mm: honor PF_MEMALLOC_PIN for all movable pages

PF_MEMALLOC_PIN is only honored for CMA pages, extend this flag to work
for any allocations from ZONE_MOVABLE by removing __GFP_MOVABLE from
gfp_mask when this flag is passed in the current context.

Add is_pinnable_page() to return true if page is in a pinnable page.  A
pinnable page is not in ZONE_MOVABLE and not of MIGRATE_CMA type.

Link: https://lkml.kernel.org/r/20210215161349.246722-8-pasha.tatashin@soleen.com
Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: James Morris <jmorris@namei.org>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Tyler Hicks <tyhicks@linux.microsoft.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 9 insertions, 11 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 3c55eaafede1..81db38926266 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3859,16 +3859,13 @@ alloc_flags_nofragment(struct zone *zone, gfp_t gfp_mask)
 	return alloc_flags;
 }
 
-static inline unsigned int current_alloc_flags(gfp_t gfp_mask,
-					unsigned int alloc_flags)
+/* Must be called after current_gfp_context() which can change gfp_mask */
+static inline unsigned int gfp_to_alloc_flags_cma(gfp_t gfp_mask,
+						  unsigned int alloc_flags)
 {
 #ifdef CONFIG_CMA
-	unsigned int pflags = current->flags;
-
-	if (!(pflags & PF_MEMALLOC_PIN) &&
-	    gfp_migratetype(gfp_mask) == MIGRATE_MOVABLE)
+	if (gfp_migratetype(gfp_mask) == MIGRATE_MOVABLE)
 		alloc_flags |= ALLOC_CMA;
-
 #endif
 	return alloc_flags;
 }
@@ -4526,7 +4523,7 @@ gfp_to_alloc_flags(gfp_t gfp_mask)
 	} else if (unlikely(rt_task(current)) && !in_interrupt())
 		alloc_flags |= ALLOC_HARDER;
 
-	alloc_flags = current_alloc_flags(gfp_mask, alloc_flags);
+	alloc_flags = gfp_to_alloc_flags_cma(gfp_mask, alloc_flags);
 
 	return alloc_flags;
 }
@@ -4828,7 +4825,7 @@ retry:
 
 	reserve_flags = __gfp_pfmemalloc_flags(gfp_mask);
 	if (reserve_flags)
-		alloc_flags = current_alloc_flags(gfp_mask, reserve_flags);
+		alloc_flags = gfp_to_alloc_flags_cma(gfp_mask, reserve_flags);
 
 	/*
 	 * Reset the nodemask and zonelist iterators if memory policies can be
@@ -4997,7 +4994,7 @@ static inline bool prepare_alloc_pages(gfp_t gfp_mask, unsigned int order,
 	if (should_fail_alloc_page(gfp_mask, order))
 		return false;
 
-	*alloc_flags = current_alloc_flags(gfp_mask, *alloc_flags);
+	*alloc_flags = gfp_to_alloc_flags_cma(gfp_mask, *alloc_flags);
 
 	/* Dirty zone balancing only done in the fast path */
 	ac->spread_dirty_pages = (gfp_mask & __GFP_WRITE);
@@ -5184,7 +5181,8 @@ struct page *__alloc_pages(gfp_t gfp, unsigned int order, int preferred_nid,
 	 * Apply scoped allocation constraints. This is mainly about GFP_NOFS
 	 * resp. GFP_NOIO which has to be inherited for all allocation requests
 	 * from a particular context which has been marked by
-	 * memalloc_no{fs,io}_{save,restore}.
+	 * memalloc_no{fs,io}_{save,restore}. And PF_MEMALLOC_PIN which ensures
+	 * movable zones are not used during allocation.
 	 */
 	gfp = current_gfp_context(gfp);
 	alloc_gfp = gfp;