From 7ef70b4d9987a78d39c4e40a02093493333e5408 Mon Sep 17 00:00:00 2001 From: David Sterba Date: Thu, 2 Mar 2017 18:54:52 +0100 Subject: [PATCH] btrfs: preallocate radix tree node for global readahead tree We can preallocate the node so insertion does not have to do that under the lock. The GFP flags for the global radix tree are initialized to GFP_NOFS & ~__GFP_DIRECT_RECLAIM but we can use GFP_KERNEL, because readahead is optional and not on any critical writeout path. Reviewed-by: Liu Bo Signed-off-by: David Sterba --- fs/btrfs/disk-io.c | 2 +- fs/btrfs/reada.c | 7 +++++++ 2 files changed, 8 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index bd415e1dd114..12eba54877c2 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -2693,7 +2693,7 @@ int open_ctree(struct super_block *sb, fs_info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL; fs_info->avg_delayed_ref_runtime = NSEC_PER_SEC >> 6; /* div by 64 */ /* readahead state */ - INIT_RADIX_TREE(&fs_info->reada_tree, GFP_NOFS & ~__GFP_DIRECT_RECLAIM); + INIT_RADIX_TREE(&fs_info->reada_tree, GFP_KERNEL); spin_lock_init(&fs_info->reada_lock); fs_info->thread_pool_size = min_t(unsigned long, diff --git a/fs/btrfs/reada.c b/fs/btrfs/reada.c index fdae8ca79401..a7fa4a5cb296 100644 --- a/fs/btrfs/reada.c +++ b/fs/btrfs/reada.c @@ -393,6 +393,10 @@ static struct reada_extent *reada_find_extent(struct btrfs_fs_info *fs_info, goto error; } + ret = radix_tree_preload(GFP_KERNEL); + if (ret) + goto error; + /* insert extent in reada_tree + all per-device trees, all or nothing */ btrfs_dev_replace_lock(&fs_info->dev_replace, 0); spin_lock(&fs_info->reada_lock); @@ -402,13 +406,16 @@ static struct reada_extent *reada_find_extent(struct btrfs_fs_info *fs_info, re_exist->refcnt++; spin_unlock(&fs_info->reada_lock); btrfs_dev_replace_unlock(&fs_info->dev_replace, 0); + radix_tree_preload_end(); goto error; } if (ret) { spin_unlock(&fs_info->reada_lock); btrfs_dev_replace_unlock(&fs_info->dev_replace, 0); + radix_tree_preload_end(); goto error; } + radix_tree_preload_end(); prev_dev = NULL; dev_replace_is_ongoing = btrfs_dev_replace_is_ongoing( &fs_info->dev_replace); -- 2.20.1