From owner-svn-src-head@FreeBSD.ORG Thu Nov 6 23:04:32 2014 Return-Path: Delivered-To: svn-src-head@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 2CC7A3C4; Thu, 6 Nov 2014 23:04:32 +0000 (UTC) Received: from mail-wi0-x22e.google.com (mail-wi0-x22e.google.com [IPv6:2a00:1450:400c:c05::22e]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id C2FFAB22; Thu, 6 Nov 2014 23:04:31 +0000 (UTC) Received: by mail-wi0-f174.google.com with SMTP id d1so2981039wiv.1 for ; Thu, 06 Nov 2014 15:04:30 -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:message-id:subject :from:to:cc:content-type; bh=7KsMyZ22XTQzXfAmnDOsf1CgnEKy488nVjTg9pbFmS4=; b=ee1aygnKx5RQdaoAllcfEfe9YwOlGdHcpTSuSUcl16A64nqSL9ecl5/NHi/XBnVSnX WahkBSHVpfbfDRxFScV7WpQ780uDCwReX3WRi+uR+NKv3vYaqnNLnHSMUzrCYoPZQ9sh sRFvs/7druDGhhO3JnLpEKhjE1fUJgaXUF7jtueHcawISfWKAP9SPs3r7NOSN5ZKMx6p SgVmiNwjehvXHFkvrlIW1GMVyW/NlW0/7YbbI7RAOpphYFb56WPuwQr951scYIhxymoP 7TVHQTNN2oXPjjKGVBrK4kbsqHDNq0kefNM6q+JoXVky9zTWWV32cH0P4Do6XFFvD67T yOOg== MIME-Version: 1.0 X-Received: by 10.194.80.100 with SMTP id q4mr10291377wjx.15.1415315070021; Thu, 06 Nov 2014 15:04:30 -0800 (PST) Sender: adrian.chadd@gmail.com Received: by 10.216.106.136 with HTTP; Thu, 6 Nov 2014 15:04:29 -0800 (PST) In-Reply-To: References: <201410150122.s9F1Mudu083306@svn.freebsd.org> <545B55FA.6070408@FreeBSD.org> Date: Thu, 6 Nov 2014 15:04:29 -0800 X-Google-Sender-Auth: xoWt17U5OC5LCkzFwmEaKq1uLUc Message-ID: Subject: Re: svn commit: r273112 - head/sys/dev/ixgbe From: Adrian Chadd To: Ryan Stone Content-Type: text/plain; charset=UTF-8 Cc: "svn-src-head@freebsd.org" , "svn-src-all@freebsd.org" , "src-committers@freebsd.org" , "Alexander V. Chernikov" X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 06 Nov 2014 23:04:32 -0000 On 6 November 2014 09:58, Ryan Stone wrote: > On Thu, Nov 6, 2014 at 12:21 PM, Adrian Chadd wrote: >> Hm, are there any other hardware counters that we can use to see what >> was dropped? > > On the 82599 and later you need to configure the RQSMR register to map > queue pools to indices and then the QPRDC[i] register will contain the > number of drops. Ok. > Note that the 82598 doesn't support the DROPEN bit in the SRRCTL > register. There is a separate DROPEN register on the 82598, but I > have the following worrisome comment in my version of ixgbe: > > if (hw->mac.type == ixgbe_mac_82598EB) { > /* > * The DROPEN register is intended to allow us to immediately > * drop packets that cannot be DMA'ed to memory right away to > * avoid head-of-line blocking. However we have observed that > * enabling this functionality can lead to situations where a > * queue will drop every packet destined for it silently, so > * we instead accept the HOL blocking and disable the immediate > * dropping > */ > IXGBE_WRITE_REG(&adapter->hw, IXGBE_DROPEN, 0); ... even if there's ring slots? -adrian