From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io0-f170.google.com (mail-io0-f170.google.com [209.85.223.170]) by kanga.kvack.org (Postfix) with ESMTP id 3866282F65 for ; Mon, 19 Oct 2015 05:58:51 -0400 (EDT) Received: by iofz202 with SMTP id z202so39639128iof.2 for ; Mon, 19 Oct 2015 02:58:51 -0700 (PDT) Received: from mail-pa0-x22e.google.com (mail-pa0-x22e.google.com. [2607:f8b0:400e:c03::22e]) by mx.google.com with ESMTPS id qf9si12897491igb.61.2015.10.19.02.58.50 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 19 Oct 2015 02:58:50 -0700 (PDT) Received: by pabrc13 with SMTP id rc13so186979113pab.0 for ; Mon, 19 Oct 2015 02:58:50 -0700 (PDT) Date: Mon, 19 Oct 2015 19:01:50 +0900 From: Minchan Kim Subject: Re: [PATCH 0/5] MADV_FREE refactoring and fix KSM page Message-ID: <20151019100150.GA5194@bbox> References: <1445236307-895-1-git-send-email-minchan@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1445236307-895-1-git-send-email-minchan@kernel.org> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Hugh Dickins , Rik van Riel , Mel Gorman , Michal Hocko , Johannes Weiner , "Kirill A. Shutemov" , Vlastimil Babka On Mon, Oct 19, 2015 at 03:31:42PM +0900, Minchan Kim wrote: > Hello, it's too late since I sent previos patch. > https://lkml.org/lkml/2015/6/3/37 > > This patch is alomost new compared to previos approach. > I think this is more simple, clear and easy to review. > > One thing I should notice is that I have tested this patch > and couldn't find any critical problem so I rebased patchset > onto recent mmotm(ie, mmotm-2015-10-15-15-20) to send formal > patchset. Unfortunately, I start to see sudden discarding of > the page we shouldn't do. IOW, application's valid anonymous page > was disappeared suddenly. > > When I look through THP changes, I think we could lose > dirty bit of pte between freeze_page and unfreeze_page > when we mark it as migration entry and restore it. > So, I added below simple code without enough considering > and cannot see the problem any more. > I hope it's good hint to find right fix this problem. > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index d5ea516ffb54..e881c04f5950 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -3138,6 +3138,9 @@ static void unfreeze_page_vma(struct vm_area_struct *vma, struct page *page, > if (is_write_migration_entry(swp_entry)) > entry = maybe_mkwrite(entry, vma); > > + if (PageDirty(page)) > + SetPageDirty(page); The condition of PageDirty was typo. I didn't add the condition. Just added. SetPageDirty(page); -- 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