From owner-freebsd-net@FreeBSD.ORG Wed Apr 29 05:17:11 2015 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 B534A561 for ; Wed, 29 Apr 2015 05:17:11 +0000 (UTC) Received: from mail-pd0-x22f.google.com (mail-pd0-x22f.google.com [IPv6:2607:f8b0:400e:c02::22f]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 8496818BC for ; Wed, 29 Apr 2015 05:17:11 +0000 (UTC) Received: by pdbqd1 with SMTP id qd1so17542762pdb.2 for ; Tue, 28 Apr 2015 22:17:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=date:from:to:cc:subject:message-id:mail-followup-to:references :mime-version:content-type:content-disposition:in-reply-to :user-agent; bh=bP0amH/KpEeruTjsNlv9BIv78kCP+53WG6GJkPPcEnQ=; b=U6bTUTAiQJVeUBNrXAn5YZ7AKkRXVFNPTuI5okDogD9pQDXH6U6GgVVZTMIVyJcBK4 aXdpDErfSDgtZU8DVzQ/4VhGPz1+nKCSfOi1OAEoWMydjrfOdo/4rXRkngwa3I3K8dYN i50UCLSLpLyposQE7CuO4NTwf7EkWqbY27MCOtK5POGm0b+OHxz6tWubm7/MqnZN7KC6 4rgRBjQ54cNz8fH9PwSoCDixNUIyBzzPGChx5q8ETgGERAPQrHGV2qJaeidsgkQf5sAD 735dVgJR2IGp/tTu5oanZLObOxZzRpIAyhlhrJzNKJPQAN3f/8mGR9HlOp2Aci7G/Pb3 zT6w== X-Received: by 10.68.125.130 with SMTP id mq2mr38054133pbb.121.1430284631081; Tue, 28 Apr 2015 22:17:11 -0700 (PDT) Received: from nparhar-pc (c-24-6-44-228.hsd1.ca.comcast.net. [24.6.44.228]) by mx.google.com with ESMTPSA id ho10sm16348016pbc.27.2015.04.28.22.17.09 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 28 Apr 2015 22:17:09 -0700 (PDT) Date: Tue, 28 Apr 2015 22:16:59 -0700 From: Navdeep Parhar To: Garrett Wollman Cc: Rick Macklem , freebsd-net@FreeBSD.org, Mark Schouten Subject: Re: Frequent hickups on the networking layer Message-ID: <20150429051659.GA2180@nparhar-pc> Mail-Followup-To: Garrett Wollman , Rick Macklem , freebsd-net@FreeBSD.org, Mark Schouten References: <4281350517-9417@kerio.tuxis.nl> <137094161.27589033.1430255162390.JavaMail.root@uoguelph.ca> <21824.26416.855441.21454@hergotha.csail.mit.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <21824.26416.855441.21454@hergotha.csail.mit.edu> User-Agent: Mutt/1.5.23 (2014-03-12) X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.20 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, 29 Apr 2015 05:17:11 -0000 On Wed, Apr 29, 2015 at 01:08:00AM -0400, Garrett Wollman wrote: > < said: ... > > As far as I know (just from email discussion, never used them myself), > > you can either stop using jumbo packets or switch to a different net > > interface that doesn't allocate 9K jumbo mbufs (doing the receives of > > jumbo packets into a list of smaller mbuf clusters). > > Or just hack the driver to not use them. For the Intel drivers this > is easy, and at least for the hardware I have there's no benefit to > using 9k clusters over 4k; for Chelsio it's quite a bit harder. Quite a bit harder, and entirely unnecessary these days. Recent versions of the Chelsio driver will fall back to 4K clusters automatically (and on the fly) if the system is short of 9K clusters. There are even tunables that will let you set 4K as the only cluster size that the driver should allocate. Regards, Navdeep