From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756663Ab0F3Pzg (ORCPT ); Wed, 30 Jun 2010 11:55:36 -0400 Received: from mx1.redhat.com ([209.132.183.28]:7239 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754677Ab0F3Pzd (ORCPT ); Wed, 30 Jun 2010 11:55:33 -0400 Date: Wed, 30 Jun 2010 17:55:06 +0200 From: Andrea Arcangeli To: Rik van Riel Cc: akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kosaki.motohiro@jp.fujitsu.com Subject: Re: [PATCH -mm] rmap: add exclusive page to private anon_vma on swapin Message-ID: <20100630155506.GV16195@random.random> References: <20100630113710.3b376e6a@annuminas.surriel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100630113710.3b376e6a@annuminas.surriel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jun 30, 2010 at 11:37:10AM -0400, Rik van Riel wrote: > @@ -2714,10 +2715,11 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma, > if ((flags & FAULT_FLAG_WRITE) && reuse_swap_page(page)) { > pte = maybe_mkwrite(pte_mkdirty(pte), vma); > flags &= ~FAULT_FLAG_WRITE; > + exclusive = 1; > } Agreed. it's something I considered doing too but I deferred until I figure out all the mess with ksm-copy. I'll test your patch but it should make no practical difference to my workload. I also had a patch in my queue that changes this path which I deferred as well for now. ==== Subject: set VM_FAULT_WRITE in do_swap_page From: Andrea Arcangeli Set the flag if do_swap_page is decowing the page the same way do_wp_page would too. Signed-off-by: Andrea Arcangeli --- diff --git a/mm/memory.c b/mm/memory.c --- a/mm/memory.c +++ b/mm/memory.c @@ -2673,6 +2686,7 @@ static int do_swap_page(struct mm_struct if ((flags & FAULT_FLAG_WRITE) && reuse_swap_page(page)) { pte = maybe_mkwrite(pte_mkdirty(pte), vma); flags &= ~FAULT_FLAG_WRITE; + ret |= VM_FAULT_WRITE; } flush_icache_page(vma, page); set_pte_at(mm, address, page_table, pte);