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 | 3 ++- mm/page_alloc.c | 4 +++- 2 files changed, 5 insertions(+), 2 deletions(-) --- a/include/linux/gfp.h +++ b/include/linux/gfp.h @@ -47,6 +47,7 @@ struct vm_area_struct; #define __GFP_REPEAT ((__force gfp_t)0x400u) /* See above */ #define __GFP_NOFAIL ((__force gfp_t)0x800u) /* See above */ #define __GFP_NORETRY ((__force gfp_t)0x1000u)/* See above */ +#define __GFP_MEMALLOC ((__force gfp_t)0x2000u)/* Use emergency reserves */ #define __GFP_COMP ((__force gfp_t)0x4000u)/* Add compound page metadata */ #define __GFP_ZERO ((__force gfp_t)0x8000u)/* Return zeroed page on success */ #define __GFP_NOMEMALLOC ((__force gfp_t)0x10000u) /* Don't use emergency reserves */ @@ -98,7 +99,7 @@ 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 @@ -1787,7 +1787,9 @@ int gfp_to_alloc_flags(gfp_t gfp_mask) alloc_flags |= ALLOC_HARDER; if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) { - if (!in_irq() && (p->flags & PF_MEMALLOC)) + if (gfp_mask & __GFP_MEMALLOC) + alloc_flags |= ALLOC_NO_WATERMARKS; + else if (!in_irq() && (p->flags & PF_MEMALLOC)) alloc_flags |= ALLOC_NO_WATERMARKS; else if (!in_interrupt() && unlikely(test_thread_flag(TIF_MEMDIE)))