for raw super block */ int valid_super_block; /* valid super block no */ unsigned long s_flag; /* flags for sbi */ + struct mutex writepages; /* mutex for writepages() */ #ifdef CONFIG_BLK_DEV_ZONED unsigned int blocks_per_blkz; /* F2FS blocks per zone */ diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index be41dbd7b261..53d70b64fea1 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -2842,6 +2842,7 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent) /* 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); -- 2.17.0.441.gb46fe60e1d-goog
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