Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757048Ab2FHG5w (ORCPT ); Fri, 8 Jun 2012 02:57:52 -0400 Received: from mail-qa0-f46.google.com ([209.85.216.46]:35033 "EHLO mail-qa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753301Ab2FHG5u (ORCPT ); Fri, 8 Jun 2012 02:57:50 -0400 Message-ID: <4FD1A26B.7010601@gmail.com> Date: Fri, 08 Jun 2012 02:57:47 -0400 From: KOSAKI Motohiro User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7; rv:12.0) Gecko/20120428 Thunderbird/12.0.1 MIME-Version: 1.0 To: Pekka Enberg CC: KOSAKI Motohiro , Anton Vorontsov , Minchan Kim , Leonid Moiseichuk , John Stultz , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linaro-kernel@lists.linaro.org, patches@linaro.org, kernel-team@android.com Subject: Re: [PATCH 0/5] Some vmevent fixes... References: <20120507121527.GA19526@lizard> <4FA82056.2070706@gmail.com> <20120601122118.GA6128@lizard> <4FCC7592.9030403@kernel.org> <20120604113811.GA4291@lizard> <4FCD14F1.1030105@gmail.com> <4FD177BD.1070004@gmail.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1138 Lines: 25 (6/8/12 2:54 AM), Pekka Enberg wrote: > On Fri, Jun 8, 2012 at 6:55 AM, KOSAKI Motohiro > wrote: >>> For some cases, yes, but probably not for all. >>> >>> For example, if userspace doesn't know about "about to swap real soon" >>> condition, it can continue to grow its caches making >>> fallocate(VOLATILE) pretty much useless. >> >> Fair enough. But, Please consider your scenario don't need vmevent(2), >> cat /proc/meminfo works enough. Only dropping activity need a quick work >> and just in time notification. cache growing limitation don't need. > > Why do you keep bringing this up? Yes, you might get away with polling > /proc/meminfo or /proc/vmstat for some specific cases. It does not > make it a proper generic solution to the problem "vmevent" ABI tries > to address. Guys, current vmevent _is_ a polling interface. It only is wrapped kernel timer. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/