From owner-freebsd-current@FreeBSD.ORG Mon Nov 5 06:52:57 2012 Return-Path: Delivered-To: current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 9638A793 for ; Mon, 5 Nov 2012 06:52:57 +0000 (UTC) (envelope-from davide.italiano@gmail.com) Received: from mail-vb0-f54.google.com (mail-vb0-f54.google.com [209.85.212.54]) by mx1.freebsd.org (Postfix) with ESMTP id 3D5448FC0C for ; Mon, 5 Nov 2012 06:52:57 +0000 (UTC) Received: by mail-vb0-f54.google.com with SMTP id l1so7238429vba.13 for ; Sun, 04 Nov 2012 22:52:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type; bh=cvncGtNGHsgdK/HVx07zEVImENQQ4RZ7PqSgBgofKhA=; b=kDynITC7wkwg0UAwAJ1MwDHEjE3BR0V1yImwEWBx8MpNBu9eTipPP5r2umVRzI8Oha IK/gRtwAn6RsbKAhNiGVI/qebSPUkTNhf8aVtFMblipEvfyi0JwJwHL693GcY1yab592 gES0q3a+V2UUSt7z5X15la9F1qMJALtboDvIR7EY1ip56PwViKay9S+v9q7Ca7OPzftT YAsb3ieP62YX+2skjYGbIL/HEn3NGREbuVAOSzbA+X+t+5GCEUv/Cvhuo7radGTnU9On zttLg/rro/f0MSLR2b33MHfPm6A1aPSXnk8IO0tSg8f0hFJduxInP/ZdrSE1SgKcx3o9 yovw== MIME-Version: 1.0 Received: by 10.52.99.103 with SMTP id ep7mr7759950vdb.17.1352098376512; Sun, 04 Nov 2012 22:52:56 -0800 (PST) Sender: davide.italiano@gmail.com Received: by 10.58.247.132 with HTTP; Sun, 4 Nov 2012 22:52:56 -0800 (PST) Received: by 10.58.247.132 with HTTP; Sun, 4 Nov 2012 22:52:56 -0800 (PST) In-Reply-To: <50975F6F.6010907@rewt.org.uk> References: <509758B8.1000409@rewt.org.uk> <50975F6F.6010907@rewt.org.uk> Date: Mon, 5 Nov 2012 07:52:56 +0100 X-Google-Sender-Auth: 6BscRDXse5orZtrlBHOqETnKkpQ Message-ID: Subject: Re: Dynamic Ticks/HZ From: Davide Italiano To: Joe Holden Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.14 Cc: current@freebsd.org X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 05 Nov 2012 06:52:57 -0000 On Nov 4, 2012 10:40 PM, "Joe Holden" wrote: > > Davide Italiano wrote: >> >> On Mon, Nov 5, 2012 at 7:12 AM, Joe Holden wrote: >>> >>> Hi guys, >>> >>> Has some default changed between 9.1-RC2 and HEAD? >>> >>> On identical machines, one with 9.1-RC2 and one with HEAD from yesterday >>> (GENERIC) I see the following in systat -v: >>> >>> 9.1: >>> 65 cpu0:timer >>> 10 cpu1:timer >>> >>> HEAD: >>> 1127 cpu0:timer >>> 22 cpu1:timer >>> >>> These are Supermicro i3 boxes and as far as I can see they have matching >>> BIOS config. >>> >>> Thanks, >>> J >>> _______________________________________________ >>> freebsd-current@freebsd.org mailing list >>> http://lists.freebsd.org/mailman/listinfo/freebsd-current >>> To unsubscribe, send any mail to " freebsd-current-unsubscribe@freebsd.org" >> >> >> Which is your refresh rate for systat? >> I generally measure sampling every one second (i.e. systat -vm 1). >> Also, are you making your measurements when the system is idle? >> In order to trace the source(s) of these interrupts you might consider >> to collect data via KTR. >> > > I'm also using a one second refresh rate, the system is entirely idle and the interupt rate is almost entirely static at 1127, occasionally it will drop to 1119. > > From what I understand the timer is hz/ticks which became dynamic in 9.0, although that behaviour doesn't appear to be in HEAD anymore, at least on this hardware. > > Thanks, > J It should be available, AFAIK. As I can see from your previous post you get about 20 interrupts on cpu1. This number is about 1/100 of the value you get on a !tickless kernel. If you provide the required ktr infos, probably someone will take a look.