From owner-freebsd-arch@FreeBSD.ORG Tue Jan 8 11:16:57 2013 Return-Path: Delivered-To: freebsd-arch@FreeBSD.org Received: from mx1.freebsd.org (mx1.FreeBSD.org [8.8.178.115]) by hub.freebsd.org (Postfix) with ESMTP id 04BDAE2F; Tue, 8 Jan 2013 11:16:57 +0000 (UTC) (envelope-from luigi@onelab2.iet.unipi.it) Received: from onelab2.iet.unipi.it (onelab2.iet.unipi.it [131.114.59.238]) by mx1.freebsd.org (Postfix) with ESMTP id AE5FBA34; Tue, 8 Jan 2013 11:16:56 +0000 (UTC) Received: by onelab2.iet.unipi.it (Postfix, from userid 275) id 23E747300A; Tue, 8 Jan 2013 12:16:03 +0100 (CET) Date: Tue, 8 Jan 2013 12:16:03 +0100 From: Luigi Rizzo To: Alexander Motin Subject: Re: [RFC/RFT] calloutng Message-ID: <20130108111603.GA30469@onelab2.iet.unipi.it> References: <50CCAB99.4040308@FreeBSD.org> <50CE5B54.3050905@FreeBSD.org> <50D03173.9080904@FreeBSD.org> <20121225232126.GA47692@alchemy.franken.de> <50DB4EFE.2020600@FreeBSD.org> <20130106152313.GD26039@alchemy.franken.de> <20130106162049.GA3640@onelab2.iet.unipi.it> <50EBFB1F.2080708@FreeBSD.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <50EBFB1F.2080708@FreeBSD.org> User-Agent: Mutt/1.4.2.3i Cc: Davide Italiano , freebsd-arch@FreeBSD.org, FreeBSD Current , Marius Strobl X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 08 Jan 2013 11:16:57 -0000 On Tue, Jan 08, 2013 at 12:55:27PM +0200, Alexander Motin wrote: > On 06.01.2013 18:20, Luigi Rizzo wrote: ... > > I think that for the time being it would be useful to run at least > > one set of tests with kern.timecounter.alloweddeviation=0 so we can > > tell how close we get to the required timeouts > > May be just to be sure, because it should not significantly affect > results of the 1us tests, as 5% of 1us is much less then numbers we see > there. to clarify - i don't mind if we are 50-100us (absolute error) off the requested timeout for short intervals, but i want to be sure that this error can be achieved also for large requests. cheers luigi