From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with SMTP id 208E08D0039 for ; Sun, 30 Jan 2011 19:04:59 -0500 (EST) Received: from m4.gw.fujitsu.co.jp (unknown [10.0.50.74]) by fgwmail5.fujitsu.co.jp (Postfix) with ESMTP id C44923EE0C2 for ; Mon, 31 Jan 2011 09:04:56 +0900 (JST) Received: from smail (m4 [127.0.0.1]) by outgoing.m4.gw.fujitsu.co.jp (Postfix) with ESMTP id A53EE45DE4F for ; Mon, 31 Jan 2011 09:04:56 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (s4.gw.fujitsu.co.jp [10.0.50.94]) by m4.gw.fujitsu.co.jp (Postfix) with ESMTP id 8BCF645DE50 for ; Mon, 31 Jan 2011 09:04:56 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id 7F02EEF8004 for ; Mon, 31 Jan 2011 09:04:56 +0900 (JST) Received: from m105.s.css.fujitsu.com (m105.s.css.fujitsu.com [10.249.87.105]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id 4A1B01DB803A for ; Mon, 31 Jan 2011 09:04:56 +0900 (JST) Date: Mon, 31 Jan 2011 08:58:53 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [PATCH 3/3] Provide control over unmapped pages (v4) Message-Id: <20110131085853.b09aef2d.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: References: <20110125051003.13762.35120.stgit@localhost6.localdomain6> <20110125051015.13762.13429.stgit@localhost6.localdomain6> <20110128064851.GB5054@balbir.in.ibm.com> <20110128165605.3cbe5208.kamezawa.hiroyu@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Christoph Lameter Cc: Minchan Kim , balbir@linux.vnet.ibm.com, linux-mm@kvack.org, akpm@linux-foundation.org, npiggin@kernel.dk, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, kosaki.motohiro@jp.fujitsu.com List-ID: On Fri, 28 Jan 2011 09:20:02 -0600 (CST) Christoph Lameter wrote: > On Fri, 28 Jan 2011, KAMEZAWA Hiroyuki wrote: > > > > > I see it as a tradeoff of when to check? add_to_page_cache or when we > > > > are want more free memory (due to allocation). It is OK to wakeup > > > > kswapd while allocating memory, somehow for this purpose (global page > > > > cache), add_to_page_cache or add_to_page_cache_locked does not seem > > > > the right place to hook into. I'd be open to comments/suggestions > > > > though from others as well. > > > > I don't like add hook here. > > AND I don't want to run kswapd because 'kswapd' has been a sign as > > there are memory shortage. (reusing code is ok.) > > > > How about adding new daemon ? Recently, khugepaged, ksmd works for > > managing memory. Adding one more daemon for special purpose is not > > very bad, I think. Then, you can do > > - wake up without hook > > - throttle its work. > > - balance the whole system rather than zone. > > I think per-node balance is enough... > > > I think we already have enough kernel daemons floating around. They are > multiplying in an amazing way. What would be useful is to map all > the memory management background stuff into a process. May call this memd > instead? Perhaps we can fold khugepaged into kswapd as well etc. > Making kswapd slow for whis "additional", "requested by user, not by system" work is good thing ? I think workqueue works enough well, it's scale based on workloads, if using thread is bad. Thanks, -Kame -- 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/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: email@kvack.org