From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f43.google.com (mail-wm0-f43.google.com [74.125.82.43]) by dpdk.org (Postfix) with ESMTP id 6BFA1FA40 for ; Thu, 9 Feb 2017 16:05:21 +0100 (CET) Received: by mail-wm0-f43.google.com with SMTP id c85so233642645wmi.1 for ; Thu, 09 Feb 2017 07:05:21 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=6wind-com.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:user-agent:in-reply-to :references:mime-version:content-transfer-encoding; bh=IYScghvVGDPNTRfuVTiEYrcMHbqsPQYXi15IgJQbhls=; b=CKceG/R6oi+dYEgK1nTx41ESlAlQgoADOdNMZwSEPoQRqLURTjFhftV2WBCAArpLR4 3rmuhAiuUsOgyuOGW1sKboql1RKym3yHE2tI+hK7hNUkCIl06QCT7xR1SqWwVx2pPi6K RkHSKD0TyYDte1W5ewOAAi/fxZKvCHccSMXx8diHmTjpz2mqEIxrzT+meDcaUDHQ+iRK Q1qMUR8yj0lXTt9OYUQCc5JnFUXA3XcMB5Ju7nG9TDhqgf1pJA2l7Qr3HKVPf9IO5UD3 idLc431CJXgvyUD4KYdYoytsxILoeZwHcSIkLFeegZhi3niLxoQXWRav+EDcOuTof1iE X5JQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:user-agent :in-reply-to:references:mime-version:content-transfer-encoding; bh=IYScghvVGDPNTRfuVTiEYrcMHbqsPQYXi15IgJQbhls=; b=RokjWWH+b9FDwIgIR+yTbOqMZoqv988wAGAxnHSOa2/F/XK/+wGvpHfB8jY/Qf5jZ5 DEHe5vxYhDTR/oWdEGci8MY+0E/IakgCjRwlHe/dA6BGH4wVqof2zqBn/KVi+j114Aq9 ssNRYhk74qJFeBK2bjyrMR9xfxZ+XYG17nYdfIg+8qEIaSAogGRvsbJb1rtyoqlIUWlm luT4/XhcElooyNuVwtGfByUIsr+e1n6fQ9fJfY5v9jLTi7Wh9ig2ndmFIRZTuoScLIgy fC9/jomvUjX6Zrg1MO77jV/HvEfFQOFSlV5n1nFyCIrkz/hZjkKBzfC3pyvuzHbaMGE8 O6Pg== X-Gm-Message-State: AMke39mK0G8T7VVp4Whf717Q/5JByazkrXvbahd4hQqpcArPANhrK8TZflMyhDSENJCUBNsx X-Received: by 10.223.177.134 with SMTP id q6mr3219121wra.83.1486652721166; Thu, 09 Feb 2017 07:05:21 -0800 (PST) Received: from xps13.localnet (184.203.134.77.rev.sfr.net. [77.134.203.184]) by smtp.gmail.com with ESMTPSA id o2sm18824779wra.42.2017.02.09.07.05.05 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 09 Feb 2017 07:05:05 -0800 (PST) Date: Thu, 09 Feb 2017 07:05:05 -0800 (PST) X-Google-Original-Date: Thu, 09 Feb 2017 16:05 +0100 From: Thomas Monjalon To: Stephen Hemminger , Olivier Matz Cc: dev@dpdk.org, yuanhan.liu@linux.intel.com, john.mcnamara@intel.com Message-ID: <2800951.RjD6d24Weo@xps13> User-Agent: KMail/4.14.10 (Linux/4.5.4-1-ARCH; KDE/4.14.11; x86_64; ; ) In-Reply-To: <20170206151047.155aa0aa@xeon-e3> References: <1486387013-1706-1-git-send-email-olivier.matz@6wind.com> <20170206151047.155aa0aa@xeon-e3> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Subject: Re: [dpdk-dev] [PATCH] doc: add known issue for virtio TSO with clones X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 09 Feb 2017 15:05:21 -0000 2017-02-06 15:10, Stephen Hemminger: > On Mon, 6 Feb 2017 14:16:53 +0100 > Olivier Matz wrote: > > > +**Implication**: > > + In this situation, the shared data will be modified by the driver, > > + potentially causing race conditions with the other users of the mbuf > > + data. > > This is a driver bug! The driver must check for refcount and not modify > mbuf's whose refcnt > 1. For those mbuf's it should copy the mbuf and modify > the copy. > > It is not good to force buggy refcnt handling back onto the application. > It is acceptable to document the performance impact. Everybody agree it is a bug. Unfortunately, nobody has time to work on it in this release. So it is better than nothing to document the bug. Applied, thanks