diff options
| author | Julian Sun <sunjunchao@bytedance.com> | 2025-08-27 20:18:12 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-12-07 06:12:26 +0900 |
| commit | 81236ea82fce3f99c092b08aec2e5b5ecd05f0ff (patch) | |
| tree | 2ee838de21391d2a5979c9f54fc7661f71d9bb42 /fs/ext4 | |
| parent | add8458cac0b33a5e7a6b98457b38baea9600859 (diff) | |
ext4: increase IO priority of fastcommit
[ Upstream commit 46e75c56dfeafb6756773b71cabe187a6886859a ]
The following code paths may result in high latency or even task hangs:
1. fastcommit io is throttled by wbt.
2. jbd2_fc_wait_bufs() might wait for a long time while
JBD2_FAST_COMMIT_ONGOING is set in journal->flags, and then
jbd2_journal_commit_transaction() waits for the
JBD2_FAST_COMMIT_ONGOING bit for a long time while holding the write
lock of j_state_lock.
3. start_this_handle() waits for read lock of j_state_lock which
results in high latency or task hang.
Given the fact that ext4_fc_commit() already modifies the current
process' IO priority to match that of the jbd2 thread, it should be
reasonable to match jbd2's IO submission flags as well.
Suggested-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Julian Sun <sunjunchao@bytedance.com>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Message-ID: <20250827121812.1477634-1-sunjunchao@bytedance.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'fs/ext4')
| -rw-r--r-- | fs/ext4/fast_commit.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/ext4/fast_commit.c b/fs/ext4/fast_commit.c index e2062cd4adad..94f90032ca56 100644 --- a/fs/ext4/fast_commit.c +++ b/fs/ext4/fast_commit.c @@ -675,7 +675,7 @@ void ext4_fc_track_range(handle_t *handle, struct inode *inode, ext4_lblk_t star static void ext4_fc_submit_bh(struct super_block *sb, bool is_tail) { - blk_opf_t write_flags = REQ_SYNC; + blk_opf_t write_flags = JBD2_JOURNAL_REQ_FLAGS; struct buffer_head *bh = EXT4_SB(sb)->s_fc_bh; /* Add REQ_FUA | REQ_PREFLUSH only its tail */ |