diff mbox series

[1/6] btrfs: report reclaim count in sysfs

Message ID c2ed218fbe9b4cd0c668389a178f3f80db43f95e.1706914865.git.boris@bur.io (mailing list archive)
State New, archived
Headers show
Series btrfs: dynamic and periodic block_group reclaim | expand

Commit Message

Boris Burkov Feb. 2, 2024, 11:12 p.m. UTC 
When evaluating various reclaim strategies/thresholds against each
other, it is useful to collect data about the amount of reclaim
happening. Expose it via sysfs per space_info.

Signed-off-by: Boris Burkov <boris@bur.io>
---
 fs/btrfs/block-group.c | 3 +++
 fs/btrfs/space-info.h  | 6 ++++++
 fs/btrfs/sysfs.c       | 2 ++
 3 files changed, 11 insertions(+)
diff mbox series

Patch

diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
index a9be9ac99222..7f05fdcee199 100644
--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -1858,6 +1858,9 @@  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);
+		spin_lock(&space_info->lock);
+		space_info->reclaim_count++;
+		spin_unlock(&space_info->lock);
 		ret = btrfs_relocate_chunk(fs_info, bg->start);
 		if (ret) {
 			btrfs_dec_block_group_ro(bg);
diff --git a/fs/btrfs/space-info.h b/fs/btrfs/space-info.h
index 92c595fed1b0..da3e68612d5c 100644
--- a/fs/btrfs/space-info.h
+++ b/fs/btrfs/space-info.h
@@ -156,6 +156,12 @@  struct btrfs_space_info {
 
 	struct kobject kobj;
 	struct kobject *block_group_kobjs[BTRFS_NR_RAID_TYPES];
+
+	/*
+	 * Monotonically increasing counter of relocated block groups.
+	 * Exposed in /sys/fs/<uuid>/allocation/<type>/reclaim_count
+	 */
+	u64 reclaim_count;
 };
 
 struct reserve_ticket {
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index 84c05246ffd8..1b866b2a01ce 100644
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -894,6 +894,7 @@  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);
 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 +950,7 @@  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),
 #ifdef CONFIG_BTRFS_DEBUG
 	BTRFS_ATTR_PTR(space_info, force_chunk_alloc),
 #endif