From: Peter Zijlstra Subject: [PATCH 10/31] mm: __GFP_MEMALLOC Patch-mainline: not yet __GFP_MEMALLOC will allow the allocation to disregard the watermarks, much like PF_MEMALLOC. It allows one to pass along the memalloc state in object related allocation flags as opposed to task related flags, such as sk->sk_allocation. Signed-off-by: Peter Zijlstra Signed-off-by: Suresh Jayaraman --- include/linux/gfp.h | 4 +++- mm/page_alloc.c | 4 +++- 2 files changed, 6 insertions(+), 2 deletions(-) --- a/include/linux/gfp.h +++ b/include/linux/gfp.h @@ -23,6 +23,7 @@ struct vm_area_struct; #define ___GFP_REPEAT 0x400u #define ___GFP_NOFAIL 0x800u #define ___GFP_NORETRY 0x1000u +#define ___GFP_MEMALLOC 0x2000u #define ___GFP_COMP 0x4000u #define ___GFP_ZERO 0x8000u #define ___GFP_NOMEMALLOC 0x10000u @@ -73,6 +74,7 @@ struct vm_area_struct; #define __GFP_REPEAT ((__force gfp_t)___GFP_REPEAT) /* See above */ #define __GFP_NOFAIL ((__force gfp_t)___GFP_NOFAIL) /* See above */ #define __GFP_NORETRY ((__force gfp_t)___GFP_NORETRY) /* See above */ +#define __GFP_MEMALLOC ((__force gfp_t)___GFP_MEMALLOC)/* Use emergency reserves */ #define __GFP_COMP ((__force gfp_t)___GFP_COMP) /* Add compound page metadata */ #define __GFP_ZERO ((__force gfp_t)___GFP_ZERO) /* Return zeroed page on success */ #define __GFP_NOMEMALLOC ((__force gfp_t)___GFP_NOMEMALLOC) /* Don't use emergency reserves */ @@ -119,7 +121,7 @@ struct vm_area_struct; /* Control page allocator reclaim behavior */ #define GFP_RECLAIM_MASK (__GFP_WAIT|__GFP_HIGH|__GFP_IO|__GFP_FS|\ __GFP_NOWARN|__GFP_REPEAT|__GFP_NOFAIL|\ - __GFP_NORETRY|__GFP_NOMEMALLOC) + __GFP_NORETRY|__GFP_MEMALLOC|__GFP_NOMEMALLOC) /* Control slab gfp mask during early boot */ #define GFP_BOOT_MASK (__GFP_BITS_MASK & ~(__GFP_WAIT|__GFP_IO|__GFP_FS)) --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1944,7 +1944,9 @@ int gfp_to_alloc_flags(gfp_t gfp_mask) alloc_flags |= ALLOC_HARDER; if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) { - if (!in_irq() && (current->flags & PF_MEMALLOC)) + if (gfp_mask & __GFP_MEMALLOC) + alloc_flags |= ALLOC_NO_WATERMARKS; + else if (!in_irq() && (current->flags & PF_MEMALLOC)) alloc_flags |= ALLOC_NO_WATERMARKS; else if (!in_interrupt() && unlikely(test_thread_flag(TIF_MEMDIE)))