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From: Dennis Zhou <dennis@kernel.org>
To: David Sterba <dsterba@suse.com>, Chris Mason <clm@fb.com>,
	Josef Bacik <josef@toxicpanda.com>,
	Omar Sandoval <osandov@osandov.com>
Cc: kernel-team@fb.com, linux-btrfs@vger.kernel.org,
	Dennis Zhou <dennis@kernel.org>
Subject: [PATCH 19/22] btrfs: keep track of discard reuse stats
Date: Wed, 23 Oct 2019 18:53:13 -0400
Message-ID: <ae43bf66f7747044182068524114c6680ae68854.1571865775.git.dennis@kernel.org> (raw)
In-Reply-To: <cover.1571865774.git.dennis@kernel.org>
In-Reply-To: <cover.1571865774.git.dennis@kernel.org>

Keep track of how much we are discarding and how often we are reusing
with async discard.

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/ctree.h            |  3 +++
 fs/btrfs/discard.c          |  7 +++++++
 fs/btrfs/free-space-cache.c | 14 ++++++++++++++
 fs/btrfs/sysfs.c            | 36 ++++++++++++++++++++++++++++++++++++
 4 files changed, 60 insertions(+)

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 57cfc0e11c53..1bf016f8a3d8 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -472,6 +472,9 @@ struct btrfs_discard_ctl {
 	u32 delay;
 	u32 iops_limit;
 	u64 bps_limit;
+	u64 discard_extent_bytes;
+	u64 discard_bitmap_bytes;
+	atomic64_t discard_bytes_saved;
 };
 
 /* delayed seq elem */
diff --git a/fs/btrfs/discard.c b/fs/btrfs/discard.c
index be5a4439ceb0..f95e437d7629 100644
--- a/fs/btrfs/discard.c
+++ b/fs/btrfs/discard.c
@@ -406,11 +406,15 @@ static void btrfs_discard_workfn(struct work_struct *work)
 					       cache->discard_cursor,
 					       btrfs_block_group_end(cache),
 					       minlen, maxlen, true);
+		WRITE_ONCE(discard_ctl->discard_bitmap_bytes,
+			   discard_ctl->discard_bitmap_bytes + trimmed);
 	} else {
 		btrfs_trim_block_group_extents(cache, &trimmed,
 					       cache->discard_cursor,
 					       btrfs_block_group_end(cache),
 					       minlen, true);
+		WRITE_ONCE(discard_ctl->discard_extent_bytes,
+			   discard_ctl->discard_extent_bytes + trimmed);
 	}
 
 	discard_ctl->prev_discard = trimmed;
@@ -614,6 +618,9 @@ void btrfs_discard_init(struct btrfs_fs_info *fs_info)
 	discard_ctl->delay = BTRFS_DISCARD_MAX_DELAY;
 	discard_ctl->iops_limit = BTRFS_DISCARD_MAX_IOPS;
 	discard_ctl->bps_limit = 0;
+	discard_ctl->discard_extent_bytes = 0;
+	discard_ctl->discard_bitmap_bytes = 0;
+	atomic64_set(&discard_ctl->discard_bytes_saved, 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 dc632afe5f61..29d3e21ba7fd 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -2817,6 +2817,8 @@ u64 btrfs_find_space_for_alloc(struct btrfs_block_group_cache *block_group,
 			       u64 *max_extent_size)
 {
 	struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
+	struct btrfs_discard_ctl *discard_ctl =
+					&block_group->fs_info->discard_ctl;
 	struct btrfs_free_space *entry = NULL;
 	u64 bytes_search = bytes + empty_size;
 	u64 ret = 0;
@@ -2833,6 +2835,10 @@ u64 btrfs_find_space_for_alloc(struct btrfs_block_group_cache *block_group,
 	ret = offset;
 	if (entry->bitmap) {
 		bitmap_clear_bits(ctl, entry, offset, bytes);
+
+		if (!btrfs_free_space_trimmed(entry))
+			atomic64_add(bytes, &discard_ctl->discard_bytes_saved);
+
 		if (!entry->bytes)
 			free_bitmap(ctl, entry);
 	} else {
@@ -2841,6 +2847,9 @@ u64 btrfs_find_space_for_alloc(struct btrfs_block_group_cache *block_group,
 		align_gap = entry->offset;
 		align_gap_trim_state = entry->trim_state;
 
+		if (!btrfs_free_space_trimmed(entry))
+			atomic64_add(bytes, &discard_ctl->discard_bytes_saved);
+
 		entry->offset = offset + bytes;
 		WARN_ON(entry->bytes < bytes + align_gap_len);
 
@@ -2945,6 +2954,8 @@ u64 btrfs_alloc_from_cluster(struct btrfs_block_group_cache *block_group,
 			     u64 min_start, u64 *max_extent_size)
 {
 	struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
+	struct btrfs_discard_ctl *discard_ctl =
+					&block_group->fs_info->discard_ctl;
 	struct btrfs_free_space *entry = NULL;
 	struct rb_node *node;
 	u64 ret = 0;
@@ -3009,6 +3020,9 @@ u64 btrfs_alloc_from_cluster(struct btrfs_block_group_cache *block_group,
 
 	spin_lock(&ctl->tree_lock);
 
+	if (!btrfs_free_space_trimmed(entry))
+		atomic64_add(bytes, &discard_ctl->discard_bytes_saved);
+
 	ctl->free_space -= bytes;
 	if (!entry->bitmap && !btrfs_free_space_trimmed(entry))
 		ctl->discardable_bytes[BTRFS_STAT_CURR] -= bytes;
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index c441603b7da1..a00e260ead53 100644
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -431,12 +431,48 @@ static ssize_t btrfs_discard_max_discard_size_store(struct kobject *kobj,
 BTRFS_ATTR_RW(discard, max_discard_size, btrfs_discard_max_discard_size_show,
 	      btrfs_discard_max_discard_size_store);
 
+static ssize_t btrfs_discard_extent_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",
+			READ_ONCE(fs_info->discard_ctl.discard_extent_bytes));
+}
+BTRFS_ATTR(discard, discard_extent_bytes, btrfs_discard_extent_bytes_show);
+
+static ssize_t btrfs_discard_bitmap_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",
+			READ_ONCE(fs_info->discard_ctl.discard_bitmap_bytes));
+}
+BTRFS_ATTR(discard, discard_bitmap_bytes, btrfs_discard_bitmap_bytes_show);
+
+static ssize_t btrfs_discard_bytes_saved_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.discard_bytes_saved));
+}
+BTRFS_ATTR(discard, discard_bytes_saved, btrfs_discard_bytes_saved_show);
+
 static const struct attribute *discard_attrs[] = {
 	BTRFS_ATTR_PTR(discard, discardable_extents),
 	BTRFS_ATTR_PTR(discard, discardable_bytes),
 	BTRFS_ATTR_PTR(discard, iops_limit),
 	BTRFS_ATTR_PTR(discard, bps_limit),
 	BTRFS_ATTR_PTR(discard, max_discard_size),
+	BTRFS_ATTR_PTR(discard, discard_extent_bytes),
+	BTRFS_ATTR_PTR(discard, discard_bitmap_bytes),
+	BTRFS_ATTR_PTR(discard, discard_bytes_saved),
 	NULL,
 };
 
-- 
2.17.1


  parent reply index

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-23 22:52 [PATCH v2 00/22] btrfs: async discard support Dennis Zhou
2019-10-23 22:52 ` [PATCH 01/22] bitmap: genericize percpu bitmap region iterators Dennis Zhou
2019-10-23 22:52 ` [PATCH 02/22] btrfs: rename DISCARD opt to DISCARD_SYNC Dennis Zhou
2019-10-23 22:52 ` [PATCH 03/22] btrfs: keep track of which extents have been discarded Dennis Zhou
2019-11-08 19:05   ` Josef Bacik
2019-11-11 17:20     ` Dennis Zhou
2019-10-23 22:52 ` [PATCH 04/22] btrfs: keep track of cleanliness of the bitmap Dennis Zhou
2019-11-08 19:12   ` Josef Bacik
2019-10-23 22:52 ` [PATCH 05/22] btrfs: add the beginning of async discard, discard workqueue Dennis Zhou
2019-11-11 18:49   ` David Sterba
2019-10-23 22:53 ` [PATCH 06/22] btrfs: handle empty block_group removal Dennis Zhou
2019-11-08 19:19   ` Josef Bacik
2019-10-23 22:53 ` [PATCH 07/22] btrfs: discard one region at a time in async discard Dennis Zhou
2019-11-08 19:27   ` Josef Bacik
2019-10-23 22:53 ` [PATCH 08/22] btrfs: add removal calls for sysfs debug/ Dennis Zhou
2019-11-08 19:28   ` Josef Bacik
2019-10-23 22:53 ` [PATCH 09/22] btrfs: make UUID/debug have its own kobject Dennis Zhou
2019-11-08 19:29   ` Josef Bacik
2019-10-23 22:53 ` [PATCH 10/22] btrfs: add discard sysfs directory Dennis Zhou
2019-11-08 19:29   ` Josef Bacik
2019-10-23 22:53 ` [PATCH 11/22] btrfs: track discardable extents for async discard Dennis Zhou
2019-10-23 22:53 ` [PATCH 12/22] btrfs: keep track of discardable_bytes Dennis Zhou
2019-11-08 19:31   ` Josef Bacik
2019-10-23 22:53 ` [PATCH 13/22] btrfs: calculate discard delay based on number of extents Dennis Zhou
2019-10-23 22:53 ` [PATCH 14/22] btrfs: add bps discard rate limit Dennis Zhou
2019-11-08 19:41   ` Josef Bacik
2019-11-15 17:28     ` David Sterba
2019-10-23 22:53 ` [PATCH 15/22] btrfs: limit max discard size for async discard Dennis Zhou
2019-10-23 22:53 ` [PATCH 16/22] btrfs: make max async discard size tunable Dennis Zhou
2019-10-23 22:53 ` [PATCH 17/22] btrfs: have multiple discard lists Dennis Zhou
2019-11-08 19:44   ` Josef Bacik
2019-10-23 22:53 ` [PATCH 18/22] btrfs: only keep track of data extents for async discard Dennis Zhou
2019-11-08 19:46   ` Josef Bacik
2019-11-08 20:14     ` Dennis Zhou
2019-11-15 17:31       ` David Sterba
2019-10-23 22:53 ` Dennis Zhou [this message]
2019-10-23 22:53 ` [PATCH 20/22] btrfs: add async discard header Dennis Zhou
2019-10-23 22:53 ` [PATCH 21/22] btrfs: increase the metadata allowance for the free_space_cache Dennis Zhou
2019-10-23 22:53 ` [PATCH 22/22] btrfs: make smaller extents more likely to go into bitmaps Dennis Zhou
2019-11-15 17:40 ` [PATCH v2 00/22] btrfs: async discard support David Sterba
2019-11-20 21:50 [PATCH v3 " Dennis Zhou
2019-11-20 21:51 ` [PATCH 19/22] btrfs: keep track of discard reuse stats Dennis Zhou
2019-11-25 19:46 [PATCH v4 00/22] btrfs: async discard support Dennis Zhou
2019-11-25 19:46 ` [PATCH 19/22] btrfs: keep track of discard reuse stats Dennis Zhou

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