Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755751AbbHLKsd (ORCPT ); Wed, 12 Aug 2015 06:48:33 -0400 Received: from outbound-smtp04.blacknight.com ([81.17.249.35]:49223 "EHLO outbound-smtp04.blacknight.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933329AbbHLKpi (ORCPT ); Wed, 12 Aug 2015 06:45:38 -0400 From: Mel Gorman To: Linux-MM Cc: Johannes Weiner , Rik van Riel , Vlastimil Babka , David Rientjes , Joonsoo Kim , Michal Hocko , LKML , Mel Gorman Subject: [PATCH 05/10] mm, page_alloc: Use masks and shifts when converting GFP flags to migrate types Date: Wed, 12 Aug 2015 11:45:30 +0100 Message-Id: <1439376335-17895-6-git-send-email-mgorman@techsingularity.net> X-Mailer: git-send-email 2.4.6 In-Reply-To: <1439376335-17895-1-git-send-email-mgorman@techsingularity.net> References: <1439376335-17895-1-git-send-email-mgorman@techsingularity.net> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2988 Lines: 83 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..43246850a85f 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 8b86ec5df968..79a0d033a2f3 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 from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/