From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail203.messagelabs.com (mail203.messagelabs.com [216.82.254.243]) by kanga.kvack.org (Postfix) with ESMTP id 355DB6B00CD for ; Mon, 2 Mar 2009 01:30:00 -0500 (EST) Received: from d28relay04.in.ibm.com (d28relay04.in.ibm.com [9.184.220.61]) by e28smtp09.in.ibm.com (8.13.1/8.13.1) with ESMTP id n22673fO024993 for ; Mon, 2 Mar 2009 11:37:03 +0530 Received: from d28av03.in.ibm.com (d28av03.in.ibm.com [9.184.220.65]) by d28relay04.in.ibm.com (8.13.8/8.13.8/NCO v9.2) with ESMTP id n226U0he4153538 for ; Mon, 2 Mar 2009 12:00:00 +0530 Received: from d28av03.in.ibm.com (loopback [127.0.0.1]) by d28av03.in.ibm.com (8.13.1/8.13.3) with ESMTP id n226TquQ029929 for ; Mon, 2 Mar 2009 17:29:53 +1100 Date: Mon, 2 Mar 2009 11:59:51 +0530 From: Balbir Singh Subject: Re: [PATCH 2/4] Memory controller soft limit interface (v3) Message-ID: <20090302062951.GI11421@balbir.in.ibm.com> Reply-To: balbir@linux.vnet.ibm.com References: <20090301062959.31557.31079.sendpatchset@localhost.localdomain> <20090301063011.31557.42094.sendpatchset@localhost.localdomain> <20090302110323.1a9b9e6b.kamezawa.hiroyu@jp.fujitsu.com> <20090302044631.GE11421@balbir.in.ibm.com> <20090302143518.43f5fcc2.kamezawa.hiroyu@jp.fujitsu.com> <20090302060726.GH11421@balbir.in.ibm.com> <20090302151953.f222c761.kamezawa.hiroyu@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20090302151953.f222c761.kamezawa.hiroyu@jp.fujitsu.com> Sender: owner-linux-mm@kvack.org To: KAMEZAWA Hiroyuki Cc: linux-mm@kvack.org, Sudhir Kumar , YAMAMOTO Takashi , Bharata B Rao , Paul Menage , lizf@cn.fujitsu.com, linux-kernel@vger.kernel.org, KOSAKI Motohiro , David Rientjes , Pavel Emelianov , Dhaval Giani , Rik van Riel , Andrew Morton List-ID: * KAMEZAWA Hiroyuki [2009-03-02 15:19:53]: > On Mon, 2 Mar 2009 11:37:26 +0530 > Balbir Singh wrote: > > > * KAMEZAWA Hiroyuki [2009-03-02 14:35:18]: > > > > > On Mon, 2 Mar 2009 10:16:31 +0530 > > > Balbir Singh wrote: > > > > > > > * KAMEZAWA Hiroyuki [2009-03-02 11:03:23]: > > > > > > > > > On Sun, 01 Mar 2009 12:00:11 +0530 > > > > > Balbir Singh wrote: > > > > > > > > > > > > > > > > > From: Balbir Singh > > > > > > > > > > > > Changelog v2...v1 > > > > > > 1. Add support for res_counter_check_soft_limit_locked. This is used > > > > > > by the hierarchy code. > > > > > > > > > > > > Add an interface to allow get/set of soft limits. Soft limits for memory plus > > > > > > swap controller (memsw) is currently not supported. Resource counters have > > > > > > been enhanced to support soft limits and new type RES_SOFT_LIMIT has been > > > > > > added. Unlike hard limits, soft limits can be directly set and do not > > > > > > need any reclaim or checks before setting them to a newer value. > > > > > > > > > > > > Kamezawa-San raised a question as to whether soft limit should belong > > > > > > to res_counter. Since all resources understand the basic concepts of > > > > > > hard and soft limits, it is justified to add soft limits here. Soft limits > > > > > > are a generic resource usage feature, even file system quotas support > > > > > > soft limits. > > > > > > > > > > > I don't convice adding more logics to res_counter is a good to do, yet. > > > > > > > > > > > > > Even though it is extensible and you pay the cost only when soft > > > > limits is turned on? Can you show me why you are not convinced? > > > > > > > Inserting more codes (like "if") to res_counter itself is not welcome.. > > > I think res_counter is too complex as counter already. > > > > > > > Darn.. we better stop all code development! > > > I don't say such a thing. My point is we have to keep res_counter as light-weight > as possible. If there are alternatives, we should use that. > Any sort of new feature like this needs support from res_counters, we need to extend them to remain consistent with out design and code. Yes, if there are better alternatives, I would use them. BTW, I am working on a newer scheme to change res_counter locking, but not sure if that should come in the way of this development. -- Balbir -- 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