From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx113.postini.com [74.125.245.113]) by kanga.kvack.org (Postfix) with SMTP id 05B786B0089 for ; Fri, 7 Dec 2012 17:34:15 -0500 (EST) Date: Fri, 7 Dec 2012 14:34:14 -0800 From: Andrew Morton Subject: Re: [PATCH 1/3] HWPOISON, hugetlbfs: fix warning on freeing hwpoisoned hugepage Message-Id: <20121207143414.b2d33095.akpm@linux-foundation.org> In-Reply-To: <1354895397-21736-1-git-send-email-n-horiguchi@ah.jp.nec.com> References: <878v9acn5m.fsf@linux.vnet.ibm.com> <1354895397-21736-1-git-send-email-n-horiguchi@ah.jp.nec.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Naoya Horiguchi Cc: aneesh.kumar@linux.vnet.ibm.com, Andi Kleen , Tony Luck , Wu Fengguang , linux-kernel@vger.kernel.org, linux-mm@kvack.org On Fri, 7 Dec 2012 10:49:57 -0500 Naoya Horiguchi 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. This changelog is very short. In fact it is too short, resulting in others having to ask questions about the patch. When this happens, please treat it as a sign that the changelog needs additional information - so that other readers will not feel a need to ask the same questions! I added this paragraph: : free_huge_page() can be called for hwpoisoned hugepage from : unpoison_memory(). This function gets refcount once and clears : PageHWPoison, and then puts refcount twice to return the hugepage back to : free pool. The second put_page() finally reaches free_huge_page(). Also, is the description accurate? Is the __list_del_entry() warning the only problem? Or is it the case that this bug will cause memory corruption? If so then the patch is pretty important and is probably needed in -stable as well? I haven't checked how far back in time the bug exists. -- 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