[1/7] btrfs: preallocate radix tree node for readahead
diff mbox

Message ID 81148cc21c03374082730036fe9c35f3072bd173.1489593696.git.dsterba@suse.com
State New
Headers show

Commit Message

David Sterba March 15, 2017, 4:02 p.m. UTC
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.

Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/reada.c   | 7 +++++++
 fs/btrfs/volumes.c | 2 +-
 2 files changed, 8 insertions(+), 1 deletion(-)

Comments

Liu Bo March 20, 2017, 8:40 p.m. UTC | #1
On Wed, Mar 15, 2017 at 05:02:23PM +0100, David Sterba wrote:
> 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 <bo.li.liu@oracle.com>

Thanks,

-liubo
> Signed-off-by: David Sterba <dsterba@suse.com>
> ---
>  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 e88bca87f5d2..fdae8ca79401 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 73d56eef5e60..f158b8657ae3 100644
> --- a/fs/btrfs/volumes.c
> +++ b/fs/btrfs/volumes.c
> @@ -247,7 +247,7 @@ 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;
> -- 
> 2.12.0
> 
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Patch
diff mbox

diff --git a/fs/btrfs/reada.c b/fs/btrfs/reada.c
index e88bca87f5d2..fdae8ca79401 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 73d56eef5e60..f158b8657ae3 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -247,7 +247,7 @@  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;