From owner-freebsd-net@FreeBSD.ORG Sun Apr 22 06:49:51 2012 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 889DD106566B; Sun, 22 Apr 2012 06:49:51 +0000 (UTC) (envelope-from jfvogel@gmail.com) Received: from mail-wg0-f50.google.com (mail-wg0-f50.google.com [74.125.82.50]) by mx1.freebsd.org (Postfix) with ESMTP id E185A8FC12; Sun, 22 Apr 2012 06:49:50 +0000 (UTC) Received: by wgbds12 with SMTP id ds12so10460572wgb.31 for ; Sat, 21 Apr 2012 23:49:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=aK7I9qsF7plYeSgXVJu2JrvGH1CggK9wXmcljdDXklw=; b=eYKhnAlc7yhyNj5G5CUG4iIrfLDa4wHZrcM+a0VbNIo0GLGgfFepoDnhVliGzF1RKT eDsXR8DTboOTRzh/4AwR9M3WoDwVk58effTcHzxOHPEejFWqtZJ/7G1tcUq+ICrDrT6j S1mgZZpJ+sOzJcPQQ89drD5FBRI/ZDT+Al8+6FtN+C0OBN8+JVK6nXD5OtWT4wBOSlId fVPPO8s8Xl+OpGovX1qpP8pv+fy2z64yw5VUNm3W2Cka51LjGg/M5zU6MXYWuZjsZqaq 6NAMS+kXPbcB+VMtha5mXEw1+zHYSX9JKQSTxu+7Dy8gI4k0U2OLJDN95TH5AcS64oGt 4Zgw== MIME-Version: 1.0 Received: by 10.180.83.198 with SMTP id s6mr11170526wiy.8.1335077389836; Sat, 21 Apr 2012 23:49:49 -0700 (PDT) Received: by 10.180.3.170 with HTTP; Sat, 21 Apr 2012 23:49:49 -0700 (PDT) In-Reply-To: References: <1334705064.4486.23.camel@powernoodle-l7.corp.yahoo.com> <1334767746.3466.6.camel@powernoodle-l7.corp.yahoo.com> <1334792417.19343.11.camel@powernoodle-l7.corp.yahoo.com> <201204190822.31010.jhb@freebsd.org> Date: Sat, 21 Apr 2012 23:49:49 -0700 Message-ID: From: Jack Vogel To: Vijay Singh Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Cc: freebsd-net@freebsd.org, Luigi Rizzo , Sean Bruno , John Baldwin Subject: Re: igb(4) Raising IGB_MAX_TXD ?? 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, 22 Apr 2012 06:49:51 -0000 Yes, I'm not sure what the actual hard limit is, will check that on Monday, but you can go over 4K, it was just a limit I created. Jack On Sat, Apr 21, 2012 at 10:51 PM, Vijay Singh wrote: > >> FWIW, at my current employer we run with both rxd and txd cranked up to > 32k > >> (we had to patch the driver as you suggested) and have not had any > problems > >> doing that for a couple of years now. > > John et al, is this limit specific to igb, or is it applicable to the > ixgbe as well. From the 8.x driver code I see: > > 100/* > 101 * TxDescriptors Valid Range: 64-4096 Default Value: 256 This value is > the > 102 * number of transmit descriptors allocated by the driver. Increasing > this > 103 * value allows the driver to queue more transmits. Each descriptor is > 16 > 104 * bytes. Performance tests have show the 2K value to be optimal for top > 105 * performance. > 106 */ > 107#define DEFAULT_TXD 1024 > 108#define PERFORM_TXD 2048 > 109#define MAX_TXD 4096 > 110#define MIN_TXD 64 > > Can the igxbe be extended beyond 4k transmit descriptors well? > > -vijay >