From: Naohiro Aota naohiro.aota@wdc.com
[ Upstream commit 85e79ec7b78f863178ca488fd8cb5b3de6347756 ]
The commit 79417d040f4f ("btrfs: zoned: disable metadata overcommit for zoned") disabled the metadata over-commit to track active zones properly.
However, it also introduced a heavy overhead by allocating new metadata block groups and/or flushing dirty buffers to release the space reservations. Specifically, a workload (write only without any sync operations) worsen its performance from 343.77 MB/sec (v5.19) to 182.89 MB/sec (v6.0).
The performance is still bad on current misc-next which is 187.95 MB/sec. And, with this patch applied, it improves back to 326.70 MB/sec (+73.82%).
This patch introduces a new fs_info->flag BTRFS_FS_NO_OVERCOMMIT to indicate it needs to disable the metadata over-commit. The flag is enabled when a device with max active zones limit is loaded into a file-system.
Fixes: 79417d040f4f ("btrfs: zoned: disable metadata overcommit for zoned") CC: stable@vger.kernel.org # 6.0+ Reviewed-by: Johannes Thumshirn johannes.thumshirn@wdc.com Signed-off-by: Naohiro Aota naohiro.aota@wdc.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/btrfs/ctree.h | 6 ++++++ fs/btrfs/space-info.c | 3 ++- fs/btrfs/zoned.c | 2 ++ 3 files changed, 10 insertions(+), 1 deletion(-)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 9e6d48ff4597..a3febabacec0 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -590,6 +590,12 @@ enum { /* Indicate we have to finish a zone to do next allocation. */ BTRFS_FS_NEED_ZONE_FINISH,
+ /* + * Indicate metadata over-commit is disabled. This is set when active + * zone tracking is needed. + */ + BTRFS_FS_NO_OVERCOMMIT, + #if BITS_PER_LONG == 32 /* Indicate if we have error/warn message printed on 32bit systems */ BTRFS_FS_32BIT_ERROR, diff --git a/fs/btrfs/space-info.c b/fs/btrfs/space-info.c index f171bf875633..65c010159fb5 100644 --- a/fs/btrfs/space-info.c +++ b/fs/btrfs/space-info.c @@ -404,7 +404,8 @@ int btrfs_can_overcommit(struct btrfs_fs_info *fs_info, return 0;
used = btrfs_space_info_used(space_info, true); - if (btrfs_is_zoned(fs_info) && (space_info->flags & BTRFS_BLOCK_GROUP_METADATA)) + if (test_bit(BTRFS_FS_NO_OVERCOMMIT, &fs_info->flags) && + (space_info->flags & BTRFS_BLOCK_GROUP_METADATA)) avail = 0; else avail = calc_available_free_space(fs_info, space_info, flush); diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c index c9e2b0c85309..056f002263db 100644 --- a/fs/btrfs/zoned.c +++ b/fs/btrfs/zoned.c @@ -538,6 +538,8 @@ int btrfs_get_dev_zone_info(struct btrfs_device *device, bool populate_cache) } atomic_set(&zone_info->active_zones_left, max_active_zones - nactive); + /* Overcommit does not work well with active zone tacking. */ + set_bit(BTRFS_FS_NO_OVERCOMMIT, &fs_info->flags); }
/* Validate superblock log */