From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx161.postini.com [74.125.245.161]) by kanga.kvack.org (Postfix) with SMTP id ADDA26B0006 for ; Fri, 18 Jan 2013 10:29:54 -0500 (EST) Message-ID: <1358522992.7383.13.camel@gandalf.local.home> Subject: Re: [RFC][PATCH v2] slub: Keep page and object in sync in slab_alloc_node() From: Steven Rostedt Date: Fri, 18 Jan 2013 10:29:52 -0500 In-Reply-To: <20130118044242.GA18665@lge.com> References: <1358446258.23211.32.camel@gandalf.local.home> <1358447864.23211.34.camel@gandalf.local.home> <0000013c4a69a2cf-1a19a6f6-e6a3-4f06-99a4-10fdd4b9aca2-000000@email.amazonses.com> <1358458996.23211.46.camel@gandalf.local.home> <0000013c4a7e7fbf-c51fd42a-2455-4fec-bb37-915035956f05-000000@email.amazonses.com> <1358462763.23211.57.camel@gandalf.local.home> <1358464245.23211.62.camel@gandalf.local.home> <1358464837.23211.66.camel@gandalf.local.home> <1358468598.23211.67.camel@gandalf.local.home> <1358468924.23211.69.camel@gandalf.local.home> <20130118044242.GA18665@lge.com> Content-Type: text/plain; charset="ISO-8859-15" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Joonsoo Kim Cc: Christoph Lameter , LKML , linux-mm , Andrew Morton , Pekka Enberg , Matt Mackall , Thomas Gleixner , RT , Clark Williams , John Kacur , "Luis Claudio R. Goncalves" On Fri, 2013-01-18 at 13:42 +0900, Joonsoo Kim wrote: > diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h > index 9db4825..b54dffa 100644 > --- a/include/linux/slub_def.h > +++ b/include/linux/slub_def.h > @@ -46,6 +46,9 @@ enum stat_item { > struct kmem_cache_cpu { > void **freelist; /* Pointer to next available object */ > unsigned long tid; /* Globally unique transaction id */ > +#ifdef CONFIG_NUMA > + int node; Note, you put an int between a long and a pointer, which will waste 4 bytes on 64bit machines. > +#endif > struct page *page; /* The slab from which we are allocating */ > struct page *partial; /* Partially allocated frozen slabs */ > #ifdef CONFIG_SLUB_STATS > @@ -2038,10 +2049,10 @@ static void flush_all(struct kmem_cache *s) > * Check if the objects in a per cpu structure fit numa > * locality expectations. > */ > -static inline int node_match(struct page *page, int node) > +static inline int node_match(struct kmem_cache_cpu *c, int node) > { > #ifdef CONFIG_NUMA > - if (node != NUMA_NO_NODE && page_to_nid(page) != node) > + if (node != NUMA_NO_NODE && c->node != node) We still have the issue of cpu fetching c->node before c->tid and c->freelist. I still believe the only solution is to prevent the task from migrating via a preempt disable. -- Steve -- 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