From owner-freebsd-net@FreeBSD.ORG Sun Oct 19 00:28:31 2008 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 7CE6D106568E for ; Sun, 19 Oct 2008 00:28:31 +0000 (UTC) (envelope-from sandiegobiker@gmail.com) Received: from rv-out-0506.google.com (rv-out-0506.google.com [209.85.198.230]) by mx1.freebsd.org (Postfix) with ESMTP id 50B038FC08 for ; Sun, 19 Oct 2008 00:28:31 +0000 (UTC) (envelope-from sandiegobiker@gmail.com) Received: by rv-out-0506.google.com with SMTP id b25so1055235rvf.43 for ; Sat, 18 Oct 2008 17:28:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:to :subject:in-reply-to:mime-version:content-type :content-transfer-encoding:content-disposition:references; bh=BNahnxhfLuiX4ffbJ+H1xxmJnNzd4gCeIU1fMGT/18c=; b=blpboRClxq4BkZBBf9FR3uXvVpeot7MellDIhbRpmviM3dPBEXYs7fd4JazYtVIrjk jSuFr7yXh+PEbdLxekV2BhCvmZ0pmWwxJYr1waKAoCO/xwRu39EbeV5UPWySUroMIqWf 0oINDXu1j+5isQraZHe64tR19AXiwcG4xzvzo= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:in-reply-to:mime-version :content-type:content-transfer-encoding:content-disposition :references; b=hzilZYNh3nx85wlcBvaSB9CgMkGy/9X2BryTux/yXW1JsPnYcpEAltruqVEC4OJE13 4trqLlV3MsdFw6hjaNSVPLslHCef8Ew1Qs/BXshDNIoYDTvqqRSE98KUVk1KpGA1MLVo NXGIuF3pnD6Bq8/1CL9fTEeS76YX8UM6XmNG8= Received: by 10.141.88.3 with SMTP id q3mr3669508rvl.46.1224376110686; Sat, 18 Oct 2008 17:28:30 -0700 (PDT) Received: by 10.141.37.19 with HTTP; Sat, 18 Oct 2008 17:28:30 -0700 (PDT) Message-ID: <27cb3ada0810181728w3f41e3d0pe2fca8102b0c7206@mail.gmail.com> Date: Sat, 18 Oct 2008 17:28:30 -0700 From: "Len Gross" To: "freebsd-net@freebsd.org" In-Reply-To: <27cb3ada0810181512qeab4020g912096848212ad86@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <27cb3ada0810181512qeab4020g912096848212ad86@mail.gmail.com> Subject: Re: Timers in drivers vs userland X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 19 Oct 2008 00:28:31 -0000 Slight correction; I should have said more accurate usleep, not "timer." -- Len On Sat, Oct 18, 2008 at 3:12 PM, Len Gross wrote: > If I place a timer directly in a driver (like Ethernet) will it be > subject to less jitter and more consistency than if it were in > Userland? > > I know FreeBSD is not "real time," but I need to be able to run a > polling algorithm with about 1 ms accuracy. > > Thanks in advance. > > (Please tell me if there is a better list for this question.) > > -- Len >