The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable@xxxxxxxxxxxxxxx>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 02444f2ac26eae6385a65fcd66915084d15dffba # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable@xxxxxxxxxxxxxxx>' --in-reply-to '2024012707-pushover-sherry-f45f@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: 02444f2ac26e ("btrfs: zoned: optimize hint byte for zoned allocator") b271fee9a41c ("btrfs: zoned: factor out prepare_allocation_zoned()") c2707a255623 ("btrfs: zoned: add a dedicated data relocation block group") be1a1d7a5d24 ("btrfs: zoned: finish fully written block group") a85f05e59bc1 ("btrfs: zoned: avoid chunk allocation if active block group has enough space") a12b0dc0aa4d ("btrfs: move ffe_ctl one level up") 2e654e4bb9ac ("btrfs: zoned: activate block group on allocation") afba2bc036b0 ("btrfs: zoned: implement active zone tracking") dafc340dbd10 ("btrfs: zoned: introduce physical_map to btrfs_block_group") 98173255bddd ("btrfs: zoned: calculate free space from zone capacity") 8eae532be753 ("btrfs: zoned: load zone capacity information from devices") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 02444f2ac26eae6385a65fcd66915084d15dffba Mon Sep 17 00:00:00 2001 From: Naohiro Aota <naohiro.aota@xxxxxxx> Date: Tue, 19 Dec 2023 01:02:29 +0900 Subject: [PATCH] btrfs: zoned: optimize hint byte for zoned allocator Writing sequentially to a huge file on btrfs on a SMR HDD revealed a decline of the performance (220 MiB/s to 30 MiB/s after 500 minutes). The performance goes down because of increased latency of the extent allocation, which is induced by a traversing of a lot of full block groups. So, this patch optimizes the ffe_ctl->hint_byte by choosing a block group with sufficient size from the active block group list, which does not contain full block groups. After applying the patch, the performance is maintained well. Fixes: 2eda57089ea3 ("btrfs: zoned: implement sequential extent allocation") CC: stable@xxxxxxxxxxxxxxx # 5.15+ Reviewed-by: Johannes Thumshirn <johannes.thumshirn@xxxxxxx> Signed-off-by: Naohiro Aota <naohiro.aota@xxxxxxx> Signed-off-by: David Sterba <dsterba@xxxxxxxx> diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index d260b970bec7..6d680031211a 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -4311,6 +4311,24 @@ static int prepare_allocation_zoned(struct btrfs_fs_info *fs_info, if (fs_info->data_reloc_bg) ffe_ctl->hint_byte = fs_info->data_reloc_bg; spin_unlock(&fs_info->relocation_bg_lock); + } else if (ffe_ctl->flags & BTRFS_BLOCK_GROUP_DATA) { + struct btrfs_block_group *block_group; + + spin_lock(&fs_info->zone_active_bgs_lock); + list_for_each_entry(block_group, &fs_info->zone_active_bgs, active_bg_list) { + /* + * No lock is OK here because avail is monotinically + * decreasing, and this is just a hint. + */ + u64 avail = block_group->zone_capacity - block_group->alloc_offset; + + if (block_group_bits(block_group, ffe_ctl->flags) && + avail >= ffe_ctl->num_bytes) { + ffe_ctl->hint_byte = block_group->start; + break; + } + } + spin_unlock(&fs_info->zone_active_bgs_lock); } return 0;