Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756653AbYC1SRS (ORCPT ); Fri, 28 Mar 2008 14:17:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754391AbYC1SRI (ORCPT ); Fri, 28 Mar 2008 14:17:08 -0400 Received: from wf-out-1314.google.com ([209.85.200.174]:47101 "EHLO wf-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754252AbYC1SRG (ORCPT ); Fri, 28 Mar 2008 14:17:06 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=message-id:date:from:sender:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references:x-google-sender-auth; b=bh2TwAD6ttO8lEDY69JwVtqwwLPy5q+stHD4kVhN4bLfIR9YnNiYtgXapCKXaTFULW4fdYah/F7fkz+JPihXRP3pYePL10OkcSENbQrt+Ig2Gf/S0lsvUchgidxtSgnAxf1d6l6cqtxEuh4DKblmEz8b7WDALhxvMRHXPl15KhM= Message-ID: <84144f020803281108o178bf62cp48dcd4f43ec59b74@mail.gmail.com> Date: Fri, 28 Mar 2008 20:08:33 +0200 From: "Pekka Enberg" To: "Linus Torvalds" Subject: Re: 2.6.25-rc7-git2: Reported regressions from 2.6.24 Cc: "Christoph Lameter" , "Rafael J. Wysocki" , "Pawel Staszewski" , LKML , "Adrian Bunk" , "Andrew Morton" , "Natalie Protasevich" In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <200803272353.51901.rjw@sisk.pl> <84144f020803281015s60370d9dpec0913c33004b6c2@mail.gmail.com> X-Google-Sender-Auth: a4e6d5971e532799 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1760 Lines: 39 Hi Linus, On Fri, 28 Mar 2008, Pekka Enberg wrote: > > We clear GFP_ZERO in new_slab() so the normal kmalloc()/kzalloc() path > > should be fine but don't do it for kmalloc_large() nor > > kmalloc_large_node(). Is that the bug here? On Fri, Mar 28, 2008 at 7:27 PM, Linus Torvalds wrote: > Dammit, NO. > > The bug was that the commit I made (which was correct and robust) was then > partially reverted by Christoph for no good reason. At that point, > kmalloc_large() didn't even exist, so at that point the change was > "technically correct" (since the only user of gfpflags really did end up > clearing it somewhere deep in its callchain). I was not implying that we should clear GFP_ZERO in kmalloc_large() but that we can hit the page allocator with GFP_ZERO via kmalloc() and kzalloc() for size > PAGE_SIZE allocations. And asking Christoph if that's the bug we're seeing here. On Fri, Mar 28, 2008 at 7:27 PM, Linus Torvalds wrote: > So the *last* thing we want to do is to clear GFP_ZERO in multiple subtle > places based on new random code being added. We want to clear it at the > top level, so that no other code never ever even has to _think_ about it! We are clearing it in one place, just before calling alloc_pages. [Yes, it's hard to spot, it's in new_slab() where we call allocate_slab().] I'm okay with moving it to top level but I don't see how that fixes any of the bugs mentioned here. Pekka -- 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/