From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx109.postini.com [74.125.245.109]) by kanga.kvack.org (Postfix) with SMTP id 70DE56B0002 for ; Wed, 20 Mar 2013 17:53:35 -0400 (EDT) Date: Wed, 20 Mar 2013 17:53:19 -0400 From: Naoya Horiguchi Message-ID: <1363816399-c6e7mofc-mutt-n-horiguchi@ah.jp.nec.com> In-Reply-To: <5148FB6C.4070202@gmail.com> References: <1361475708-25991-1-git-send-email-n-horiguchi@ah.jp.nec.com> <1361475708-25991-2-git-send-email-n-horiguchi@ah.jp.nec.com> <5148FB6C.4070202@gmail.com> Subject: Re: [PATCH 1/9] migrate: add migrate_entry_wait_huge() Mime-Version: 1.0 Content-Type: text/plain; charset=iso-2022-jp Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: owner-linux-mm@kvack.org List-ID: To: Simon Jeons Cc: linux-mm@kvack.org, Andrew Morton , Mel Gorman , Hugh Dickins , KOSAKI Motohiro , Andi Kleen , linux-kernel@vger.kernel.org On Wed, Mar 20, 2013 at 07:57:32AM +0800, Simon Jeons wrote: > Hi Naoya, > On 02/22/2013 03:41 AM, Naoya Horiguchi wrote: > >When we have a page fault for the address which is backed by a hugepage > >under migration, the kernel can't wait correctly until the migration > >finishes. This is because pte_offset_map_lock() can't get a correct > > It seems that current hugetlb_fault still wait hugetlb page under > migration, how can it work without lock 2MB memory? Hugetlb_fault() does call migration_entry_wait(), but returns immediately. So page fault happens over and over again until the migration completes. IOW, migration_entry_wait() is now broken for hugepage and doesn't work as expected. 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