From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758494AbYJVR6n (ORCPT ); Wed, 22 Oct 2008 13:58:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753018AbYJVR6d (ORCPT ); Wed, 22 Oct 2008 13:58:33 -0400 Received: from nf-out-0910.google.com ([64.233.182.187]:44260 "EHLO nf-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751631AbYJVR6c (ORCPT ); Wed, 22 Oct 2008 13:58:32 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=LLFdByfSM7ZTNHPs/5LCeBfncoFtsuaTB4UUjeDHrXA6cy3Uhor6YxAlZxHDLc+ncD HpVfuvDx0Of+LwSUsr5tdIeHZYfGzkGY7MvYRqmcV3dqwn/LxTUuiCC/bNbglFf/9Vd0 TwxL2ttag3UFrk/poRHz5uON09tWbOTXQ0YGU= Date: Wed, 22 Oct 2008 21:58:27 +0400 From: Cyrill Gorcunov To: Pekka Enberg Cc: Christoph Lameter , LKML Subject: Re: [RFC] SLUB - define OO_ macro instead of hardcoded numbers Message-ID: <20081022175827.GL9639@localhost> References: <20081022161836.GG9639@localhost> <20081022163530.GH9639@localhost> <20081022165354.GI9639@localhost> <20081022172103.GJ9639@localhost> <48FF6800.20705@cs.helsinki.fi> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <48FF6800.20705@cs.helsinki.fi> User-Agent: Mutt/1.5.17+20080114 (2008-01-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [Pekka Enberg - Wed, Oct 22, 2008 at 08:50:56PM +0300] > Christoph Lameter wrote: >> On Wed, 22 Oct 2008, Cyrill Gorcunov wrote: >> >>> Christoph how about this one? >> >> Ok. Looks a bit better but we still have two maxes here >> >> s->max which refers to the maximum number of objects per slab page for >> a specific slab cache (depends on the runtime configuration). >> OO_MAX_OBJS refers to the maximum number of objects per slab page that >> any slab cache can be configured for which is a compile time limit. >> >> Maybe this is okay, Pekka? > > Maybe call the page->objects maximum MAX_OBJS_PER_PAGE as it's not > strictly related to the other OO code? > > Pekka > Something like that? - Cyrill - --- mm/slub.c | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-) Index: linux-2.6.git/mm/slub.c =================================================================== --- linux-2.6.git.orig/mm/slub.c 2008-10-22 21:11:26.000000000 +0400 +++ linux-2.6.git/mm/slub.c 2008-10-22 21:57:11.000000000 +0400 @@ -153,6 +153,10 @@ #define ARCH_SLAB_MINALIGN __alignof__(unsigned long long) #endif +#define OO_SHIFT 16 +#define OO_MASK ((1 << OO_SHIFT) - 1) +#define MAX_OBJS_PER_PAGE 65535 /* see struct page.objects */ + /* Internal SLUB flags */ #define __OBJECT_POISON 0x80000000 /* Poison object */ #define __SYSFS_ADD_DEFERRED 0x40000000 /* Not yet visible via sysfs */ @@ -290,7 +294,7 @@ static inline struct kmem_cache_order_ob unsigned long size) { struct kmem_cache_order_objects x = { - (order << 16) + (PAGE_SIZE << order) / size + (order << OO_SHIFT) + (PAGE_SIZE << order) / size }; return x; @@ -298,12 +302,12 @@ static inline struct kmem_cache_order_ob static inline int oo_order(struct kmem_cache_order_objects x) { - return x.x >> 16; + return x.x >> OO_SHIFT; } static inline int oo_objects(struct kmem_cache_order_objects x) { - return x.x & ((1 << 16) - 1); + return x.x & OO_MASK; } #ifdef CONFIG_SLUB_DEBUG @@ -764,8 +768,8 @@ static int on_freelist(struct kmem_cache } max_objects = (PAGE_SIZE << compound_order(page)) / s->size; - if (max_objects > 65535) - max_objects = 65535; + if (max_objects > MAX_OBJS_PER_PAGE) + max_objects = MAX_OBJS_PER_PAGE; if (page->objects != max_objects) { slab_err(s, page, "Wrong number of objects. Found %d but " @@ -1819,8 +1823,8 @@ static inline int slab_order(int size, i int rem; int min_order = slub_min_order; - if ((PAGE_SIZE << min_order) / size > 65535) - return get_order(size * 65535) - 1; + if ((PAGE_SIZE << min_order) / size > MAX_OBJS_PER_PAGE) + return get_order(size * MAX_OBJS_PER_PAGE) - 1; for (order = max(min_order, fls(min_objects * size - 1) - PAGE_SHIFT);