From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760193Ab0JGIla (ORCPT ); Thu, 7 Oct 2010 04:41:30 -0400 Received: from TYO202.gate.nec.co.jp ([202.32.8.206]:48593 "EHLO tyo202.gate.nec.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760183Ab0JGIl3 (ORCPT ); Thu, 7 Oct 2010 04:41:29 -0400 Date: Thu, 7 Oct 2010 17:41:01 +0900 From: Naoya Horiguchi To: Andi Kleen Cc: linux-kernel@vger.kernel.org, fengguang.wu@intel.com, linux-mm@kvack.org, Andi Kleen Subject: Re: [PATCH 3/4] HWPOISON: Report correct address granuality for AO huge page errors Message-ID: <20101007084101.GE9891@spritzera.linux.bs1.fc.nec.co.jp> References: <1286398141-13749-1-git-send-email-andi@firstfloor.org> <1286398141-13749-4-git-send-email-andi@firstfloor.org> <20101007003120.GB9891@spritzera.linux.bs1.fc.nec.co.jp> <20101007073848.GG5010@basil.fritz.box> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-2022-jp Content-Disposition: inline In-Reply-To: <20101007073848.GG5010@basil.fritz.box> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 07, 2010 at 09:38:48AM +0200, Andi Kleen wrote: > On Thu, Oct 07, 2010 at 09:31:20AM +0900, Naoya Horiguchi wrote: > > > @@ -198,7 +199,8 @@ static int kill_proc_ao(struct task_struct *t, unsigned long addr, int trapno, > > > #ifdef __ARCH_SI_TRAPNO > > > si.si_trapno = trapno; > > > #endif > > > - si.si_addr_lsb = PAGE_SHIFT; > > > + order = PageCompound(page) ? huge_page_order(page) : PAGE_SHIFT; > > ^^^^ > > huge_page_order(page_hstate(page)) ? > > Ok. order seems to represent a least significant bit of corrupted address, so is huge_page_order() + PAGE_SHIFT or huge_page_shift() correct? And since @page can be a tail page, compound_head() is needed as Wu-san pointed out. So huge_page_shift(page_hstate(compound_head(page))) looks good for me. Thanks, Naoya Horiguchi