From owner-svn-src-all@freebsd.org Tue Sep 15 18:40:28 2015 Return-Path: Delivered-To: svn-src-all@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 42739A0509D; Tue, 15 Sep 2015 18:40:28 +0000 (UTC) (envelope-from adrian.chadd@gmail.com) Received: from mail-ig0-x22a.google.com (mail-ig0-x22a.google.com [IPv6:2607:f8b0:4001:c05::22a]) (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 0AFCA1CAA; Tue, 15 Sep 2015 18:40:28 +0000 (UTC) (envelope-from adrian.chadd@gmail.com) Received: by igxx6 with SMTP id x6so18382237igx.1; Tue, 15 Sep 2015 11:40:27 -0700 (PDT) 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=kbV+IcwmNIgaKTzfr3+dDTUeK75WcTj3dKpkvh2avxM=; b=Gr9Gvno8vcf8p4vjKv8sg8Kmcf070YKRN0KJxpbPZGe76kze2DOsMRMXsCfrYbgpjV BwDagL+Ewh8jxfsA9J7D9j9xW21dDGAzF5ciQCaMjNiifHaRxJgirqdy3WTyx8Exw/nB hDRfSSuD0oD8lqt8wQ5yOe3y30wG6FyKkF8M3i0P3dgZMdjdnrBRnG3wST1pJ9p8BQXB c7vVHoU14pb+NWZEJ2vUtNNt1s6mqJXoZ4L4OGIuddUOL3f8sK7gY/ANjuajYiu54w3i 2XXPh3XGDujatBDnqpd9PrdYA1duRR3Av7NU0xF+u4DLUg4xJvk497eUEn1Z0GPJllm6 gm0g== MIME-Version: 1.0 X-Received: by 10.50.1.44 with SMTP id 12mr8316799igj.61.1442342427168; Tue, 15 Sep 2015 11:40:27 -0700 (PDT) Received: by 10.36.28.208 with HTTP; Tue, 15 Sep 2015 11:40:27 -0700 (PDT) In-Reply-To: <55F864C2.9030102@selasky.org> References: <201409220827.s8M8RRHB031526@svn.freebsd.org> <55F69093.5050807@FreeBSD.org> <55F6935C.9000000@selasky.org> <55F6A694.7020404@FreeBSD.org> <55F6A914.6050109@selasky.org> <55F6ED8F.5030402@FreeBSD.org> <55F7FE1A.3050500@selasky.org> <55F864C2.9030102@selasky.org> Date: Tue, 15 Sep 2015 11:40:27 -0700 Message-ID: Subject: Re: svn commit: r271946 - in head/sys: dev/oce dev/vmware/vmxnet3 dev/xen/netfront kern net netinet ofed/drivers/net/mlx4 sys From: Adrian Chadd To: Hans Petter Selasky Cc: =?UTF-8?Q?Roger_Pau_Monn=C3=A9?= , "src-committers@freebsd.org" , "svn-src-all@freebsd.org" , "svn-src-head@freebsd.org" Content-Type: text/plain; charset=UTF-8 X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.20 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: Tue, 15 Sep 2015 18:40:28 -0000 On 15 September 2015 at 11:34, Hans Petter Selasky wrote: > Hi Adrian, > > On 09/15/15 19:13, Adrian Chadd wrote: >> >> I know all of this. What I'm asking is different - what about the >> change(s) that broke/fixed the Xen network performance actually caused >> the change in behaviour? I know things are sensitive to how the mbufs >> are broken up - I'd like to see exactly this. > > > You need to add statistic counters to the network drivers in question, how > frequently packets are defragged and/or dropped in the TX path to figure > that out. Can we continue this discussion elsewhere? Sure thing. Yes, maybe having a per-interface histogram of mbuf / segment sizes would be good - something we can run live on a box rather than trying to use dtrace. I wonder how difficult it'd be to slip something in as part of if_transmit and ifnet.. -adrian