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>

2 files changed, 23 insertions, 1 deletions

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 1dbb53c44243..d0e628f511e4 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1141,6 +1141,11 @@ static inline bool is_zone_device_page(const struct page *page)
 }
 #endif
 
+static inline bool is_zone_movable_page(const struct page *page)
+{
+	return page_zonenum(page) == ZONE_MOVABLE;
+}
+
 #ifdef CONFIG_DEV_PAGEMAP_OPS
 void free_devmap_managed_page(struct page *page);
 DECLARE_STATIC_KEY_FALSE(devmap_managed_key);
@@ -1550,6 +1555,19 @@ static inline unsigned long page_to_section(const struct page *page)
 }
 #endif
 
+/* MIGRATE_CMA and ZONE_MOVABLE do not allow pin pages */
+#ifdef CONFIG_MIGRATION
+static inline bool is_pinnable_page(struct page *page)
+{
+	return !is_zone_movable_page(page) && !is_migrate_cma_page(page);
+}
+#else
+static inline bool is_pinnable_page(struct page *page)
+{
+	return true;
+}
+#endif
+
 static inline void set_page_zone(struct page *page, enum zone_type zone)
 {
 	page->flags &= ~(ZONES_MASK << ZONES_PGSHIFT);
diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h
index ae654819e8aa..e24b1fe348e3 100644
--- a/include/linux/sched/mm.h
+++ b/include/linux/sched/mm.h
@@ -151,12 +151,13 @@ static inline bool in_vfork(struct task_struct *tsk)
  * Applies per-task gfp context to the given allocation flags.
  * PF_MEMALLOC_NOIO implies GFP_NOIO
  * PF_MEMALLOC_NOFS implies GFP_NOFS
+ * PF_MEMALLOC_PIN  implies !GFP_MOVABLE
  */
 static inline gfp_t current_gfp_context(gfp_t flags)
 {
 	unsigned int pflags = READ_ONCE(current->flags);
 
-	if (unlikely(pflags & (PF_MEMALLOC_NOIO | PF_MEMALLOC_NOFS))) {
+	if (unlikely(pflags & (PF_MEMALLOC_NOIO | PF_MEMALLOC_NOFS | PF_MEMALLOC_PIN))) {
 		/*
 		 * NOIO implies both NOIO and NOFS and it is a weaker context
 		 * so always make sure it makes precedence
@@ -165,6 +166,9 @@ static inline gfp_t current_gfp_context(gfp_t flags)
 			flags &= ~(__GFP_IO | __GFP_FS);
 		else if (pflags & PF_MEMALLOC_NOFS)
 			flags &= ~__GFP_FS;
+
+		if (pflags & PF_MEMALLOC_PIN)
+			flags &= ~__GFP_MOVABLE;
 	}
 	return flags;
 }