From cc8385b59e17d489814d54d6a846aba7051fdea5 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 readahead We can preallocate the node so insertion does not have to do that under the lock. The GFP flags for the per-device radix tree are initialized to GFP_NOFS & ~__GFP_DIRECT_RECLAIM but we can use GFP_KERNEL, same as an allocation above anyway, but also because readahead is optional and not on any critical writeout path. Reviewed-by: Liu Bo Signed-off-by: David Sterba --- fs/btrfs/reada.c | 7 +++++++ fs/btrfs/volumes.c | 2 +- 2 files changed, 8 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/reada.c b/fs/btrfs/reada.c index e88bca8..fdae8ca 100644 --- a/fs/btrfs/reada.c +++ b/fs/btrfs/reada.c @@ -270,6 +270,12 @@ static struct reada_zone *reada_find_zone(struct btrfs_fs_info *fs_info, if (!zone) return NULL; + ret = radix_tree_preload(GFP_KERNEL); + if (ret) { + kfree(zone); + return NULL; + } + zone->start = start; zone->end = end; INIT_LIST_HEAD(&zone->list); @@ -299,6 +305,7 @@ static struct reada_zone *reada_find_zone(struct btrfs_fs_info *fs_info, zone = NULL; } spin_unlock(&fs_info->reada_lock); + radix_tree_preload_end(); return zone; } diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 13574f3..df50a63 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -252,7 +252,7 @@ static struct btrfs_device *__alloc_device(void) atomic_set(&dev->reada_in_flight, 0); atomic_set(&dev->dev_stats_ccnt, 0); btrfs_device_data_ordered_init(dev); - INIT_RADIX_TREE(&dev->reada_zones, GFP_NOFS & ~__GFP_DIRECT_RECLAIM); + INIT_RADIX_TREE(&dev->reada_zones, GFP_KERNEL); INIT_RADIX_TREE(&dev->reada_extents, GFP_NOFS & ~__GFP_DIRECT_RECLAIM); return dev; -- 2.7.4