From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f179.google.com (mail-wi0-f179.google.com [209.85.212.179]) by kanga.kvack.org (Postfix) with ESMTP id 4BE946B0259 for ; Mon, 24 Aug 2015 08:10:06 -0400 (EDT) Received: by widdq5 with SMTP id dq5so48116602wid.1 for ; Mon, 24 Aug 2015 05:10:05 -0700 (PDT) Received: from outbound-smtp01.blacknight.com (outbound-smtp01.blacknight.com. [81.17.249.7]) by mx.google.com with ESMTPS id z17si31651962wjr.115.2015.08.24.05.09.53 for (version=TLS1 cipher=RC4-SHA bits=128/128); Mon, 24 Aug 2015 05:09:54 -0700 (PDT) Received: from mail.blacknight.com (pemlinmail02.blacknight.ie [81.17.254.11]) by outbound-smtp01.blacknight.com (Postfix) with ESMTPS id 9A3C799115 for ; Mon, 24 Aug 2015 12:09:53 +0000 (UTC) From: Mel Gorman Subject: [PATCH 06/12] mm, page_alloc: Use masks and shifts when converting GFP flags to migrate types Date: Mon, 24 Aug 2015 13:09:45 +0100 Message-Id: <1440418191-10894-7-git-send-email-mgorman@techsingularity.net> In-Reply-To: <1440418191-10894-1-git-send-email-mgorman@techsingularity.net> References: <1440418191-10894-1-git-send-email-mgorman@techsingularity.net> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: Johannes Weiner , Rik van Riel , Vlastimil Babka , David Rientjes , Joonsoo Kim , Michal Hocko , Linux-MM , LKML , Mel Gorman This patch redefines which GFP bits are used for specifying mobility and the order of the migrate types. Once redefined it's possible to convert GFP flags to a migrate type with a simple mask and shift. The only downside is that readers of OOM kill messages and allocation failures may have been used to the existing values but scripts/gfp-translate will help. Signed-off-by: Mel Gorman --- include/linux/gfp.h | 12 +++++++----- include/linux/mmzone.h | 2 +- 2 files changed, 8 insertions(+), 6 deletions(-) diff --git a/include/linux/gfp.h b/include/linux/gfp.h index ad35f300b9a4..a10347ca5053 100644 --- a/include/linux/gfp.h +++ b/include/linux/gfp.h @@ -14,7 +14,7 @@ struct vm_area_struct; #define ___GFP_HIGHMEM 0x02u #define ___GFP_DMA32 0x04u #define ___GFP_MOVABLE 0x08u -#define ___GFP_WAIT 0x10u +#define ___GFP_RECLAIMABLE 0x10u #define ___GFP_HIGH 0x20u #define ___GFP_IO 0x40u #define ___GFP_FS 0x80u @@ -29,7 +29,7 @@ struct vm_area_struct; #define ___GFP_NOMEMALLOC 0x10000u #define ___GFP_HARDWALL 0x20000u #define ___GFP_THISNODE 0x40000u -#define ___GFP_RECLAIMABLE 0x80000u +#define ___GFP_WAIT 0x80000u #define ___GFP_NOACCOUNT 0x100000u #define ___GFP_NOTRACK 0x200000u #define ___GFP_NO_KSWAPD 0x400000u @@ -123,6 +123,7 @@ struct vm_area_struct; /* This mask makes up all the page movable related flags */ #define GFP_MOVABLE_MASK (__GFP_RECLAIMABLE|__GFP_MOVABLE) +#define GFP_MOVABLE_SHIFT 3 /* Control page allocator reclaim behavior */ #define GFP_RECLAIM_MASK (__GFP_WAIT|__GFP_HIGH|__GFP_IO|__GFP_FS|\ @@ -149,14 +150,15 @@ struct vm_area_struct; /* Convert GFP flags to their corresponding migrate type */ static inline int gfpflags_to_migratetype(const gfp_t gfp_flags) { - WARN_ON((gfp_flags & GFP_MOVABLE_MASK) == GFP_MOVABLE_MASK); + VM_WARN_ON((gfp_flags & GFP_MOVABLE_MASK) == GFP_MOVABLE_MASK); + BUILD_BUG_ON((1UL << GFP_MOVABLE_SHIFT) != ___GFP_MOVABLE); + BUILD_BUG_ON((___GFP_MOVABLE >> GFP_MOVABLE_SHIFT) != MIGRATE_MOVABLE); if (unlikely(page_group_by_mobility_disabled)) return MIGRATE_UNMOVABLE; /* Group based on mobility */ - return (((gfp_flags & __GFP_MOVABLE) != 0) << 1) | - ((gfp_flags & __GFP_RECLAIMABLE) != 0); + return (gfp_flags & GFP_MOVABLE_MASK) >> GFP_MOVABLE_SHIFT; } #ifdef CONFIG_HIGHMEM diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 99cf4209cd45..fc0457d005f8 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -37,8 +37,8 @@ enum { MIGRATE_UNMOVABLE, - MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, + MIGRATE_RECLAIMABLE, MIGRATE_PCPTYPES, /* the number of types on the pcp lists */ MIGRATE_RESERVE = MIGRATE_PCPTYPES, #ifdef CONFIG_CMA -- 2.4.6 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org