From 243192b6764990e7fa0e22ea65b4d12f3294471c Mon Sep 17 00:00:00 2001 From: Boris Burkov Date: Thu, 25 Jan 2024 14:10:30 -0800 Subject: [PATCH] btrfs: report reclaim stats in sysfs When evaluating various reclaim strategies/thresholds against each other, it is useful to collect data about the amount of reclaim happening. Expose a count, error count, and byte count via sysfs per space_info. Note that this is only for automatic reclaim, not manually invoked balances or other codepaths that use "relocate_block_group" Reviewed-by: Josef Bacik Reviewed-by: Johannes Thumshirn Signed-off-by: Boris Burkov Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/block-group.c | 10 ++++++++++ fs/btrfs/space-info.h | 18 ++++++++++++++++++ fs/btrfs/sysfs.c | 6 ++++++ 3 files changed, 34 insertions(+) diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c index db666f9807ea..b530302b469d 100644 --- a/fs/btrfs/block-group.c +++ b/fs/btrfs/block-group.c @@ -1829,6 +1829,7 @@ void btrfs_reclaim_bgs_work(struct work_struct *work) list_sort(NULL, &fs_info->reclaim_bgs, reclaim_bgs_cmp); while (!list_empty(&fs_info->reclaim_bgs)) { u64 zone_unusable; + u64 reclaimed; int ret = 0; bg = list_first_entry(&fs_info->reclaim_bgs, @@ -1921,12 +1922,21 @@ void btrfs_reclaim_bgs_work(struct work_struct *work) div64_u64(bg->used * 100, bg->length), div64_u64(zone_unusable * 100, bg->length)); trace_btrfs_reclaim_block_group(bg); + reclaimed = bg->used; ret = btrfs_relocate_chunk(fs_info, bg->start); if (ret) { btrfs_dec_block_group_ro(bg); btrfs_err(fs_info, "error relocating chunk %llu", bg->start); + reclaimed = 0; + spin_lock(&space_info->lock); + space_info->reclaim_errors++; + spin_unlock(&space_info->lock); } + spin_lock(&space_info->lock); + space_info->reclaim_count++; + space_info->reclaim_bytes += reclaimed; + spin_unlock(&space_info->lock); next: if (ret) { diff --git a/fs/btrfs/space-info.h b/fs/btrfs/space-info.h index a733458fd13b..98ea35ae60fe 100644 --- a/fs/btrfs/space-info.h +++ b/fs/btrfs/space-info.h @@ -165,6 +165,24 @@ struct btrfs_space_info { struct kobject kobj; struct kobject *block_group_kobjs[BTRFS_NR_RAID_TYPES]; + + /* + * Monotonically increasing counter of block group reclaim attempts + * Exposed in /sys/fs//allocation//reclaim_count + */ + u64 reclaim_count; + + /* + * Monotonically increasing counter of reclaimed bytes + * Exposed in /sys/fs//allocation//reclaim_bytes + */ + u64 reclaim_bytes; + + /* + * Monotonically increasing counter of reclaim errors + * Exposed in /sys/fs//allocation//reclaim_errors + */ + u64 reclaim_errors; }; struct reserve_ticket { diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c index af545b6b1190..919c7ba45121 100644 --- a/fs/btrfs/sysfs.c +++ b/fs/btrfs/sysfs.c @@ -894,6 +894,9 @@ SPACE_INFO_ATTR(bytes_readonly); SPACE_INFO_ATTR(bytes_zone_unusable); SPACE_INFO_ATTR(disk_used); SPACE_INFO_ATTR(disk_total); +SPACE_INFO_ATTR(reclaim_count); +SPACE_INFO_ATTR(reclaim_bytes); +SPACE_INFO_ATTR(reclaim_errors); BTRFS_ATTR_RW(space_info, chunk_size, btrfs_chunk_size_show, btrfs_chunk_size_store); BTRFS_ATTR(space_info, size_classes, btrfs_size_classes_show); @@ -949,6 +952,9 @@ static struct attribute *space_info_attrs[] = { BTRFS_ATTR_PTR(space_info, bg_reclaim_threshold), BTRFS_ATTR_PTR(space_info, chunk_size), BTRFS_ATTR_PTR(space_info, size_classes), + BTRFS_ATTR_PTR(space_info, reclaim_count), + BTRFS_ATTR_PTR(space_info, reclaim_bytes), + BTRFS_ATTR_PTR(space_info, reclaim_errors), #ifdef CONFIG_BTRFS_DEBUG BTRFS_ATTR_PTR(space_info, force_chunk_alloc), #endif