[12/22] btrfs: keep track of discardable_bytes
diff mbox series

Message ID 1e8b884400b45f9a2f32ac4143b41abb27fd6fd4.1574282259.git.dennis@kernel.org
State New
Headers show
Series
  • btrfs: async discard support
Related show

Commit Message

Dennis Zhou Nov. 20, 2019, 9:51 p.m. UTC
Keep track of this metric so that we can understand how ahead or behind
we are in discarding rate.

Signed-off-by: Dennis Zhou <dennis@kernel.org>
---
 fs/btrfs/ctree.h            |  1 +
 fs/btrfs/discard.c          | 10 +++++++++
 fs/btrfs/free-space-cache.c | 41 +++++++++++++++++++++++++++++--------
 fs/btrfs/free-space-cache.h |  1 +
 fs/btrfs/sysfs.c            | 12 +++++++++++
 5 files changed, 56 insertions(+), 9 deletions(-)

Patch
diff mbox series

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index c37533a8a313..5b13bda52ab7 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -468,6 +468,7 @@  struct btrfs_discard_ctl {
 	struct btrfs_block_group *block_group;
 	struct list_head discard_list[BTRFS_NR_DISCARD_LISTS];
 	atomic_t discardable_extents;
+	atomic64_t discardable_bytes;
 };
 
 /* delayed seq elem */
diff --git a/fs/btrfs/discard.c b/fs/btrfs/discard.c
index a05180af74e2..074341c8242a 100644
--- a/fs/btrfs/discard.c
+++ b/fs/btrfs/discard.c
@@ -355,6 +355,7 @@  void btrfs_discard_update_discardable(struct btrfs_block_group *block_group,
 {
 	struct btrfs_discard_ctl *discard_ctl;
 	s32 extents_delta;
+	s64 bytes_delta;
 
 	if (!block_group ||
 	    !btrfs_test_opt(block_group->fs_info, DISCARD_ASYNC))
@@ -369,6 +370,14 @@  void btrfs_discard_update_discardable(struct btrfs_block_group *block_group,
 		ctl->discardable_extents[BTRFS_STAT_PREV] =
 			ctl->discardable_extents[BTRFS_STAT_CURR];
 	}
+
+	bytes_delta = (ctl->discardable_bytes[BTRFS_STAT_CURR] -
+		       ctl->discardable_bytes[BTRFS_STAT_PREV]);
+	if (bytes_delta) {
+		atomic64_add(bytes_delta, &discard_ctl->discardable_bytes);
+		ctl->discardable_bytes[BTRFS_STAT_PREV] =
+			ctl->discardable_bytes[BTRFS_STAT_CURR];
+	}
 }
 
 /**
@@ -460,6 +469,7 @@  void btrfs_discard_init(struct btrfs_fs_info *fs_info)
 		INIT_LIST_HEAD(&discard_ctl->discard_list[i]);
 
 	atomic_set(&discard_ctl->discardable_extents, 0);
+	atomic64_set(&discard_ctl->discardable_bytes, 0);
 }
 
 void btrfs_discard_cleanup(struct btrfs_fs_info *fs_info)
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index b012be2b2213..c0a08c8df3dd 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -820,9 +820,11 @@  static int __load_free_space_cache(struct btrfs_root *root, struct inode *inode,
 		if (ret)
 			goto free_cache;
 		e->bitmap_extents = count_bitmap_extents(ctl, e);
-		if (!btrfs_free_space_trimmed(e))
+		if (!btrfs_free_space_trimmed(e)) {
 			ctl->discardable_extents[BTRFS_STAT_CURR] +=
 				e->bitmap_extents;
+			ctl->discardable_bytes[BTRFS_STAT_CURR] += e->bytes;
+		}
 	}
 
 	io_ctl_drop_pages(&io_ctl);
@@ -1644,8 +1646,10 @@  __unlink_free_space(struct btrfs_free_space_ctl *ctl,
 	rb_erase(&info->offset_index, &ctl->free_space_offset);
 	ctl->free_extents--;
 
-	if (!info->bitmap && !btrfs_free_space_trimmed(info))
+	if (!info->bitmap && !btrfs_free_space_trimmed(info)) {
 		ctl->discardable_extents[BTRFS_STAT_CURR]--;
+		ctl->discardable_bytes[BTRFS_STAT_CURR] -= info->bytes;
+	}
 }
 
 static void unlink_free_space(struct btrfs_free_space_ctl *ctl,
@@ -1666,8 +1670,10 @@  static int link_free_space(struct btrfs_free_space_ctl *ctl,
 	if (ret)
 		return ret;
 
-	if (!info->bitmap && !btrfs_free_space_trimmed(info))
+	if (!info->bitmap && !btrfs_free_space_trimmed(info)) {
 		ctl->discardable_extents[BTRFS_STAT_CURR]++;
+		ctl->discardable_bytes[BTRFS_STAT_CURR] += info->bytes;
+	}
 
 	ctl->free_space += info->bytes;
 	ctl->free_extents++;
@@ -1746,8 +1752,10 @@  static inline void __bitmap_clear_bits(struct btrfs_free_space_ctl *ctl,
 		extent_delta++;
 
 	info->bitmap_extents += extent_delta;
-	if (!btrfs_free_space_trimmed(info))
+	if (!btrfs_free_space_trimmed(info)) {
 		ctl->discardable_extents[BTRFS_STAT_CURR] += extent_delta;
+		ctl->discardable_bytes[BTRFS_STAT_CURR] -= bytes;
+	}
 }
 
 static void bitmap_clear_bits(struct btrfs_free_space_ctl *ctl,
@@ -1782,8 +1790,10 @@  static void bitmap_set_bits(struct btrfs_free_space_ctl *ctl,
 		extent_delta--;
 
 	info->bitmap_extents += extent_delta;
-	if (!btrfs_free_space_trimmed(info))
+	if (!btrfs_free_space_trimmed(info)) {
 		ctl->discardable_extents[BTRFS_STAT_CURR] += extent_delta;
+		ctl->discardable_bytes[BTRFS_STAT_CURR] += bytes;
+	}
 }
 
 /*
@@ -2054,9 +2064,11 @@  static u64 add_bytes_to_bitmap(struct btrfs_free_space_ctl *ctl,
 	 * whole bitmap untrimmed if at any point we add untrimmed regions.
 	 */
 	if (trim_state == BTRFS_TRIM_STATE_UNTRIMMED) {
-		if (btrfs_free_space_trimmed(info))
+		if (btrfs_free_space_trimmed(info)) {
 			ctl->discardable_extents[BTRFS_STAT_CURR] +=
 				info->bitmap_extents;
+			ctl->discardable_bytes[BTRFS_STAT_CURR] += info->bytes;
+		}
 		info->trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
 	}
 
@@ -2691,15 +2703,21 @@  __btrfs_return_cluster_to_free_space(
 		bitmap = (entry->bitmap != NULL);
 		if (!bitmap) {
 			/* merging treats extents as if they were new */
-			if (!btrfs_free_space_trimmed(entry))
+			if (!btrfs_free_space_trimmed(entry)) {
 				ctl->discardable_extents[BTRFS_STAT_CURR]--;
+				ctl->discardable_bytes[BTRFS_STAT_CURR] -=
+					entry->bytes;
+			}
 
 			try_merge_free_space(ctl, entry, false);
 			steal_from_bitmap(ctl, entry, false);
 
 			/* as we insert directly, update these statistics */
-			if (!btrfs_free_space_trimmed(entry))
+			if (!btrfs_free_space_trimmed(entry)) {
 				ctl->discardable_extents[BTRFS_STAT_CURR]++;
+				ctl->discardable_bytes[BTRFS_STAT_CURR] +=
+					entry->bytes;
+			}
 		}
 		tree_insert_offset(&ctl->free_space_offset,
 				   entry->offset, &entry->offset_index, bitmap);
@@ -2990,6 +3008,8 @@  u64 btrfs_alloc_from_cluster(struct btrfs_block_group *block_group,
 	spin_lock(&ctl->tree_lock);
 
 	ctl->free_space -= bytes;
+	if (!entry->bitmap && !btrfs_free_space_trimmed(entry))
+		ctl->discardable_bytes[BTRFS_STAT_CURR] -= bytes;
 	if (entry->bytes == 0) {
 		ctl->free_extents--;
 		if (entry->bitmap) {
@@ -3495,9 +3515,11 @@  static void reset_trimming_bitmap(struct btrfs_free_space_ctl *ctl, u64 offset)
 
 	entry = tree_search_offset(ctl, offset, 1, 0);
 	if (entry) {
-		if (btrfs_free_space_trimmed(entry))
+		if (btrfs_free_space_trimmed(entry)) {
 			ctl->discardable_extents[BTRFS_STAT_CURR] +=
 				entry->bitmap_extents;
+			ctl->discardable_bytes[BTRFS_STAT_CURR] += entry->bytes;
+		}
 		entry->trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
 	}
 
@@ -3511,6 +3533,7 @@  static void end_trimming_bitmap(struct btrfs_free_space_ctl *ctl,
 		entry->trim_state = BTRFS_TRIM_STATE_TRIMMED;
 		ctl->discardable_extents[BTRFS_STAT_CURR] -=
 			entry->bitmap_extents;
+		ctl->discardable_bytes[BTRFS_STAT_CURR] -= entry->bytes;
 	}
 }
 
diff --git a/fs/btrfs/free-space-cache.h b/fs/btrfs/free-space-cache.h
index 56235391a04a..b61b52eeaaf3 100644
--- a/fs/btrfs/free-space-cache.h
+++ b/fs/btrfs/free-space-cache.h
@@ -52,6 +52,7 @@  struct btrfs_free_space_ctl {
 	int unit;
 	u64 start;
 	s32 discardable_extents[BTRFS_STAT_NR_ENTRIES];
+	s64 discardable_bytes[BTRFS_STAT_NR_ENTRIES];
 	const struct btrfs_free_space_op *op;
 	void *private;
 	struct mutex cache_writeout_mutex;
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index 220d77c38363..07098f6d62bd 100644
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -355,8 +355,20 @@  static ssize_t btrfs_discardable_extents_show(struct kobject *kobj,
 }
 BTRFS_ATTR(discard, discardable_extents, btrfs_discardable_extents_show);
 
+static ssize_t btrfs_discardable_bytes_show(struct kobject *kobj,
+					    struct kobj_attribute *a,
+					    char *buf)
+{
+	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
+
+	return snprintf(buf, PAGE_SIZE, "%lld\n",
+			atomic64_read(&fs_info->discard_ctl.discardable_bytes));
+}
+BTRFS_ATTR(discard, discardable_bytes, btrfs_discardable_bytes_show);
+
 static const struct attribute *discard_debug_attrs[] = {
 	BTRFS_ATTR_PTR(discard, discardable_extents),
+	BTRFS_ATTR_PTR(discard, discardable_bytes),
 	NULL,
 };