From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with SMTP id 36AAC600309 for ; Mon, 30 Nov 2009 23:14:25 -0500 (EST) Received: from m5.gw.fujitsu.co.jp ([10.0.50.75]) by fgwmail5.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id nB14EMwW001785 for (envelope-from kosaki.motohiro@jp.fujitsu.com); Tue, 1 Dec 2009 13:14:22 +0900 Received: from smail (m5 [127.0.0.1]) by outgoing.m5.gw.fujitsu.co.jp (Postfix) with ESMTP id 8CFF845DE4F for ; Tue, 1 Dec 2009 13:14:22 +0900 (JST) Received: from s5.gw.fujitsu.co.jp (s5.gw.fujitsu.co.jp [10.0.50.95]) by m5.gw.fujitsu.co.jp (Postfix) with ESMTP id 3C2AC45DE54 for ; Tue, 1 Dec 2009 13:14:22 +0900 (JST) Received: from s5.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s5.gw.fujitsu.co.jp (Postfix) with ESMTP id E5FB11DB803C for ; Tue, 1 Dec 2009 13:14:21 +0900 (JST) Received: from m107.s.css.fujitsu.com (m107.s.css.fujitsu.com [10.249.87.107]) by s5.gw.fujitsu.co.jp (Postfix) with ESMTP id 42E8EE18018 for ; Tue, 1 Dec 2009 13:14:21 +0900 (JST) From: KOSAKI Motohiro Subject: Re: [PATCH 2/9] ksm: let shared pages be swappable In-Reply-To: References: <20091130180452.5BF6.A69D9226@jp.fujitsu.com> Message-Id: <20091201125801.5C16.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Date: Tue, 1 Dec 2009 13:14:20 +0900 (JST) Sender: owner-linux-mm@kvack.org To: Hugh Dickins Cc: kosaki.motohiro@jp.fujitsu.com, KAMEZAWA Hiroyuki , Andrew Morton , Izik Eidus , Andrea Arcangeli , Chris Wright , linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: > > btw, I'm not sure why bellow kmem_cache_zalloc() is necessary. Why can't we > > use stack? > > Well, I didn't use stack: partly because I'm so ashamed of the pseudo-vmas > on the stack in mm/shmem.c, which have put shmem_getpage() into reports > of high stack users (I've unfinished patches to deal with that); and > partly because page_referenced_ksm() and try_to_unmap_ksm() are on > the page reclaim path, maybe way down deep on a very deep stack. > > But it's not something you or I should be worrying about: as the comment > says, this is just a temporary hack, to present a patch which gets KSM > swapping working in an understandable way, while leaving some corrections > and refinements to subsequent patches. This pseudo-vma is removed in the > very next patch. I see. thanks for kindly explanation :) -- 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