From owner-freebsd-hackers@FreeBSD.ORG Mon Aug 30 10:07:47 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 C5B1310656AE; Mon, 30 Aug 2010 10:07:47 +0000 (UTC) (envelope-from mavbsd@gmail.com) Received: from mail-fx0-f54.google.com (mail-fx0-f54.google.com [209.85.161.54]) by mx1.freebsd.org (Postfix) with ESMTP id 2B7088FC0C; Mon, 30 Aug 2010 10:07:46 +0000 (UTC) Received: by fxm4 with SMTP id 4so3593441fxm.13 for ; Mon, 30 Aug 2010 03:07:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:sender:message-id:date:from :user-agent:mime-version:to:cc:subject:references:in-reply-to :x-enigmail-version:content-type:content-transfer-encoding; bh=BOGXsMVtSkp0fvjHRoYYAXjKVzZQpzwHRn8KCsMcP3k=; b=HW/sfED3EZzik+RbAFWZxV3ewJx73UHQZ25dCMDZz1TozYdcOYoYqhZIfMmNRglB10 9ARlEa6uz6iojQKH1Iha73m+8ZYulPqZJCQGlY7fMeHritOJ3UrUB7jkTQ+V5KZO1VqD GW4av+DAGMNUhiTM1THvFeHQqnWtPcMWAW3IA= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=sender:message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:x-enigmail-version:content-type :content-transfer-encoding; b=SWeJU+CPJ/QxQ8O8Noz/V3f5SfKawpqobHWkAK/c8a2VKAfL4j3kDyjaD3hTU1V3A3 vgyYHlDL59ZAob2AY0Ch7Gp8knO1fIbt2EaRLHbpaJ9MSE+fJvgZOnHnsyySRFqHrVcy XWlkyMKPdrj1vNUMeWhsCyELEngk5hSTQ5Ebs= Received: by 10.223.124.145 with SMTP id u17mr3482601far.92.1283162865379; Mon, 30 Aug 2010 03:07:45 -0700 (PDT) Received: from mavbook2.mavhome.dp.ua (pc.mavhome.dp.ua [212.86.226.226]) by mx.google.com with ESMTPS id r4sm3229458faa.19.2010.08.30.03.07.43 (version=SSLv3 cipher=RC4-MD5); Mon, 30 Aug 2010 03:07:44 -0700 (PDT) Sender: Alexander Motin Message-ID: <4C7B82EA.2040104@FreeBSD.org> Date: Mon, 30 Aug 2010 13:07:38 +0300 From: Alexander Motin User-Agent: Thunderbird 2.0.0.23 (X11/20091212) MIME-Version: 1.0 To: gljennjohn@googlemail.com References: <4C7A5C28.1090904@FreeBSD.org> <20100830110932.23425932@ernst.jennejohn.org> In-Reply-To: <20100830110932.23425932@ernst.jennejohn.org> X-Enigmail-Version: 0.96.0 Content-Type: text/plain; charset=ISO-8859-1 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 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 10:07:47 -0000 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. -- Alexander Motin