From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757378AbYJVSFA (ORCPT ); Wed, 22 Oct 2008 14:05:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752894AbYJVSEu (ORCPT ); Wed, 22 Oct 2008 14:04:50 -0400 Received: from courier.cs.helsinki.fi ([128.214.9.1]:47464 "EHLO mail.cs.helsinki.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752738AbYJVSEt (ORCPT ); Wed, 22 Oct 2008 14:04:49 -0400 Message-ID: <48FF6A5D.5060905@cs.helsinki.fi> Date: Wed, 22 Oct 2008 21:01:01 +0300 From: Pekka Enberg User-Agent: Thunderbird 2.0.0.17 (Macintosh/20080914) MIME-Version: 1.0 To: Cyrill Gorcunov CC: Christoph Lameter , LKML Subject: Re: [RFC] SLUB - define OO_ macro instead of hardcoded numbers References: <20081022161836.GG9639@localhost> <20081022163530.GH9639@localhost> <20081022165354.GI9639@localhost> <20081022172103.GJ9639@localhost> <48FF6800.20705@cs.helsinki.fi> <20081022175827.GL9639@localhost> In-Reply-To: <20081022175827.GL9639@localhost> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Cyrill Gorcunov wrote: > 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); Looks good to me. If Christoph ACKs this, please send me a proper patch with your sign-off and I'll merge it to slab.git. Pekka