Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934017Ab2FHI5q (ORCPT ); Fri, 8 Jun 2012 04:57:46 -0400 Received: from smtp.nokia.com ([147.243.1.48]:16645 "EHLO mgw-sa02.nokia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932218Ab2FHI5o (ORCPT ); Fri, 8 Jun 2012 04:57:44 -0400 From: To: CC: , , , , , , , , Subject: RE: [PATCH 2/5] vmevent: Convert from deferred timer to deferred work Thread-Topic: [PATCH 2/5] vmevent: Convert from deferred timer to deferred work Thread-Index: AQHNP/HM8KMmZkc4xkKq2ZDXaeCP2Zbvq0sAgAA7gACAACLOoP//7gqAgAAk2GD//+b9AIAAJPtQ Date: Fri, 8 Jun 2012 08:57:13 +0000 Message-ID: <84FF21A720B0874AA94B46D76DB98269045F7B01@008-AM1MPN1-004.mgdnok.nokia.com> References: <20120601122118.GA6128@lizard> <1338553446-22292-2-git-send-email-anton.vorontsov@linaro.org> <4FD170AA.10705@gmail.com> <20120608065828.GA1515@lizard> <84FF21A720B0874AA94B46D76DB98269045F7890@008-AM1MPN1-004.mgdnok.nokia.com> <20120608075844.GA6362@lizard> <84FF21A720B0874AA94B46D76DB98269045F7A24@008-AM1MPN1-004.mgdnok.nokia.com> <20120608084105.GA9883@lizard> In-Reply-To: <20120608084105.GA9883@lizard> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [172.22.0.61] Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 X-OriginalArrivalTime: 08 Jun 2012 08:57:15.0054 (UTC) FILETIME=[B340A4E0:01CD4554] X-Nokia-AV: Clean Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by nfs id q588vphd025118 Content-Length: 1170 Lines: 24 > -----Original Message----- > From: ext Anton Vorontsov [mailto:anton.vorontsov@linaro.org] > Sent: 08 June, 2012 11:41 ... > > Right. It but it has drawbacks as well e.g. ensure that daemon scheduled > properly and propagate reaction decision outside ulmkd. > > No, ulmkd itself propagates the decision (i.e. it kills processes). That is a decision "select & kill" :) Propagation of this decision required time. Not all processes could be killed. You may stuck in killing in some cases. ... > In ulmkd I don't use timers at all, and by "watcher" I mean the some > userspace daemon that receives lowmemory/pressure events (in our case it > is ulmkd). Thanks for info. > If we start "polling" on /proc/vmstat via userland deferred timers, that would > be a single timer, just like in vmevent case. So, I'm not sure what is the > difference?.. Context switches, parsing, activity in userspace even memory situation is not changed. In kernel space you can use sliding timer (increasing interval) + shinker. ????{.n?+???????+%?????ݶ??w??{.n?+????{??G?????{ay?ʇڙ?,j??f???h?????????z_??(?階?ݢj"???m??????G????????????&???~???iO???z??v?^?m???? ????????I?