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btrfs: report reclaim stats in sysfs

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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 <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Boris Burkov 2024-01-25 14:10:30 -08:00 committed by David Sterba
parent a5b3abb18c
commit 243192b676
3 changed files with 34 additions and 0 deletions
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10
fs/btrfs/block-group.c
View File

@ -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) {

18
fs/btrfs/space-info.h
View File

@ -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/<uuid>/allocation/<type>/reclaim_count
*/
u64 reclaim_count;
/*
* Monotonically increasing counter of reclaimed bytes
* Exposed in /sys/fs/<uuid>/allocation/<type>/reclaim_bytes
*/
u64 reclaim_bytes;
/*
* Monotonically increasing counter of reclaim errors
* Exposed in /sys/fs/<uuid>/allocation/<type>/reclaim_errors
*/
u64 reclaim_errors;
};
struct reserve_ticket {

6
fs/btrfs/sysfs.c
View File

@ -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