From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx186.postini.com [74.125.245.186]) by kanga.kvack.org (Postfix) with SMTP id E2FB36B0062 for ; Tue, 5 Jun 2012 04:18:56 -0400 (EDT) From: Subject: RE: [PATCH 0/5] Some vmevent fixes... Date: Tue, 5 Jun 2012 08:16:12 +0000 Message-ID: <84FF21A720B0874AA94B46D76DB98269045EBBD8@008-AM1MPN1-003.mgdnok.nokia.com> References: <20120601122118.GA6128@lizard> <4FCC7592.9030403@kernel.org> <20120604113811.GA4291@lizard> <20120604121722.GA2768@barrios> <20120604133527.GA13650@lizard> <4FCDBC8E.1000705@kernel.org> In-Reply-To: Content-Language: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Sender: owner-linux-mm@kvack.org List-ID: To: penberg@kernel.org, minchan@kernel.org Cc: cbouatmailru@gmail.com, kosaki.motohiro@gmail.com, john.stultz@linaro.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linaro-kernel@lists.linaro.org, patches@linaro.org, kernel-team@android.com > -----Original Message----- > From: penberg@gmail.com [mailto:penberg@gmail.com] On Behalf Of ext > Pekka Enberg > Sent: 05 June, 2012 11:02 > To: Minchan Kim ... > > Next concern is that periodic timer of implementation. > > I think it would add direct hook in vmscan.c rather than peeking raw > > vmstat periodically by timer so we can control more fine-grained way > without unnecessary overhead. >=20 > If the hooks are clean and it doesn't hurt the !CONFIG_VMEVENT case, I'm > completely OK with that. On the previous iteration hooking vm was pointed as very bad idea, so in my= version I installed shrinker to handle cases when we have memory pressure. Using deferred timer with adequate timeout (0.250 ms or larger) fully suita= ble for userspace and produce adequate overhead=20 -> by nature such API should not be 100% accurate, anyhow applications cann= ot handle situation as good as kernel can provide, 0.5MB space accuracy, 10= 0ms is maximum user-space require for 64-1024MB devices. -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org