From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with SMTP id 11E896B006A for ; Thu, 14 Jan 2010 03:17:45 -0500 (EST) Received: from m3.gw.fujitsu.co.jp ([10.0.50.73]) by fgwmail6.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id o0E8HgRn000353 for (envelope-from kosaki.motohiro@jp.fujitsu.com); Thu, 14 Jan 2010 17:17:42 +0900 Received: from smail (m3 [127.0.0.1]) by outgoing.m3.gw.fujitsu.co.jp (Postfix) with ESMTP id 6730E2AEAA2 for ; Thu, 14 Jan 2010 17:17:39 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (s3.gw.fujitsu.co.jp [10.0.50.93]) by m3.gw.fujitsu.co.jp (Postfix) with ESMTP id 095321EF082 for ; Thu, 14 Jan 2010 17:17:38 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id DF6851DB8038 for ; Thu, 14 Jan 2010 17:17:37 +0900 (JST) Received: from m106.s.css.fujitsu.com (m106.s.css.fujitsu.com [10.249.87.106]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id 6106EE08004 for ; Thu, 14 Jan 2010 17:17:37 +0900 (JST) From: KOSAKI Motohiro Subject: Re: [PATCH v5] add MAP_UNLOCKED mmap flag In-Reply-To: <20100114080117.GL18808@redhat.com> References: <20100114162327.673E.A69D9226@jp.fujitsu.com> <20100114080117.GL18808@redhat.com> Message-Id: <20100114170247.6747.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Date: Thu, 14 Jan 2010 17:17:36 +0900 (JST) Sender: owner-linux-mm@kvack.org To: Gleb Natapov Cc: kosaki.motohiro@jp.fujitsu.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, akpm@linux-foundation.org List-ID: > > Hmm.. > > Your answer didn't match I wanted. > Then I don't get what you want. I want to know the benefit of the patch for patch reviewing. > > few additional questions. > > > > - Why don't you change your application? It seems natural way than kernel change. > There is no way to change my application and achieve what I've described > in a multithreaded app. Then, we don't recommend to use mlockall(). I don't hope to hear your conclusion, it is not objectivization. I hope to hear why you reached such conclusion. > > - Why do you want your virtual machine have mlockall? AFAIK, current majority > > virtual machine doesn't. > It is absolutely irrelevant for that patch, but just because you ask I > want to measure the cost of swapping out of a guest memory. No. if you stop to use mlockall, the issue is vanished. > > - If this feature added, average distro user can get any benefit? > > > ?! Is this some kind of new measure? There are plenty of much more > invasive features that don't bring benefits to an average distro user. > This feature can bring benefit to embedded/RT developers. I mean who get benifit? > > I mean, many application developrs want to add their specific feature > > into kernel. but if we allow it unlimitedly, major syscall become > > the trushbox of pretty toy feature soon. > > > And if application developer wants to extend kernel in a way that it > will be possible to do something that was not possible before why is > this a bad thing? I would agree with you if for my problem was userspace > solution, but there is none. The mmap interface is asymmetric in regards > to mlock currently. There is MAP_LOCKED, but no MAP_UNLOCKED. Why > MAP_LOCKED is useful then? Why? Because this is formal LKML reviewing process. I'm reviewing your patch for YOU. If there is no objective reason, I don't want to continue reviewing. -- 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