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| author |   Chris Mason <clm@fb.com> | 2019-07-10 12:28:14 -0700 |
|---|---|---|
| committer |   David Sterba <dsterba@suse.com> | 2019-11-18 12:46:52 +0100 |
| commit | 08635bae0b4ceb08fe4c156a11c83baec397d36d (patch) | |
| tree | f4f5e77f3f7b40e25720ca7f13e8f285404186bb /fs/btrfs/volumes.h | |
| parent | btrfs: add __pure attribute to functions (diff) | |
| download | linux-dev-08635bae0b4ceb08fe4c156a11c83baec397d36d.tar.xz linux-dev-08635bae0b4ceb08fe4c156a11c83baec397d36d.zip | |
Btrfs: stop using btrfs_schedule_bio()
btrfs_schedule_bio() hands IO off to a helper thread to do the actual
submit_bio() call. This has been used to make sure async crc and
compression helpers don't get stuck on IO submission. To maintain good
performance, over time the IO submission threads duplicated some IO
scheduler characteristics such as high and low priority IOs and they
also made some ugly assumptions about request allocation batch sizes.
All of this cost at least one extra context switch during IO submission,
and doesn't fit well with the modern blkmq IO stack. So, this commit stops
using btrfs_schedule_bio(). We may need to adjust the number of async
helper threads for crcs and compression, but long term it's a better
path.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs/volumes.h')
| -rw-r--r-- | fs/btrfs/volumes.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h index 0ae0677a8d86..bc2bbaa485b7 100644 --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -436,7 +436,7 @@ int btrfs_read_chunk_tree(struct btrfs_fs_info *fs_info); int btrfs_alloc_chunk(struct btrfs_trans_handle *trans, u64 type); void btrfs_mapping_tree_free(struct extent_map_tree *tree); blk_status_t btrfs_map_bio(struct btrfs_fs_info *fs_info, struct bio *bio, - int mirror_num, int async_submit); + int mirror_num); int btrfs_open_devices(struct btrfs_fs_devices *fs_devices, fmode_t flags, void *holder); struct btrfs_device *btrfs_scan_one_device(const char *path, |