Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759132Ab2FHMZe (ORCPT ); Fri, 8 Jun 2012 08:25:34 -0400 Received: from smtp.nokia.com ([147.243.1.47]:28929 "EHLO mgw-sa01.nokia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756337Ab2FHMZc (ORCPT ); Fri, 8 Jun 2012 08:25:32 -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///62gAABLpu8P//9bUA///cm3A= Date: Fri, 8 Jun 2012 12:25:11 +0000 Message-ID: <84FF21A720B0874AA94B46D76DB98269045F7D2B@008-AM1MPN1-004.mgdnok.nokia.com> References: <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> <84FF21A720B0874AA94B46D76DB98269045F7B01@008-AM1MPN1-004.mgdnok.nokia.com> <20120608103501.GA15827@lizard> <84FF21A720B0874AA94B46D76DB98269045F7C35@008-AM1MPN1-004.mgdnok.nokia.com> <20120608121334.GA20772@lizard> In-Reply-To: <20120608121334.GA20772@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 12:25:12.0420 (UTC) FILETIME=[C0579A40:01CD4571] 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 q58CPdCY025995 Content-Length: 1060 Lines: 24 > -----Original Message----- > From: ext Anton Vorontsov [mailto:anton.vorontsov@linaro.org] > Sent: 08 June, 2012 15:14 > To: Moiseichuk Leonid (Nokia-MP/Espoo) ... > Hm. I would expect that avg value for meminfo will be much worse than > vmstat (meminfo grabs some locks). > > OK, if we consider 100ms interval, then this would be like 0.1% overhead? > Not great, but still better than memcg: > > http://lkml.org/lkml/2011/12/21/487 That is difficult to win over memcg :) But in comparison to one syscall like read() for small structure for particular device the generation of meminfo is about 1000x times more expensive. > So, I guess the right approach would be to find ways to not depend on > frequent vm_stat updates (and thus reads). Agree. > userland deferred timers (and infrequent reads from vmstat) + "userland vm > pressure notifications" looks promising for the userland solution. ????{.n?+???????+%?????ݶ??w??{.n?+????{??G?????{ay?ʇڙ?,j??f???h?????????z_??(?階?ݢj"???m??????G????????????&???~???iO???z??v?^?m???? ????????I?