diff options
| author | Jan Kara <jack@suse.cz> | 2017-04-29 21:07:30 -0400 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2017-04-29 21:07:30 -0400 |
| commit | 5052b069acf73866d00077d8bc49983c3ee903e5 (patch) | |
| tree | 5822040784b621dbb32ae4b0a3e2f86586bdb1c3 /fs/jbd2 | |
| parent | c52c47e4b4fbe4284602fc2ccbfc4a4d8dc05b49 (diff) | |
| download | linux-5052b069acf73866d00077d8bc49983c3ee903e5.tar.gz | |
jbd2: fix dbench4 performance regression for 'nobarrier' mounts
Commit b685d3d65ac7 "block: treat REQ_FUA and REQ_PREFLUSH as synchronous" removed REQ_SYNC flag from WRITE_FUA implementation. Since JBD2 strips REQ_FUA and REQ_FLUSH flags from submitted IO when the filesystem is mounted with nobarrier mount option, journal superblock writes ended up being async writes after this patch and that caused heavy performance regression for dbench4 benchmark with high number of processes. In my test setup with HP RAID array with non-volatile write cache and 32 GB ram, dbench4 runs with 8 processes regressed by ~25%. Fix the problem by making sure journal superblock writes are always treated as synchronous since they generally block progress of the journalling machinery and thus the whole filesystem. Fixes: b685d3d65ac791406e0dfd8779cc9b3707fea5a3 CC: stable@vger.kernel.org Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/jbd2')
| -rw-r--r-- | fs/jbd2/journal.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index 9410ec462ba6..f1906fa54321 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -1361,7 +1361,7 @@ static int jbd2_write_superblock(journal_t *journal, int write_flags) jbd2_superblock_csum_set(journal, sb); get_bh(bh); bh->b_end_io = end_buffer_write_sync; - ret = submit_bh(REQ_OP_WRITE, write_flags, bh); + ret = submit_bh(REQ_OP_WRITE, write_flags | REQ_SYNC, bh); wait_on_buffer(bh); if (buffer_write_io_error(bh)) { clear_buffer_write_io_error(bh); |