From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-we0-f172.google.com (mail-we0-f172.google.com [74.125.82.172]) by kanga.kvack.org (Postfix) with ESMTP id D2AC16B0031 for ; Sat, 14 Jun 2014 08:05:25 -0400 (EDT) Received: by mail-we0-f172.google.com with SMTP id u57so3887215wes.31 for ; Sat, 14 Jun 2014 05:05:25 -0700 (PDT) Received: from mail-we0-x22b.google.com (mail-we0-x22b.google.com [2a00:1450:400c:c03::22b]) by mx.google.com with ESMTPS id j15si10748253wjn.21.2014.06.14.05.05.23 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Sat, 14 Jun 2014 05:05:24 -0700 (PDT) Received: by mail-we0-f171.google.com with SMTP id q58so3879188wes.16 for ; Sat, 14 Jun 2014 05:05:23 -0700 (PDT) Subject: Re: kmemleak: Unable to handle kernel paging request Mime-Version: 1.0 (Mac OS X Mail 7.3 \(1878.2\)) Content-Type: text/plain; charset=windows-1252 From: Catalin Marinas In-Reply-To: <1402695853.20360.17.camel@pasglop> Date: Sat, 14 Jun 2014 13:05:18 +0100 Content-Transfer-Encoding: quoted-printable Message-Id: References: <20140611173851.GA5556@MacBook-Pro.local> <20140612143916.GB8970@arm.com> <20140613085640.GA21018@arm.com> <1402695853.20360.17.camel@pasglop> Sender: owner-linux-mm@kvack.org List-ID: To: Benjamin Herrenschmidt Cc: Denis Kirjanov , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , Naoya Horiguchi , "linuxppc-dev@lists.ozlabs.org" , Paul Mackerras On 13 Jun 2014, at 22:44, Benjamin Herrenschmidt = wrote: > On Fri, 2014-06-13 at 09:56 +0100, Catalin Marinas wrote: >=20 >> OK, so that's the DART table allocated via alloc_dart_table(). Is >> dart_tablebase removed from the kernel linear mapping after = allocation? >=20 > Yes. >=20 >> If that's the case, we need to tell kmemleak to ignore this block = (see >> patch below, untested). But I still can't explain how commit >> d4c54919ed863020 causes this issue. >>=20 >> (also cc'ing the powerpc list and maintainers) >=20 > We remove the DART from the linear mapping because it has to be mapped > non-cachable and having it in the linear mapping would cause cache > paradoxes. We also can't just change the caching attributes in the > linear mapping because we use 16M pages for it and 970 CPUs don't > support cache-inhibited 16M pages :-( And due to the MMU segmentation > model, we also can't mix & match page sizes in that area. >=20 > So we just unmap it, and ioremap it elsewhere. OK, thanks for the explanation. So the kmemleak annotation makes sense. Would you please take the I patch earlier (I guess with Denis=92 tested- by). I can send it separately if more convenient. Thanks, Catalin= -- 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