Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755046Ab0HQIAE (ORCPT ); Tue, 17 Aug 2010 04:00:04 -0400 Received: from hera.kernel.org ([140.211.167.34]:33632 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751955Ab0HQIAD (ORCPT ); Tue, 17 Aug 2010 04:00:03 -0400 Message-ID: <4C6A408C.6040203@kernel.org> Date: Tue, 17 Aug 2010 09:55:56 +0200 From: Tejun Heo User-Agent: Mozilla/5.0 (X11; U; Linux i686 (x86_64); en-US; rv:1.9.2.8) Gecko/20100802 Thunderbird/3.1.2 MIME-Version: 1.0 To: David Rientjes CC: Christoph Lameter , Pekka Enberg , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Nick Piggin Subject: Re: [S+Q3 00/23] SLUB: The Unified slab allocator (V3) References: <20100804024514.139976032@linux.com> In-Reply-To: X-Enigmail-Version: 1.1.1 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Tue, 17 Aug 2010 07:59:02 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1475 Lines: 32 Hello, On 08/17/2010 06:56 AM, David Rientjes wrote: > I'm adding Tejun Heo to the cc because of another thing that may be > problematic: alloc_percpu() allocates GFP_KERNEL memory, so when we try to > allocate kmem_cache_cpu for a DMA cache we may be returning memory from a > node that doesn't include lowmem so there will be no affinity between the > struct and the slab. I'm wondering if it would be better for the percpu > allocator to be extended for kzalloc_node(), or vmalloc_node(), when > allocating memory after the slab layer is up. Hmmm... do you mean adding @gfp_mask to percpu allocation function? I've been thinking about adding it for atomic allocations (Christoph, do you still want it?). I've been sort of against it because I primarily don't really like atomic allocations (it often just pushes error handling complexities elsewhere where it becomes more complex) and it would also require making vmalloc code do atomic allocations. Most of percpu use cases seem pretty happy with GFP_KERNEL allocation, so I'm still quite reluctant to change that. We can add a semi internal interface w/ @gfp_mask but w/o GFP_ATOMIC support, which is a bit ugly. How important would this be? Thanks. -- tejun -- 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/