From owner-freebsd-net@FreeBSD.ORG Mon Mar 24 22:29:06 2014 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id F0B13477; Mon, 24 Mar 2014 22:29:06 +0000 (UTC) Received: from esa-jnhn.mail.uoguelph.ca (esa-jnhn.mail.uoguelph.ca [131.104.91.44]) by mx1.freebsd.org (Postfix) with ESMTP id 87DD325B; Mon, 24 Mar 2014 22:29:06 +0000 (UTC) X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AqUEAAaxMFODaFve/2dsb2JhbABZg0FXgwe4NIZkUYE3dIIlAQEBBAEBASAEJyALBRYYAgINGQIpAQkmBggHBAEcBIdYDaxTok4XgSmMegYBARs0B4JvgUkElXOECZB/g0khMXwIFyI X-IronPort-AV: E=Sophos;i="4.97,723,1389762000"; d="scan'208";a="108761347" Received: from muskoka.cs.uoguelph.ca (HELO zcs3.mail.uoguelph.ca) ([131.104.91.222]) by esa-jnhn.mail.uoguelph.ca with ESMTP; 24 Mar 2014 18:29:05 -0400 Received: from zcs3.mail.uoguelph.ca (localhost.localdomain [127.0.0.1]) by zcs3.mail.uoguelph.ca (Postfix) with ESMTP id 38FDDB403F; Mon, 24 Mar 2014 18:29:05 -0400 (EDT) Date: Mon, 24 Mar 2014 18:29:05 -0400 (EDT) From: Rick Macklem To: Julian Elischer Message-ID: <349646395.2447442.1395700145224.JavaMail.root@uoguelph.ca> In-Reply-To: <5330632E.3050505@freebsd.org> Subject: Re: 9.2 ixgbe tx queue hang MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Originating-IP: [172.17.91.209] X-Mailer: Zimbra 7.2.1_GA_2790 (ZimbraWebClient - FF3.0 (Win)/7.2.1_GA_2790) Cc: FreeBSD Net , Christopher Forgeron , Garrett Wollman , Jack Vogel , Markus Gebert X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 24 Mar 2014 22:29:07 -0000 Julian Elischer wrote: > On 3/23/14, 4:57 PM, Rick Macklem wrote: > > Christopher Forgeron wrote: > >> > >> > >> > >> > >> > >> On Sat, Mar 22, 2014 at 6:41 PM, Rick Macklem < > >> rmacklem@uoguelph.ca > >>> wrote: > >> > >> > >> Christopher Forgeron wrote: > >>> #if defined(INET) || defined(INET6) > >>> /* Initialize to max value. */ > >>> if (ifp->if_hw_tsomax == 0) > >>> ifp->if_hw_tsomax = IP_MAXPACKET; > >>> KASSERT(ifp->if_hw_tsomax <= IP_MAXPACKET && > >>> ifp->if_hw_tsomax >= IP_MAXPACKET / 8, > >>> ("%s: tsomax outside of range", __func__)); > >>> #endif > >>> > >>> > >>> Should this be the location where it's being set rather than in > >>> ixgbe? I would assume that other drivers could fall prey to this > >>> issue. > >>> > >> All of this should be prepended with "I'm an NFS guy, not a > >> networking > >> guy, so I might be wrong". > >> > >> Other drivers (and ixgbe for the 82598 chip) can handle a packet > >> that > >> is in more than 32 mbufs. (I think the 82598 handles 100, grep for > >> SCATTER > >> in *.h in sys/dev/ixgbe.) > >> > > the Xen backend can not handle mor ethan 32 segments in some versions > of Xen. > Oops, poorly worded. I should have said "Some other drivers...". Yes, there are several (I once did a find/grep, but didn't keep the output) that have this 32 limit. Also, I have no idea if the limit can easily be increased to 35 for them? (Bryan was able to do that for the virtio network driver.) rick ps: If it was just "ix" I wouldn't care as much about this. > _______________________________________________ > freebsd-net@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-net > To unsubscribe, send any mail to > "freebsd-net-unsubscribe@freebsd.org" >