From 6a3afb6ac6dfab158ebdd4b87941178f58c8939f Mon Sep 17 00:00:00 2001 From: Zhang Yi Date: Wed, 29 Nov 2023 19:47:40 +0800 Subject: jbd2: increase the journal IO's priority Current jbd2 only add REQ_SYNC for descriptor block, metadata log buffer, commit buffer and superblock buffer, the submitted IO could be throttled by writeback throttle in block layer, that could lead to priority inversion in some cases. The log IO looks like a kind of high priority metadata IO, so it should not be throttled by WBT like QOS policies in block layer, let's add REQ_SYNC | REQ_IDLE to exempt from writeback throttle, and also add REQ_META together indicates it's a metadata IO. Signed-off-by: Zhang Yi Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20231129114740.2686201-2-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o --- fs/jbd2/commit.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) (limited to 'fs/jbd2/commit.c') diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c index 8d6f934c3d95..9bdb377a348f 100644 --- a/fs/jbd2/commit.c +++ b/fs/jbd2/commit.c @@ -119,7 +119,7 @@ static int journal_submit_commit_record(journal_t *journal, struct commit_header *tmp; struct buffer_head *bh; struct timespec64 now; - blk_opf_t write_flags = REQ_OP_WRITE | REQ_SYNC; + blk_opf_t write_flags = REQ_OP_WRITE | JBD2_JOURNAL_REQ_FLAGS; *cbh = NULL; @@ -395,8 +395,7 @@ void jbd2_journal_commit_transaction(journal_t *journal) */ jbd2_journal_update_sb_log_tail(journal, journal->j_tail_sequence, - journal->j_tail, - REQ_SYNC); + journal->j_tail, 0); mutex_unlock(&journal->j_checkpoint_mutex); } else { jbd2_debug(3, "superblock not updated\n"); @@ -715,6 +714,7 @@ start_journal_io: for (i = 0; i < bufs; i++) { struct buffer_head *bh = wbuf[i]; + /* * Compute checksum. */ @@ -727,7 +727,8 @@ start_journal_io: clear_buffer_dirty(bh); set_buffer_uptodate(bh); bh->b_end_io = journal_end_buffer_io_sync; - submit_bh(REQ_OP_WRITE | REQ_SYNC, bh); + submit_bh(REQ_OP_WRITE | JBD2_JOURNAL_REQ_FLAGS, + bh); } cond_resched(); -- cgit