From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-2993705-1519909843-2-6088137735392559528 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, ME_NOAUTH 0.01, RCVD_IN_DNSWL_HI -5, T_RP_MATCHES_RCVD -0.01, LANGUAGES en, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='CN', FromHeader='org', MailFrom='org' X-Spam-charsets: plain='us-ascii' X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: stable-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=arctest; t=1519909842; b=d0X3uLETDjNg6JlvbZViglu9Z46EpGSgjSVonGsqzZzrbbo pb991bjELjJnFmTcigYZoRWCHpBIvZO58y4eQeLzzzadeiq1Rv7brxWrZTKtE+qd LPLLL7D1Aih7eHCARppBQCgQlD4WPKkDm86iwlvHPU3CYiFinhbFsc7YjSYyMP8w DWXTLCITpYlc3/O4CRtEvZhlzXhT6+4GzImi7MZkTLmy+SgxRGkKCkbNRI1bB9mw 2ds241oKdmbn1vpTWCvNe0JzcUl9BC8RoNxnQGxhJXZA5Vm9v1r4lyCAtdLFayk+ MnjpmAvndF5BhLdgratQb58aEmodCP/qTf2jmHw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=date:from:to:cc:subject:message-id :references:mime-version:content-type:in-reply-to:sender :list-id; s=arctest; t=1519909842; bh=XQCubfdYrK/ST6FDmyzUsJk77u K9egw4DaIoUhSLWIQ=; b=uBap19v6osTzSwJl0ihF4FnUbVTbpxPSRWQtYpesME 7tuihMODLI7wqeh5fp4MoNuLEEotekdZMlV8pSYgTjhVMeqDwijjMNTE+Kp7gNH4 khZoiIjdIZE2c7P7F9ZpEo7TWGw3Cf9xRpWOVcROESt4YIjN2pM7JdKQLRrooiws oAHtvNWKeWrSVUseihc64Vh/TXI8pnH8k552LYnC8svXes5j6/jpeT7DYSD+Q4lS KkJZx1oNySVOjdB03zPQ6CFJ3qWlSCd2+o74cf5x/ZR2KFCQtSJlf1EB+1swgPJO msvK231jTWSwXnei2EvmOgor3fisuRli18F1EBH4aVdA== ARC-Authentication-Results: i=1; mx3.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=kernel.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=orgdomain_pass; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=kernel.org header.result=pass header_is_org_domain=yes Authentication-Results: mx3.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=kernel.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=orgdomain_pass; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=kernel.org header.result=pass header_is_org_domain=yes Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030519AbeCANKh (ORCPT ); Thu, 1 Mar 2018 08:10:37 -0500 Received: from mx2.suse.de ([195.135.220.15]:56265 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030517AbeCANKg (ORCPT ); Thu, 1 Mar 2018 08:10:36 -0500 Date: Thu, 1 Mar 2018 14:10:33 +0100 From: Michal Hocko To: Daniel Vacek Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andrew Morton , Vlastimil Babka , Mel Gorman , Pavel Tatashin , Paul Burton , stable@vger.kernel.org Subject: Re: [PATCH] mm/page_alloc: fix memmap_init_zone pageblock alignment Message-ID: <20180301131033.GH15057@dhcp22.suse.cz> References: <1519908465-12328-1-git-send-email-neelx@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1519908465-12328-1-git-send-email-neelx@redhat.com> User-Agent: Mutt/1.9.3 (2018-01-21) Sender: stable-owner@vger.kernel.org X-Mailing-List: stable@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On Thu 01-03-18 13:47:45, Daniel Vacek wrote: > In move_freepages() a BUG_ON() can be triggered on uninitialized page structures > due to pageblock alignment. Aligning the skipped pfns in memmap_init_zone() the > same way as in move_freepages_block() simply fixes those crashes. This changelog doesn't describe how the fix works. Why doesn't memblock_next_valid_pfn return the first valid pfn as one would expect? It would be also good put the panic info in the changelog. > Fixes: b92df1de5d28 ("[mm] page_alloc: skip over regions of invalid pfns where possible") > Signed-off-by: Daniel Vacek > Cc: stable@vger.kernel.org > --- > mm/page_alloc.c | 9 +++++++-- > 1 file changed, 7 insertions(+), 2 deletions(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index cb416723538f..9edee36e6a74 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -5359,9 +5359,14 @@ void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, > /* > * Skip to the pfn preceding the next valid one (or > * end_pfn), such that we hit a valid pfn (or end_pfn) > - * on our next iteration of the loop. > + * on our next iteration of the loop. Note that it needs > + * to be pageblock aligned even when the region itself > + * is not as move_freepages_block() can shift ahead of > + * the valid region but still depends on correct page > + * metadata. > */ > - pfn = memblock_next_valid_pfn(pfn, end_pfn) - 1; > + pfn = (memblock_next_valid_pfn(pfn, end_pfn) & > + ~(pageblock_nr_pages-1)) - 1; > #endif > continue; > } > -- > 2.16.2 > -- Michal Hocko SUSE Labs