Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754065Ab3JBP5Q (ORCPT ); Wed, 2 Oct 2013 11:57:16 -0400 Received: from a9-70.smtp-out.amazonses.com ([54.240.9.70]:44364 "EHLO a9-70.smtp-out.amazonses.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753339Ab3JBP5O (ORCPT ); Wed, 2 Oct 2013 11:57:14 -0400 Date: Wed, 2 Oct 2013 15:57:12 +0000 From: Christoph Lameter X-X-Sender: cl@gentwo.org To: "Bird, Tim" cc: Frank Rowand , Pekka Enberg , Matt Mackall , "linux-mm@kvack.org" , Linux Kernel list , Catalin Marinas , "Bobniev, Roman" , =?ISO-8859-15?Q?=22Andersson=2C_Bj=F6rn=22?= Subject: RE: [PATCH] slub: Proper kmemleak tracking if CONFIG_SLUB_DEBUG disabled In-Reply-To: Message-ID: <0000014179e31953-a05dd7d1-d0f8-474f-810a-809cd8a724f8-000000@email.amazonses.com> References: <5245ECC3.8070200@gmail.com>,<00000141799dd4b3-f6df96c0-1003-427d-9bd8-f6455622f4ea-000000@email.amazonses.com> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-SES-Outgoing: 2013.10.02-54.240.9.70 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1546 Lines: 33 On Wed, 2 Oct 2013, Bird, Tim wrote: > The problem child is actually the unconditional call to kmemleak_alloc() > in kmalloc_large_node() (in slub.c). The problem comes because that call > is unconditional on CONFIG_SLUB_DEBUG but the kmemleak > calls in the hook routines are conditional on CONFIG_SLUB_DEBUG. > So if you have CONFIG_SLUB_DEBUG=n but CONFIG_DEBUG_KMEMLEAK=y, > you get the false reports. Right. You need to put the #ifdef CONFIG_SLUB_DEBUG around the hooks that need it in the function itself instead of disabling the whole function if CONFIG_SLUB_DEUBG is not set. > Now, there are kmemleak calls in kmalloc_large_node() and kfree() that don't > follow the "hook" pattern. Should these be moved to 'hook' routines, to keep > all the checks in the hooks? That would be great. > Personally, I like the idea of keeping bookeeping/tracing/debug stuff in hook > routines. I also like de-coupling CONFIG_SLUB_DEBUG and CONFIG_DEBUG_KMEMLEAK, > but maybe others have a different opinon. Unless someone speaks up, we'll > move the the currently in-function kmemleak calls into hooks, and all of the > kmemleak stuff out from under CONFIG_SLUB_DEBUG. > We'll have to see if the ifdefs get a little messy. Decouple of you want. CONFIG_SLUB_DEBUG may duplicate what you already do. -- 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/