From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 17 Jan 2006 13:22:14 -0800 From: Andrew Morton Subject: Re: [PATCH] zone gfp_flags generate from ZONE_ constants Message-Id: <20060117132214.2db664e2.akpm@osdl.org> In-Reply-To: <20060117155227.GA16176@shadowen.org> References: <20060117155227.GA16176@shadowen.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Andy Whitcroft Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: Andy Whitcroft wrote: > > +/* > + * Generate the zone modifier bit. Zone ZONE_DEFAULT doesn't require a bit > + * as the absence of all zone modifiers implies this zone. Renormalise the > + * zone number such that ZONE_DEFAULT is at the bottom and discard it. > + * These must fit within the bitmask GFP_ZONEMASK defined in linux/mmzone.h. > + */ > +#define __ZONE_BIT(x) (((x) ^ ZONE_DEFAULT) - 1) > +#define ZONE_MODIFIER(x) ((__force gfp_t)(((x) == ZONE_DEFAULT)? (0) : \ > + 1UL << __ZONE_BIT(x))) > + > +#define __GFP_DMA ZONE_MODIFIER(ZONE_DMA) > +#define __GFP_HIGHMEM ZONE_MODIFIER(ZONE_HIGHMEM) > #ifdef CONFIG_DMA_IS_DMA32 > -#define __GFP_DMA32 ((__force gfp_t)0x01) /* ZONE_DMA is ZONE_DMA32 */ > +#define __GFP_DMA32 ZONE_MODIFIER(ZONE_DMA) /* ZONE_DMA is ZONE_DMA32 */ > #elif BITS_PER_LONG < 64 > -#define __GFP_DMA32 ((__force gfp_t)0x00) /* ZONE_NORMAL is ZONE_DMA32 */ > +#define __GFP_DMA32 ZONE_MODIFIER(ZONE_NORMAL) /* ZONE_NORMAL is ZONE_DMA32 */ > #else > -#define __GFP_DMA32 ((__force gfp_t)0x04) /* Has own ZONE_DMA32 */ > +#define __GFP_DMA32 ZONE_MODIFIER(ZONE_DMA32) /* Has own ZONE_DMA32 */ > #endif eek. We often look at the hex value of gfp flags in debug output to work out what sort of allocation is being attempted. I guess we could print out the values of these things at boot time.. -- 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