[Devel] [PATCH v4 13/25] Add a __GFP_SLABMEMCG flag

[Glauber Costa]

This flag is used to indicate to the callees that this allocation will be
serviced to the kernel. It is not supposed to be passed by the callers
of kmem_cache_alloc, but rather by the cache core itself.

CC: Christoph Lameter <cl at linux.com>
CC: Pekka Enberg <penberg at cs.helsinki.fi>
CC: Michal Hocko <mhocko at suse.cz>
CC: Kamezawa Hiroyuki <kamezawa.hiroyu at jp.fujitsu.com>
CC: Johannes Weiner <hannes at cmpxchg.org>
CC: Suleiman Souhlal <suleiman at google.com>
---
 include/linux/gfp.h |    8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index 581e74b..f904fe1 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -37,6 +37,9 @@ struct vm_area_struct;
 #define ___GFP_NO_KSWAPD	0x400000u
 #define ___GFP_OTHER_NODE	0x800000u
 #define ___GFP_WRITE		0x1000000u
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+#define ___GFP_SLABMEMCG	0x2000000u
+#endif
 
 /*
  * GFP bitmasks..
@@ -88,13 +91,16 @@ struct vm_area_struct;
 #define __GFP_OTHER_NODE ((__force gfp_t)___GFP_OTHER_NODE) /* On behalf of other node */
 #define __GFP_WRITE	((__force gfp_t)___GFP_WRITE)	/* Allocator intends to dirty page */
 
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+#define __GFP_SLABMEMCG	((__force gfp_t)___GFP_SLABMEMCG)/* Allocation comes from a memcg slab */
+#endif
 /*
  * This may seem redundant, but it's a way of annotating false positives vs.
  * allocations that simply cannot be supported (e.g. page tables).
  */
 #define __GFP_NOTRACK_FALSE_POSITIVE (__GFP_NOTRACK)
 
-#define __GFP_BITS_SHIFT 25	/* Room for N __GFP_FOO bits */
+#define __GFP_BITS_SHIFT 26	/* Room for N __GFP_FOO bits */
 #define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))
 
 /* This equals 0, but use constants in case they ever change */
-- 
1.7.10.2