From owner-freebsd-net@FreeBSD.ORG Wed Oct 1 09:48:52 2014 Return-Path: Delivered-To: freebsd-net@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 F27B177A; Wed, 1 Oct 2014 09:48:51 +0000 (UTC) Received: from mail-lb0-x232.google.com (mail-lb0-x232.google.com [IPv6:2a00:1450:4010:c04::232]) (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 0F20484C; Wed, 1 Oct 2014 09:48:50 +0000 (UTC) Received: by mail-lb0-f178.google.com with SMTP id w7so401654lbi.37 for ; Wed, 01 Oct 2014 02:48:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:date:message-id:subject:from:to:cc:content-type; bh=8jus+cC9lVbpbSamaQAH6btlprDhdy2k39KIMqiox+I=; b=P+mJzrOM9e4UjH1kRc+IlEJb4/N8EgvNjw7QGkkIcgNuCY9kslDsMCL7BJD/bqn/Wj vXVWJeEJOvypbuMWTcrcnmiu5ijPu1u5v2x/BAO5KWfCePxUsLh/RBecIzt2htiJeDEs eQLLkQnjG0W+sTBZpwTJfnAG6EkAXm2msv5HHxmdGfHKANAefDkB9qT36FwCkUWIOvDB 1OQQJaw2OHPNJv+RWoNOPwNINtVCrN28G29/VCZIOPualVhdw3nQWvPgPIF0yxWoawdt Ekjf8jLSuQK4y0ymcxV1LEvOH6cSKv1x8S27MZxGIEKaDGR7323L4t+rBVQJPemVD2wv FeFg== MIME-Version: 1.0 X-Received: by 10.112.185.103 with SMTP id fb7mr10156847lbc.32.1412156928850; Wed, 01 Oct 2014 02:48:48 -0700 (PDT) Sender: rizzo.unipi@gmail.com Received: by 10.114.26.37 with HTTP; Wed, 1 Oct 2014 02:48:48 -0700 (PDT) Date: Wed, 1 Oct 2014 11:48:48 +0200 X-Google-Sender-Auth: ktkvZ1IHCJsrE0p3MVCM367DqVo Message-ID: Subject: individual queue blocking entire rx unit on ixgbe (Re: How do I balance bandwidth over several virtual NICs?) From: Luigi Rizzo To: Adrian Chadd , "freebsd-net@freebsd.org" Content-Type: text/plain; charset=UTF-8 X-Content-Filtered-By: Mailman/MimeDel 2.1.18-1 Cc: Elof Ofel , "Alexander V. Chernikov" X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 01 Oct 2014 09:48:52 -0000 reviving this thread: i am just running experiments on 10.1 beta3 and even setting dev.ix.*.fc=0 and flipping the interface up and down does not seem to help: if i read only from a subset of the queues, the entire rx unit stalls eventually. I need to drain all queues to keep moving. Just tested this with 8 instances of netmap-ipfw running on an 8-core machine (8 queues enabled). netmap-ipfw netmap:ix0-0 netmap:ix1-0 netmap-ipfw netmap:ix0-1 netmap:ix1-1 ... and the source on another box is blasting on multiple queues with pkt-gen -f tx -i ix0 -d 10.0.10.0-10.0.10.255 I going to look at the driver's code now to see if/how this issue can be addressed. cheers luigi On Tue, Sep 23, 2014 at 6:00 PM, Adrian Chadd wrote: > Ah, this behaviour. > > It's called DROP_EN on the intel igb / ixgbe hardware. Grep the > drivers for that particular register bit/setting. > > Set that bit for an RX queue and it'll instruct the MAC to drop frames > destined if that RX ring is full to it and keep receiving on the other > rings. Otherwise yes, receiving on that ring with the ring full cuases > the MAC to stop receiving on all rings until that ring has free space. > > You flip this on with ixgbe and igb by disabling tx/rx flowcontrol > (sysctl dev.ix|igb.X.fc=0) before configuring the interface. > > > > -a > -- -----------------------------------------+------------------------------- Prof. Luigi RIZZO, rizzo@iet.unipi.it . Dip. di Ing. dell'Informazione http://www.iet.unipi.it/~luigi/ . Universita` di Pisa TEL +39-050-2211611 . via Diotisalvi 2 Mobile +39-338-6809875 . 56122 PISA (Italy) -----------------------------------------+-------------------------------