We use percpu_counter to reduce lock contention of frequently updated
counter. But the default 32 batch size is suitable only for inc/dec
update, not for sector size update. The end result is we still acquire
spin lock for every percpu_counter_add(). So use customized batch size
for total_bytes_pinned as we already done for dirty_metadata_bytes
and delalloc_bytes. Also we fix dirty_metadata_bytes to use
__percpu_counter_compare of customized batch so we get precise value of
dirty_metadata_bytes.
Signed-off-by: Ethan Lien <ethanl...@synology.com>
---
fs/btrfs/ctree.h | 1 +
fs/btrfs/disk-io.c | 10 ++++++----
fs/btrfs/extent-tree.c | 43 +++++++++++++++++++++++++++---------------
3 files changed, 35 insertions(+), 19 deletions(-)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 118346aceea9..df682a521635 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -422,6 +422,7 @@ struct btrfs_space_info {
* time the transaction commits.
*/
struct percpu_counter total_bytes_pinned;
+ s32 total_bytes_pinned_batch;
struct list_head list;
/* Protected by the spinlock 'lock'. */
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 205092dc9390..dfed08e70ec1 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -961,8 +961,9 @@ static int btree_writepages(struct address_space *mapping,
fs_info = BTRFS_I(mapping->host)->root->fs_info;
/* this is a bit racy, but that's ok */
- ret = percpu_counter_compare(&fs_info->dirty_metadata_bytes,
- BTRFS_DIRTY_METADATA_THRESH);
+ ret = __percpu_counter_compare(&fs_info->dirty_metadata_bytes,
+ BTRFS_DIRTY_METADATA_THRESH,
+ fs_info->dirty_metadata_batch);
if (ret < 0)
return 0;
}
@@ -4150,8 +4151,9 @@ static void __btrfs_btree_balance_dirty(struct
btrfs_fs_info *fs_info,
if (flush_delayed)
btrfs_balance_delayed_items(fs_info);
- ret = percpu_counter_compare(&fs_info->dirty_metadata_bytes,
- BTRFS_DIRTY_METADATA_THRESH);
+ ret = __percpu_counter_compare(&fs_info->dirty_metadata_bytes,
+ BTRFS_DIRTY_METADATA_THRESH,
+ fs_info->dirty_metadata_batch);
if (ret > 0) {
balance_dirty_pages_ratelimited(fs_info->btree_inode->i_mapping);
}
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 3d9fe58c0080..a067c047904c 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -758,7 +758,8 @@ static void add_pinned_bytes(struct btrfs_fs_info *fs_info,
s64 num_bytes,
space_info = __find_space_info(fs_info, flags);
ASSERT(space_info);
- percpu_counter_add(&space_info->total_bytes_pinned, num_bytes);
+ percpu_counter_add_batch(&space_info->total_bytes_pinned, num_bytes,
+ space_info->total_bytes_pinned_batch);
}
/*
@@ -2598,8 +2599,9 @@ static int cleanup_ref_head(struct btrfs_trans_handle
*trans,
flags = BTRFS_BLOCK_GROUP_METADATA;
space_info = __find_space_info(fs_info, flags);
ASSERT(space_info);
- percpu_counter_add(&space_info->total_bytes_pinned,
- -head->num_bytes);
+ percpu_counter_add_batch(&space_info->total_bytes_pinned,
+ -head->num_bytes,
+ space_info->total_bytes_pinned_batch);
if (head->is_data) {
spin_lock(&delayed_refs->lock);
@@ -4035,6 +4037,10 @@ static int create_space_info(struct btrfs_fs_info *info,
u64 flags)
INIT_LIST_HEAD(&space_info->ro_bgs);
INIT_LIST_HEAD(&space_info->tickets);
INIT_LIST_HEAD(&space_info->priority_tickets);
+ if (flags & BTRFS_BLOCK_GROUP_DATA)
+ space_info->total_bytes_pinned_batch = info->delalloc_batch;
+ else
+ space_info->total_bytes_pinned_batch =
info->dirty_metadata_batch;
ret = kobject_init_and_add(&space_info->kobj, &space_info_ktype,
info->space_info_kobj, "%s",
@@ -4309,9 +4315,10 @@ int btrfs_alloc_data_chunk_ondemand(struct btrfs_inode
*inode, u64 bytes)
* allocation, and no removed chunk in current transaction,
* don't bother committing the transaction.
*/
- have_pinned_space = percpu_counter_compare(
+ have_pinned_space = __percpu_counter_compare(
&data_sinfo->total_bytes_pinned,
- used + bytes - data_sinfo->total_bytes);
+ used + bytes - data_sinfo->total_bytes,
+ data_sinfo->total_bytes_pinned_batch);
spin_unlock(&data_sinfo->lock);
/* commit the current transaction and try again */
@@ -4912,8 +4919,9 @@ static int may_commit_transaction(struct btrfs_fs_info
*fs_info,
return 0;
/* See if there is enough pinned space to make this reservation */
- if (percpu_counter_compare(&space_info->total_bytes_pinned,
- bytes) >= 0)
+ if (__percpu_counter_compare(&space_info->total_bytes_pinned,
+ bytes,
+ space_info->total_bytes_pinned_batch) >= 0)
goto commit;
/*
@@ -4930,8 +4938,9 @@ static int may_commit_transaction(struct btrfs_fs_info
*fs_info,
bytes -= delayed_rsv->size;
spin_unlock(&delayed_rsv->lock);
- if (percpu_counter_compare(&space_info->total_bytes_pinned,
- bytes) < 0) {
+ if (__percpu_counter_compare(&space_info->total_bytes_pinned,
+ bytes,
+ space_info->total_bytes_pinned_batch) < 0) {
return -ENOSPC;
}
@@ -6268,8 +6277,9 @@ static int update_block_group(struct btrfs_trans_handle
*trans,
trace_btrfs_space_reservation(info, "pinned",
cache->space_info->flags,
num_bytes, 1);
-
percpu_counter_add(&cache->space_info->total_bytes_pinned,
- num_bytes);
+
percpu_counter_add_batch(&cache->space_info->total_bytes_pinned,
+ num_bytes,
+
cache->space_info->total_bytes_pinned_batch);
set_extent_dirty(info->pinned_extents,
bytenr, bytenr + num_bytes - 1,
GFP_NOFS | __GFP_NOFAIL);
@@ -6347,7 +6357,8 @@ static int pin_down_extent(struct btrfs_fs_info *fs_info,
trace_btrfs_space_reservation(fs_info, "pinned",
cache->space_info->flags, num_bytes, 1);
- percpu_counter_add(&cache->space_info->total_bytes_pinned, num_bytes);
+ percpu_counter_add_batch(&cache->space_info->total_bytes_pinned,
+ num_bytes, cache->space_info->total_bytes_pinned_batch);
set_extent_dirty(fs_info->pinned_extents, bytenr,
bytenr + num_bytes - 1, GFP_NOFS | __GFP_NOFAIL);
return 0;
@@ -6711,7 +6722,8 @@ static int unpin_extent_range(struct btrfs_fs_info
*fs_info,
trace_btrfs_space_reservation(fs_info, "pinned",
space_info->flags, len, 0);
space_info->max_extent_size = 0;
- percpu_counter_add(&space_info->total_bytes_pinned, -len);
+ percpu_counter_add_batch(&space_info->total_bytes_pinned,
+ -len, space_info->total_bytes_pinned_batch);
if (cache->ro) {
space_info->bytes_readonly += len;
readonly = true;
@@ -10764,8 +10776,9 @@ void btrfs_delete_unused_bgs(struct btrfs_fs_info
*fs_info)
space_info->bytes_pinned -= block_group->pinned;
space_info->bytes_readonly += block_group->pinned;
- percpu_counter_add(&space_info->total_bytes_pinned,
- -block_group->pinned);
+ percpu_counter_add_batch(&space_info->total_bytes_pinned,
+ -block_group->pinned,
+ space_info->total_bytes_pinned_batch);
block_group->pinned = 0;
spin_unlock(&block_group->lock);
--
2.17.1
--
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