From owner-freebsd-hardware@FreeBSD.ORG Thu Sep 6 14:45:27 2012 Return-Path: Delivered-To: freebsd-hardware@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 81B841065673; Thu, 6 Sep 2012 14:45:27 +0000 (UTC) (envelope-from ndenev@gmail.com) Received: from mail-bk0-f54.google.com (mail-bk0-f54.google.com [209.85.214.54]) by mx1.freebsd.org (Postfix) with ESMTP id C971B8FC0C; Thu, 6 Sep 2012 14:45:26 +0000 (UTC) Received: by bkcje9 with SMTP id je9so935360bkc.13 for ; Thu, 06 Sep 2012 07:45:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=subject:mime-version:content-type:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to:x-mailer; bh=P6QGeliBiLXTWwSFVM0KLuo1S7slOMaAfLAB+2Hp8JA=; b=BRSOYKhO04obfCk6bo0clDPqfUdpbn047diAosZslhE8wbB75jWe9R+xWf8PoRB+zY 5PhIlxGMPcS5uN6nEsiAOIR8kVHxt9eySlZyEgiusHOaVC3yvbFiTEUJRhCiYdRG0i7E MeWVO99B4g0SFxc6zBDnHM6lYFgNXeSau4K8UtPKwIcn1b3UkOCsswe12zUj1jIAAGGP XekMYWwFfkwW+r8TRLIsDgyPs2/8pcIlSNhZOq/OS1XM10Ui5qzcE/+U6KAclr1vKDb3 7puYvJON+IB4saQxl6nmPI5kTYxmqs56oREFIYFFMvWmByklipRZEKjFhOmm0brGPNVs 0XDg== Received: by 10.204.13.82 with SMTP id b18mr1131544bka.118.1346942725455; Thu, 06 Sep 2012 07:45:25 -0700 (PDT) Received: from [10.0.0.86] ([93.152.184.10]) by mx.google.com with ESMTPS id y20sm1486405bkv.11.2012.09.06.07.45.23 (version=TLSv1/SSLv3 cipher=OTHER); Thu, 06 Sep 2012 07:45:24 -0700 (PDT) Mime-Version: 1.0 (Mac OS X Mail 6.0 \(1486\)) Content-Type: text/plain; charset=iso-8859-1 From: Nikolay Denev In-Reply-To: <201209041213.10931.jhb@freebsd.org> Date: Thu, 6 Sep 2012 17:45:21 +0300 Content-Transfer-Encoding: quoted-printable Message-Id: <8876AEF9-0D0E-42A1-9B83-F2F7D36D7B7F@gmail.com> References: <201209041213.10931.jhb@freebsd.org> To: John Baldwin X-Mailer: Apple Mail (2.1486) Cc: Andy Young , freebsd-hardware@freebsd.org Subject: Re: What is rx_processing_limit sysctl for Intel igb NIC driver? X-BeenThere: freebsd-hardware@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: General discussion of FreeBSD hardware List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 06 Sep 2012 14:45:27 -0000 On Sep 4, 2012, at 7:13 PM, John Baldwin wrote: > On Sunday, September 02, 2012 10:41:15 pm Andy Young wrote: >> I am tuning our server that has an Intel 82576 gigabit NIC using the = igb >> driver. I see a lot of posts on the net where people bump the >> rx_processing_limit sysctl from the default value of 100 to 4096. Can >> anyone tell me what this is intended to do? >=20 > If you have multiple devices sharing an IRQ with igb (and thus are not = using=20 > MSI or MSI-X), it forces the driver to more-or-less cooperatively = schedule=20 > with the other interrupts on the same IRQ. However, since igb uses a = fast=20 > interrupt handler and a task on a dedicated taskqueue in the non-MSI = case now,=20 > I think it doesn't even do that. It should probably be set to -1 = (meaning > unlimited) in just about all cases now. >=20 > --=20 > John Baldwin > _______________________________________________ > freebsd-hardware@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-hardware > To unsubscribe, send any mail to = "freebsd-hardware-unsubscribe@freebsd.org" And setting it to -1 gave a nice performance improvement in some tests = that I did recently. AFAIR only after setting this to -1 I was able to reach 10gig speed = using iperf on two directly connected machines with ix(4) 82599=