From owner-freebsd-hackers@FreeBSD.ORG Mon Aug 30 10:11:52 2010 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id A847A1065693; Mon, 30 Aug 2010 10:11:52 +0000 (UTC) (envelope-from gljennjohn@googlemail.com) Received: from mail-bw0-f54.google.com (mail-bw0-f54.google.com [209.85.214.54]) by mx1.freebsd.org (Postfix) with ESMTP id 9E2888FC14; Mon, 30 Aug 2010 10:11:51 +0000 (UTC) Received: by bwz20 with SMTP id 20so4213977bwz.13 for ; Mon, 30 Aug 2010 03:11:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=gamma; h=domainkey-signature:received:received:date:from:to:cc:subject :message-id:in-reply-to:references:reply-to:x-mailer:mime-version :content-type:content-transfer-encoding; bh=j4hpdxucCCnYKG3ESWmHXIYc1ufCpuSU6nmeRcfb6bY=; b=JOnplvpeYofJwkU44zSnTYzQCBo2nqVIYwprOSHlGdjJyriITyoAjrnOas9l6zxPPY FFgChqMIjIhekh1U0lpH6xJ6Gf3FgVvGvC3gMNPF+9irrKZnh5A9hXSa8PAO3H4NzZOJ MEp4mr2HmDLDq8emjeZlWjNrIyE/h6CZMe+OI= DomainKey-Signature: a=rsa-sha1; c=nofws; d=googlemail.com; s=gamma; h=date:from:to:cc:subject:message-id:in-reply-to:references:reply-to :x-mailer:mime-version:content-type:content-transfer-encoding; b=FiFmRiLRRboVVZsqfFrQFoU2OzBNMbYg09xvTMefHmAq3uwzNQTHijKVF8NVNueZfJ tANIsTCRd0hrp3qbj0c/2xxY2vEMJFzS4CkAEJdUvdwEnY4iMIiAW+tEIpoca+zuW8HD vOKDY24r9HBVqCdq3aTAU82Jz1iB+UzJOpeuU= Received: by 10.204.63.14 with SMTP id z14mr3034927bkh.174.1283163110779; Mon, 30 Aug 2010 03:11:50 -0700 (PDT) Received: from ernst.jennejohn.org (p578E3A7B.dip.t-dialin.net [87.142.58.123]) by mx.google.com with ESMTPS id y2sm5073393bkx.20.2010.08.30.03.11.49 (version=TLSv1/SSLv3 cipher=RC4-MD5); Mon, 30 Aug 2010 03:11:50 -0700 (PDT) Date: Mon, 30 Aug 2010 12:11:48 +0200 From: Gary Jennejohn To: Alexander Motin Message-ID: <20100830121148.11926306@ernst.jennejohn.org> In-Reply-To: <4C7B82EA.2040104@FreeBSD.org> References: <4C7A5C28.1090904@FreeBSD.org> <20100830110932.23425932@ernst.jennejohn.org> <4C7B82EA.2040104@FreeBSD.org> X-Mailer: Claws Mail 3.7.6 (GTK+ 2.18.7; amd64-portbld-freebsd9.0) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: freebsd-hackers@freebsd.org, FreeBSD-Current Subject: Re: One-shot-oriented event timers management X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: gljennjohn@googlemail.com List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 30 Aug 2010 10:11:52 -0000 On Mon, 30 Aug 2010 13:07:38 +0300 Alexander Motin wrote: > Gary Jennejohn wrote: > > Hmm. I applied your patches and am now running the new kernel. But I > > only installed the new kernel and didn't do make buildworld installworld. > > > > Mu systat -vm 1 doesn't look anything like yours. I'm seeing about 2300 > > interrupts per second and most of those are coming from the hpet timers: > > > > 1122 hpet0:t0 > > 1124 hpet0:t1 > > It means 1000Hz of hardclock (hz) events mixed with 127Hz of statclock > (stathz) events. HPET timer here works in one-shot mode handling it. > > > So, what else did you do to reduce interrupts so much? > > > > Ah, I think I see it now. My desktop has only C1 enabled. Is that it? > > Unfortunately, it appears that only C1 is supported :( > > Yes, as I have said, at this moment empty ticks skipped only while CPU > is in C2/C3 states. In C1 state there is no way to handle lost events on > wake up. While it may be not very dangerous, it is not very good. > Too bad. I'd say that systems which are limited to C1 don't benefit much (or not at all) from your changes. -- Gary Jennejohn