mm cma: rename PF_MEMALLOC_NOCMA to PF_MEMALLOC_PIN

PF_MEMALLOC_NOCMA is used ot guarantee that the allocator will not
return pages that might belong to CMA region.  This is currently used
for long term gup to make sure that such pins are not going to be done
on any CMA pages.

When PF_MEMALLOC_NOCMA has been introduced we haven't realized that it
is focusing on CMA pages too much and that there is larger class of
pages that need the same treatment.  MOVABLE zone cannot contain any
long term pins as well so it makes sense to reuse and redefine this flag
for that usecase as well.  Rename the flag to PF_MEMALLOC_PIN which
defines an allocation context which can only get pages suitable for
long-term pins.

Also rename: memalloc_nocma_save()/memalloc_nocma_restore to
memalloc_pin_save()/memalloc_pin_restore() and make the new functions
common.

[rppt@linux.ibm.com: fix renaming of PF_MEMALLOC_NOCMA to PF_MEMALLOC_PIN]
Link: https://lkml.kernel.org/r/20210331163816.11517-1-rppt@kernel.org
Link: https://lkml.kernel.org/r/20210215161349.246722-6-pasha.tatashin@soleen.com
Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Mike Rapoport <rppt@linux.ibm.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: 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>

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 9c25c8e..d2c8813 100644 (file)
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1583,7 +1583,7 @@ extern struct pid *cad_pid;
 #define PF_SWAPWRITE           0x00800000      /* Allowed to write to swap */
 #define PF_NO_SETAFFINITY      0x04000000      /* Userland is not allowed to meddle with cpus_mask */
 #define PF_MCE_EARLY           0x08000000      /* Early kill for mce process policy */
-#define PF_MEMALLOC_NOCMA      0x10000000      /* All allocation request will have _GFP_MOVABLE cleared */
+#define PF_MEMALLOC_PIN                0x10000000      /* Allocation context constrained to zones which allow long term pinning. */
 #define PF_FREEZER_SKIP                0x40000000      /* Freezer should not count it as freezable */
 #define PF_SUSPEND_TASK                0x80000000      /* This thread called freeze_processes() and should not be frozen */
 

diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h
index 90b2a0b..ae65481 100644 (file)
--- a/include/linux/sched/mm.h
+++ b/include/linux/sched/mm.h
@@ -271,29 +271,18 @@ static inline void memalloc_noreclaim_restore(unsigned int flags)
        current->flags = (current->flags & ~PF_MEMALLOC) | flags;
 }
 
-#ifdef CONFIG_CMA
-static inline unsigned int memalloc_nocma_save(void)
+static inline unsigned int memalloc_pin_save(void)
 {
-       unsigned int flags = current->flags & PF_MEMALLOC_NOCMA;
+       unsigned int flags = current->flags & PF_MEMALLOC_PIN;
 
-       current->flags |= PF_MEMALLOC_NOCMA;
+       current->flags |= PF_MEMALLOC_PIN;
        return flags;
 }
 
-static inline void memalloc_nocma_restore(unsigned int flags)
+static inline void memalloc_pin_restore(unsigned int flags)
 {
-       current->flags = (current->flags & ~PF_MEMALLOC_NOCMA) | flags;
+       current->flags = (current->flags & ~PF_MEMALLOC_PIN) | flags;
 }
-#else
-static inline unsigned int memalloc_nocma_save(void)
-{
-       return 0;
-}
-
-static inline void memalloc_nocma_restore(unsigned int flags)
-{
-}
-#endif
 
 #ifdef CONFIG_MEMCG
 DECLARE_PER_CPU(struct mem_cgroup *, int_active_memcg);

diff --git a/mm/gup.c b/mm/gup.c
index 3a00f6a..a1eff7a 100644 (file)
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -1722,7 +1722,7 @@ static long __gup_longterm_locked(struct mm_struct *mm,
        long rc;
 
        if (gup_flags & FOLL_LONGTERM)
-               flags = memalloc_nocma_save();
+               flags = memalloc_pin_save();
 
        rc = __get_user_pages_locked(mm, start, nr_pages, pages, vmas, NULL,
                                     gup_flags);
@@ -1731,7 +1731,7 @@ static long __gup_longterm_locked(struct mm_struct *mm,
                if (rc > 0)
                        rc = check_and_migrate_cma_pages(mm, start, rc, pages,
                                                         vmas, gup_flags);
-               memalloc_nocma_restore(flags);
+               memalloc_pin_restore(flags);
        }
        return rc;
 }

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 533e5a2..60dc197 100644 (file)
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1079,11 +1079,11 @@ static void enqueue_huge_page(struct hstate *h, struct page *page)
 static struct page *dequeue_huge_page_node_exact(struct hstate *h, int nid)
 {
        struct page *page;
-       bool nocma = !!(current->flags & PF_MEMALLOC_NOCMA);
+       bool pin = !!(current->flags & PF_MEMALLOC_PIN);
 
        lockdep_assert_held(&hugetlb_lock);
        list_for_each_entry(page, &h->hugepage_freelists[nid], lru) {
-               if (nocma && is_migrate_cma_page(page))
+               if (pin && is_migrate_cma_page(page))
                        continue;
 
                if (PageHWPoison(page))

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index d12299c..c2fc6a6 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3865,8 +3865,8 @@ static inline unsigned int current_alloc_flags(gfp_t gfp_mask,
 #ifdef CONFIG_CMA
        unsigned int pflags = current->flags;
 
-       if (!(pflags & PF_MEMALLOC_NOCMA) &&
-                       gfp_migratetype(gfp_mask) == MIGRATE_MOVABLE)
+       if (!(pflags & PF_MEMALLOC_PIN) &&
+           gfp_migratetype(gfp_mask) == MIGRATE_MOVABLE)
                alloc_flags |= ALLOC_CMA;
 
 #endif