From owner-svn-src-all@FreeBSD.ORG Thu Nov 6 17:58:32 2014 Return-Path: Delivered-To: svn-src-all@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 91BD07E9; Thu, 6 Nov 2014 17:58:32 +0000 (UTC) Received: from mail-la0-x233.google.com (mail-la0-x233.google.com [IPv6:2a00:1450:4010:c03::233]) (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 2C7B2EC; Thu, 6 Nov 2014 17:58:32 +0000 (UTC) Received: by mail-la0-f51.google.com with SMTP id q1so3109841lam.10 for ; Thu, 06 Nov 2014 09:58:30 -0800 (PST) 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=sPT7XbyUqPx6IvGyt+0z9n1HgVGuadsaD7iD+sdSSNo=; b=iSRCZOTlvhO/VF2oxG8LLLen0Ok3a9Cmcc/LI8VSEMsnSCmMUJUGQBS3ib4s2KHFze quV8ILYy6yjWWa/gvru2P1m9n2a8exXje5jBy5DqtydDGTgzAxAyBbMp+Z/3Bk5aLqDZ NZ9NH6XiYZTePOVONID4AcTCFz4slEKWsdhjgXGkoA0McSFyO0N632TY5Gm/EYV9R3VJ ROU89PK+a7/X5V6xCxcbxCPWvmYQ5O/xCKURo+5DFtR/Eq265HPXI3LpOkhdN9t3dcgq bnUNCU6UNl+Gc+53B9B1xyQaEsycbB/1aEdW4xQzn4pRJIRwK0yeSzqnej3YDB9MvOQR Jg4g== MIME-Version: 1.0 X-Received: by 10.152.36.33 with SMTP id n1mr6601845laj.6.1415296710072; Thu, 06 Nov 2014 09:58:30 -0800 (PST) Received: by 10.25.0.211 with HTTP; Thu, 6 Nov 2014 09:58:30 -0800 (PST) In-Reply-To: References: <201410150122.s9F1Mudu083306@svn.freebsd.org> <545B55FA.6070408@FreeBSD.org> Date: Thu, 6 Nov 2014 12:58:30 -0500 Message-ID: Subject: Re: svn commit: r273112 - head/sys/dev/ixgbe From: Ryan Stone To: Adrian Chadd 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-all@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 06 Nov 2014 17:58:32 -0000 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. 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);