From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f53.google.com (mail-pa0-f53.google.com [209.85.220.53]) by kanga.kvack.org (Postfix) with ESMTP id 972466B0036 for ; Mon, 13 Jan 2014 17:17:51 -0500 (EST) Received: by mail-pa0-f53.google.com with SMTP id lj1so413154pab.40 for ; Mon, 13 Jan 2014 14:17:51 -0800 (PST) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by mx.google.com with ESMTP id nu5si16882625pbc.58.2014.01.13.14.17.49 for ; Mon, 13 Jan 2014 14:17:50 -0800 (PST) Date: Mon, 13 Jan 2014 14:17:48 -0800 From: Andrew Morton Subject: Re: [PATCH] powerpc: thp: Fix crash on mremap Message-Id: <20140113141748.0b851e1573e41bf26de7c0ae@linux-foundation.org> In-Reply-To: <20140102021951.GA26369@node.dhcp.inet.fi> References: <1388570027-22933-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <1388572145.4373.41.camel@pasglop> <20140102021951.GA26369@node.dhcp.inet.fi> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: "Kirill A. Shutemov" Cc: Benjamin Herrenschmidt , "Aneesh Kumar K.V" , paulus@samba.org, aarcange@redhat.com, kirill.shutemov@linux.intel.com, linuxppc-dev@lists.ozlabs.org, linux-mm@kvack.org On Thu, 2 Jan 2014 04:19:51 +0200 "Kirill A. Shutemov" wrote: > On Wed, Jan 01, 2014 at 09:29:05PM +1100, Benjamin Herrenschmidt wrote: > > On Wed, 2014-01-01 at 15:23 +0530, Aneesh Kumar K.V wrote: > > > From: "Aneesh Kumar K.V" > > > > > > This patch fix the below crash > > > > > > NIP [c00000000004cee4] .__hash_page_thp+0x2a4/0x440 > > > LR [c0000000000439ac] .hash_page+0x18c/0x5e0 > > > ... > > > Call Trace: > > > [c000000736103c40] [00001ffffb000000] 0x1ffffb000000(unreliable) > > > [437908.479693] [c000000736103d50] [c0000000000439ac] .hash_page+0x18c/0x5e0 > > > [437908.479699] [c000000736103e30] [c00000000000924c] .do_hash_page+0x4c/0x58 > > > > > > On ppc64 we use the pgtable for storing the hpte slot information and > > > store address to the pgtable at a constant offset (PTRS_PER_PMD) from > > > pmd. On mremap, when we switch the pmd, we need to withdraw and deposit > > > the pgtable again, so that we find the pgtable at PTRS_PER_PMD offset > > > from new pmd. > > > > > > We also want to move the withdraw and deposit before the set_pmd so > > > that, when page fault find the pmd as trans huge we can be sure that > > > pgtable can be located at the offset. > > > Did this get fixed? -- 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