From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754279Ab1ATUNO (ORCPT ); Thu, 20 Jan 2011 15:13:14 -0500 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:42239 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752849Ab1ATUNK (ORCPT ); Thu, 20 Jan 2011 15:13:10 -0500 X-Authority-Analysis: v=1.1 cv=+c36koQ5Dcj/1qolKHjtkYAGXvrVJRRiKMp+84F5sLg= c=1 sm=0 a=ZNWVe3i0kLwA:10 a=kj9zAlcOel0A:10 a=OPBmh+XkhLl+Enan7BmTLg==:17 a=meVymXHHAAAA:8 a=20KFwNOVAAAA:8 a=VwQbUJbxAAAA:8 a=W0vUJOdyAAAA:8 a=I3wLOIAYSu1Gbog-1swA:9 a=MvmxXqKjbgUw6OH4QKwA:7 a=xchcOssQ5Ib8_Hq7MsCVFU_je0UA:4 a=CjuIK1q_8ugA:10 a=x8gzFH9gYPwA:10 a=jeBq3FmKZ4MA:10 a=jEp0ucaQiEUA:10 a=a-x9ayeGW0uss9RP:21 a=1ZYrpthnA9hQWNQq:21 a=OPBmh+XkhLl+Enan7BmTLg==:117 X-Cloudmark-Score: 0 X-Originating-IP: 67.242.120.143 Date: Thu, 20 Jan 2011 15:13:06 -0500 From: Steven Rostedt To: Andrea Arcangeli Cc: Borislav Petkov , werner , linux-kernel@vger.kernel.org, linux-mm , Andrew Morton Subject: Re: 2.6.38-rc1 problems with khugepaged Message-ID: <20110120201306.GA2025@home.goodmis.org> References: <20110119155954.GA2272@kryptos.osrc.amd.com> <20110119222150.GP9506@random.random> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110119222150.GP9506@random.random> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 19, 2011 at 11:21:50PM +0100, Andrea Arcangeli wrote: > Hello Werner, > > this should fix your oops, it's untested still so let me know if you > test it. I tested this with ktest.pl on the config that was breaking for me. I ran the test 20 times and it succeeded for all 20 tests. Tested-by: Steven Rostedt -- Steve > > It's a noop for x86_64 and it only affected x86 32bit with highpte enabled. > > ==== > Subject: khugepaged: fix pte_unmap for highpte x86_32 > > From: Andrea Arcangeli > > __collapse_huge_page_copy is still dereferencing the pte passed as parameter so > we must pte_unmap after __collapse_huge_page_copy returns, not before. > > Signed-off-by: Andrea Arcangeli > --- > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index 004c9c2..c4f634b 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -1837,9 +1837,9 @@ static void collapse_huge_page(struct mm_struct *mm, > spin_lock(ptl); > isolated = __collapse_huge_page_isolate(vma, address, pte); > spin_unlock(ptl); > - pte_unmap(pte); > > if (unlikely(!isolated)) { > + pte_unmap(pte); > spin_lock(&mm->page_table_lock); > BUG_ON(!pmd_none(*pmd)); > set_pmd_at(mm, address, pmd, _pmd); > @@ -1856,6 +1856,7 @@ static void collapse_huge_page(struct mm_struct *mm, > anon_vma_unlock(vma->anon_vma); > > __collapse_huge_page_copy(pte, new_page, vma, address, ptl); > + pte_unmap(pte); > __SetPageUptodate(new_page); > pgtable = pmd_pgtable(_pmd); > VM_BUG_ON(page_count(pgtable) != 1); > > > -- > 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/