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| author | Christoph Hellwig <hch@lst.de> | 2010-06-17 08:54:16 +0200 |
|---|---|---|
| committer | Jens Axboe <jaxboe@fusionio.com> | 2010-08-07 18:15:44 +0200 |
| commit | 41f2df62894bfcd3bf868af916b32b90aa7168dc (patch) | |
| tree | b582399975cd1cf19aa8b6e67623f252b7cada85 | |
| parent | 01b6b67edabe864391163dc6405e2cb454f108db (diff) | |
| download | kernel_samsung_smdk4412-41f2df62894bfcd3bf868af916b32b90aa7168dc.zip kernel_samsung_smdk4412-41f2df62894bfcd3bf868af916b32b90aa7168dc.tar.gz kernel_samsung_smdk4412-41f2df62894bfcd3bf868af916b32b90aa7168dc.tar.bz2 | |
block: BARRIER request should imply SYNC
A barrier request should by defintion have priority in get_request
and let the queue be unplugged immediately as it's blocking all forward
progress due to the queue draining.
Most filesystems already get this implicitly by the way how submit_bh
treats the buffer_ordered flag, and gfs2 sets it explicitly. But btrfs
and XFS are still forgetting to set the flag, as is blkdev_issue_flush
and some places in DM/MD.
For XFS on metadata heavy workloads this gives a consistent speedup
in the 2-3% range.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
| -rw-r--r-- | fs/gfs2/log.c | 2 | ||||
| -rw-r--r-- | include/linux/fs.h | 4 |
2 files changed, 3 insertions, 3 deletions
diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c index 6a857e2..efc3539 100644 --- a/fs/gfs2/log.c +++ b/fs/gfs2/log.c @@ -595,7 +595,7 @@ static void log_write_header(struct gfs2_sbd *sdp, u32 flags, int pull) if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags)) goto skip_barrier; get_bh(bh); - submit_bh(WRITE_SYNC | (1 << BIO_RW_BARRIER) | (1 << BIO_RW_META), bh); + submit_bh(WRITE_BARRIER | (1 << BIO_RW_META), bh); wait_on_buffer(bh); if (buffer_eopnotsupp(bh)) { clear_buffer_eopnotsupp(bh); diff --git a/include/linux/fs.h b/include/linux/fs.h index 68ca1b0..5988788 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -136,7 +136,7 @@ struct inodes_stat_t { * SWRITE_SYNC * SWRITE_SYNC_PLUG Like WRITE_SYNC/WRITE_SYNC_PLUG, but locks the buffer. * See SWRITE. - * WRITE_BARRIER Like WRITE, but tells the block layer that all + * WRITE_BARRIER Like WRITE_SYNC, but tells the block layer that all * previously submitted writes must be safely on storage * before this one is started. Also guarantees that when * this write is complete, it itself is also safely on @@ -159,7 +159,7 @@ struct inodes_stat_t { #define SWRITE_SYNC_PLUG \ (SWRITE | (1 << BIO_RW_SYNCIO) | (1 << BIO_RW_NOIDLE)) #define SWRITE_SYNC (SWRITE_SYNC_PLUG | (1 << BIO_RW_UNPLUG)) -#define WRITE_BARRIER (WRITE | (1 << BIO_RW_BARRIER)) +#define WRITE_BARRIER (WRITE_SYNC | (1 << BIO_RW_BARRIER)) /* * These aren't really reads or writes, they pass down information about |