The patch below does not apply to the 6.6-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@vger.kernel.org.
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-6.6.y git checkout FETCH_HEAD git cherry-pick -x 02444f2ac26eae6385a65fcd66915084d15dffba # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2024012704-outclass-seventy-a7bb@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
Possible dependencies:
02444f2ac26e ("btrfs: zoned: optimize hint byte for zoned allocator") b271fee9a41c ("btrfs: zoned: factor out prepare_allocation_zoned()")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 02444f2ac26eae6385a65fcd66915084d15dffba Mon Sep 17 00:00:00 2001 From: Naohiro Aota naohiro.aota@wdc.com 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@vger.kernel.org # 5.15+ 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
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;