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| author | Chris Mason <chris.mason@oracle.com> | 2008-09-24 18:51:30 (GMT) |
|---|---|---|
| committer | Chris Mason <chris.mason@oracle.com> | 2008-09-25 19:41:59 (GMT) |
| commit | 24ab9cd85c11bccacbd0cce7f8e1aebd4930404c (patch) | |
| tree | 2ace993dd54bb6dd94fdd4c0cb03813c6bf4c6a3 /fs | |
| parent | 4434c33c7f233a7ee5dcaf357fbf795818ea8861 (diff) | |
| download | linux-24ab9cd85c11bccacbd0cce7f8e1aebd4930404c.tar.xz | |
Btrfs: Raise thresholds for metadata writeback
Btrfs metadata writeback is fairly expensive. Once a tree block is written
it must be cowed before it can be changed again. The btree writepages
code has a threshold based on a count of dirty btree bytes which is
updated as IO is sent out.
This changes btree_writepages to skip the writeout if there are less
than 32MB of dirty bytes from the btrees, improving performance
across many workloads.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/btrfs/disk-io.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index dffb8da..71e81f3 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -556,7 +556,7 @@ static int btree_writepages(struct address_space *mapping, if (wbc->sync_mode == WB_SYNC_NONE) { u64 num_dirty; u64 start = 0; - unsigned long thresh = 8 * 1024 * 1024; + unsigned long thresh = 32 * 1024 * 1024; if (wbc->for_kupdate) return 0; @@ -690,7 +690,7 @@ struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root, int btrfs_write_tree_block(struct extent_buffer *buf) { return btrfs_fdatawrite_range(buf->first_page->mapping, buf->start, - buf->start + buf->len - 1, WB_SYNC_NONE); + buf->start + buf->len - 1, WB_SYNC_ALL); } int btrfs_wait_tree_block_writeback(struct extent_buffer *buf) |