Re: [PATCH 07/12] mm, page_alloc: Distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd

[Mel Gorman <mgorman@techsingularity.net>]

On Mon, Aug 24, 2015 at 01:09:46PM +0100, Mel Gorman wrote:
> diff --git a/lib/radix-tree.c b/lib/radix-tree.c
> index f9ebe1c82060..c3775ee46cd6 100644
> --- a/lib/radix-tree.c
> +++ b/lib/radix-tree.c
> @@ -188,7 +188,7 @@ radix_tree_node_alloc(struct radix_tree_root *root)
>  	 * preloading in the interrupt anyway as all the allocations have to
>  	 * be atomic. So just do normal allocation when in interrupt.
>  	 */
> -	if (!(gfp_mask & __GFP_WAIT) && !in_interrupt()) {
> +	if (!gfpflags_allow_blocking(gfp_mask) && !in_interrupt()) {
>  		struct radix_tree_preload *rtp;
>  
>  		/*
> @@ -249,7 +249,7 @@ radix_tree_node_free(struct radix_tree_node *node)
>   * with preemption not disabled.
>   *
>   * To make use of this facility, the radix tree must be initialised without
> - * __GFP_WAIT being passed to INIT_RADIX_TREE().
> + * __GFP_DIRECT_RECLAIM being passed to INIT_RADIX_TREE().
>   */
>  static int __radix_tree_preload(gfp_t gfp_mask)
>  {
> @@ -286,12 +286,12 @@ static int __radix_tree_preload(gfp_t gfp_mask)
>   * with preemption not disabled.
>   *
>   * To make use of this facility, the radix tree must be initialised without
> - * __GFP_WAIT being passed to INIT_RADIX_TREE().
> + * __GFP_DIRECT_RECLAIM being passed to INIT_RADIX_TREE().
>   */
>  int radix_tree_preload(gfp_t gfp_mask)
>  {
>  	/* Warn on non-sensical use... */
> -	WARN_ON_ONCE(!(gfp_mask & __GFP_WAIT));
> +	WARN_ON_ONCE(gfpflags_allow_blocking(gfp_mask));
>  	return __radix_tree_preload(gfp_mask);
>  }
>  EXPORT_SYMBOL(radix_tree_preload);

This was a last minute conversion related to fixing up direct usages of
__GFP_DIRECT_RECLAIM that is obviously wrong. It needs a

diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index c3775ee46cd6..fcf5d98574ce 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -291,7 +291,7 @@ static int __radix_tree_preload(gfp_t gfp_mask)
 int radix_tree_preload(gfp_t gfp_mask)
 {
 	/* Warn on non-sensical use... */
-	WARN_ON_ONCE(gfpflags_allow_blocking(gfp_mask));
+	WARN_ON_ONCE(!gfpflags_allow_blocking(gfp_mask));
 	return __radix_tree_preload(gfp_mask);
 }
 EXPORT_SYMBOL(radix_tree_preload);

-- 
Mel Gorman
SUSE Labs