From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with ESMTP id 25AEE6B006A for ; Thu, 7 Oct 2010 04:45:37 -0400 (EDT) Date: Thu, 7 Oct 2010 10:45:29 +0200 From: Andi Kleen Subject: Re: [PATCH 3/4] HWPOISON: Report correct address granuality for AO huge page errors Message-ID: <20101007084529.GH5010@basil.fritz.box> 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> <20101007084101.GE9891@spritzera.linux.bs1.fc.nec.co.jp> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20101007084101.GE9891@spritzera.linux.bs1.fc.nec.co.jp> Sender: owner-linux-mm@kvack.org To: Naoya Horiguchi Cc: Andi Kleen , linux-kernel@vger.kernel.org, fengguang.wu@intel.com, linux-mm@kvack.org, Andi Kleen List-ID: On Thu, Oct 07, 2010 at 05:41:01PM +0900, Naoya Horiguchi wrote: > 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? Both I guess. > 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. I used compound_order(compound_head(page)) + PAGE_SHIFT now. This even works for non compound, so the special case check can be dropped. -Andi -- ak@linux.intel.com -- Speaking for myself only. -- 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