From 963d678b0f7649300e3a67f2513ca9d830c6e303 Mon Sep 17 00:00:00 2001 From: Miao Xie Date: Tue, 29 Jan 2013 10:10:51 +0000 Subject: Btrfs: use percpu counter for fs_info->delalloc_bytes fs_info->delalloc_bytes is accessed very frequently, so use percpu counter instead of the u64 variant for it to reduce the lock contention. This patch also fixed the problem that we access the variant without the lock protection.At worst, we would not flush the delalloc inodes, and just return ENOSPC error when we still have some free space in the fs. Signed-off-by: Miao Xie Signed-off-by: Josef Bacik --- fs/btrfs/extent-tree.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'fs/btrfs/extent-tree.c') diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 174c4d5c692c..115d1646bf50 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -3760,7 +3760,8 @@ static void shrink_delalloc(struct btrfs_root *root, u64 to_reclaim, u64 orig, space_info = block_rsv->space_info; smp_mb(); - delalloc_bytes = root->fs_info->delalloc_bytes; + delalloc_bytes = percpu_counter_sum_positive( + &root->fs_info->delalloc_bytes); if (delalloc_bytes == 0) { if (trans) return; @@ -3799,7 +3800,8 @@ static void shrink_delalloc(struct btrfs_root *root, u64 to_reclaim, u64 orig, break; } smp_mb(); - delalloc_bytes = root->fs_info->delalloc_bytes; + delalloc_bytes = percpu_counter_sum_positive( + &root->fs_info->delalloc_bytes); } } -- cgit v1.2.3