mm, page_alloc: rename __GFP_WAIT to __GFP_RECLAIM

__GFP_WAIT was used to signal that the caller was in atomic context and
could not sleep.  Now it is possible to distinguish between true atomic
context and callers that are not willing to sleep.  The latter should
clear __GFP_DIRECT_RECLAIM so kswapd will still wake.  As clearing
__GFP_WAIT behaves differently, there is a risk that people will clear the
wrong flags.  This patch renames __GFP_WAIT to __GFP_RECLAIM to clearly
indicate what it does -- setting it allows all reclaim activity, clearing
them prevents it.

[akpm@linux-foundation.org: fix build]
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Lameter <cl@linux.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

6 files changed, 13 insertions, 12 deletions

diff --git a/mm/failslab.c b/mm/failslab.c
index 98fb490311eb..79171b4a5826 100644
--- a/mm/failslab.c
+++ b/mm/failslab.c
@@ -3,11 +3,11 @@
 
 static struct {
 	struct fault_attr attr;
-	bool ignore_gfp_wait;
+	bool ignore_gfp_reclaim;
 	bool cache_filter;
 } failslab = {
 	.attr = FAULT_ATTR_INITIALIZER,
-	.ignore_gfp_wait = true,
+	.ignore_gfp_reclaim = true,
 	.cache_filter = false,
 };
 
@@ -16,7 +16,7 @@ bool should_failslab(size_t size, gfp_t gfpflags, unsigned long cache_flags)
 	if (gfpflags & __GFP_NOFAIL)
 		return false;
 
-        if (failslab.ignore_gfp_wait && (gfpflags & __GFP_WAIT))
+	if (failslab.ignore_gfp_reclaim && (gfpflags & __GFP_RECLAIM))
 		return false;
 
 	if (failslab.cache_filter && !(cache_flags & SLAB_FAILSLAB))
@@ -42,7 +42,7 @@ static int __init failslab_debugfs_init(void)
 		return PTR_ERR(dir);
 
 	if (!debugfs_create_bool("ignore-gfp-wait", mode, dir,
-				&failslab.ignore_gfp_wait))
+				&failslab.ignore_gfp_reclaim))
 		goto fail;
 	if (!debugfs_create_bool("cache-filter", mode, dir,
 				&failslab.cache_filter))
diff --git a/mm/filemap.c b/mm/filemap.c
index 58e04e26f996..6ef3674c0763 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2713,7 +2713,7 @@ EXPORT_SYMBOL(generic_file_write_iter);
  * page is known to the local caching routines.
  *
  * The @gfp_mask argument specifies whether I/O may be performed to release
- * this page (__GFP_IO), and whether the call may block (__GFP_WAIT & __GFP_FS).
+ * this page (__GFP_IO), and whether the call may block (__GFP_RECLAIM & __GFP_FS).
  *
  */
 int try_to_release_page(struct page *page, gfp_t gfp_mask)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index f5c08b46fef8..9812d4618651 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -786,7 +786,7 @@ static int __do_huge_pmd_anonymous_page(struct mm_struct *mm,
 
 static inline gfp_t alloc_hugepage_gfpmask(int defrag, gfp_t extra_gfp)
 {
-	return (GFP_TRANSHUGE & ~(defrag ? 0 : __GFP_WAIT)) | extra_gfp;
+	return (GFP_TRANSHUGE & ~(defrag ? 0 : __GFP_RECLAIM)) | extra_gfp;
 }
 
 /* Caller must hold page table lock. */
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 05374f09339c..a5470674a477 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2120,7 +2120,7 @@ done_restock:
 	/*
 	 * If the hierarchy is above the normal consumption range, schedule
 	 * reclaim on returning to userland.  We can perform reclaim here
-	 * if __GFP_WAIT but let's always punt for simplicity and so that
+	 * if __GFP_RECLAIM but let's always punt for simplicity and so that
 	 * GFP_KERNEL can consistently be used during reclaim.  @memcg is
 	 * not recorded as it most likely matches current's and won't
 	 * change in the meantime.  As high limit is checked again before
diff --git a/mm/migrate.c b/mm/migrate.c
index e60379eb23f8..7890d0bb5e23 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1752,7 +1752,7 @@ int migrate_misplaced_transhuge_page(struct mm_struct *mm,
 		goto out_dropref;
 
 	new_page = alloc_pages_node(node,
-		(GFP_TRANSHUGE | __GFP_THISNODE) & ~__GFP_WAIT,
+		(GFP_TRANSHUGE | __GFP_THISNODE) & ~__GFP_RECLAIM,
 		HPAGE_PMD_ORDER);
 	if (!new_page)
 		goto out_fail;
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 70461f3e3378..1b373096b990 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2160,11 +2160,11 @@ static struct {
 	struct fault_attr attr;
 
 	bool ignore_gfp_highmem;
-	bool ignore_gfp_wait;
+	bool ignore_gfp_reclaim;
 	u32 min_order;
 } fail_page_alloc = {
 	.attr = FAULT_ATTR_INITIALIZER,
-	.ignore_gfp_wait = true,
+	.ignore_gfp_reclaim = true,
 	.ignore_gfp_highmem = true,
 	.min_order = 1,
 };
@@ -2183,7 +2183,8 @@ static bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
 		return false;
 	if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
 		return false;
-	if (fail_page_alloc.ignore_gfp_wait && (gfp_mask & __GFP_DIRECT_RECLAIM))
+	if (fail_page_alloc.ignore_gfp_reclaim &&
+			(gfp_mask & __GFP_DIRECT_RECLAIM))
 		return false;
 
 	return should_fail(&fail_page_alloc.attr, 1 << order);
@@ -2202,7 +2203,7 @@ static int __init fail_page_alloc_debugfs(void)
 		return PTR_ERR(dir);
 
 	if (!debugfs_create_bool("ignore-gfp-wait", mode, dir,
-				&fail_page_alloc.ignore_gfp_wait))
+				&fail_page_alloc.ignore_gfp_reclaim))
 		goto fail;
 	if (!debugfs_create_bool("ignore-gfp-highmem", mode, dir,
 				&fail_page_alloc.ignore_gfp_highmem))