From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx124.postini.com [74.125.245.124]) by kanga.kvack.org (Postfix) with SMTP id AB0DC6B0068 for ; Thu, 6 Dec 2012 21:18:23 -0500 (EST) From: Naoya Horiguchi Subject: Re: [PATCH 1/3] HWPOISON, hugetlbfs: fix warning on freeing hwpoisoned hugepage Date: Thu, 6 Dec 2012 21:18:14 -0500 Message-Id: <1354846694-6101-1-git-send-email-n-horiguchi@ah.jp.nec.com> In-Reply-To: <3908561D78D1C84285E8C5FCA982C28F1C963B5E@ORSMSX108.amr.corp.intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: Tony Luck Cc: Naoya Horiguchi , Andrew Morton , Andi Kleen , Wu Fengguang , linux-kernel@vger.kernel.org, linux-mm@kvack.org On Wed, Dec 05, 2012 at 10:13:42PM +0000, Luck, Tony wrote: > > This patch fixes the warning from __list_del_entry() which is triggered > > when a process tries to do free_huge_page() for a hwpoisoned hugepage. > > Ultimately it would be nice to avoid poisoning huge pages. Generally we know the > location of the poison to a cache line granularity (but sometimes only to a 4K > granularity) ... and it is rather inefficient to take an entire 2M page out of service. > With 1G pages things would be even worse!! Thanks for the comment. And yes, it's remaining work to be done. > It also makes life harder for applications that would like to catch the SIGBUS > and try to take their own recovery actions. Losing more data than they really > need to will make it less likely that they can do something to work around the > loss. > > Has anyone looked at how hard it might be to have the code in memory-failure.c > break up a huge page and only poison the 4K that needs to be taken out of service? This work is one of my interest and became a bit easier than used to be, because now transparent hugepage works commonly and some of code can be copied from or shared with it. Thanks, Naoya -- 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