Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756018AbZFQQkj (ORCPT ); Wed, 17 Jun 2009 12:40:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753560AbZFQQkb (ORCPT ); Wed, 17 Jun 2009 12:40:31 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:55718 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751862AbZFQQkb (ORCPT ); Wed, 17 Jun 2009 12:40:31 -0400 Date: Wed, 17 Jun 2009 09:39:43 -0700 (PDT) From: Linus Torvalds X-X-Sender: torvalds@localhost.localdomain To: Ingo Molnar cc: Andrew Morton , Mel Gorman , Catalin Marinas , fengguang.wu@intel.com, Pekka Enberg , linux-kernel@vger.kernel.org Subject: Re: WARNING: at mm/page_alloc.c:1159 get_page_from_freelist+0x325/0x655() In-Reply-To: <20090617113120.GA5061@elte.hu> Message-ID: References: <200906162232.n5GMWRZe026963@imap1.linux-foundation.org> <20090616223649.719ea378.akpm@linux-foundation.org> <20090617111800.GA15261@elte.hu> <20090617113120.GA5061@elte.hu> User-Agent: Alpine 2.01 (LFD 1184 2008-12-16) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1207 Lines: 29 On Wed, 17 Jun 2009, Ingo Molnar wrote: > > a new warning started popping up today, in the new page allocator > code. The allocation came from kmemleak: We should probably print out the order. Right now it warns about any order but 0, and I think that's likely bogus. It's fine to allow small orders (I'd suggest 0-2), since we should always be able to get those, and small kmalloc's generally do want more than one page just to avoid crazy fragmentation issues. See, for example, the whole 'slab_break_gfp_order' logic in mm/slab.c: it very much expects to be able to use order-1 allocations for kmalloc() if there is enough memory (where "enough" is actually just 32MB). And slub seems to put some limit at PAGE_ALLOC_COSTLY_ORDER (3). So apart from anything else (ie this particular case is possibly fixable in kmemleak), I do think that we should likely allow at least order-1 and possible order-2 allocations with __GFP_NOFAIL too. Linus -- 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/