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From: Thomas Monjalon <thomas.monjalon@6wind.com>
To: Stephen Hemminger <stephen@networkplumber.org>,
	Olivier Matz <olivier.matz@6wind.com>
Cc: dev@dpdk.org, yuanhan.liu@linux.intel.com, john.mcnamara@intel.com
Subject: Re: [dpdk-dev] [PATCH] doc: add known issue for virtio TSO with clones
Date: Thu, 09 Feb 2017 07:05:05 -0800 (PST)	[thread overview]
Message-ID: <2800951.RjD6d24Weo@xps13> (raw)
In-Reply-To: <20170206151047.155aa0aa@xeon-e3>

2017-02-06 15:10, Stephen Hemminger:
> On Mon,  6 Feb 2017 14:16:53 +0100
> Olivier Matz <olivier.matz@6wind.com> 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

      reply	other threads:[~2017-02-09 15:05 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-02-06 13:16 Olivier Matz
2017-02-06 23:10 ` Stephen Hemminger
2017-02-09 15:05   ` Thomas Monjalon [this message]

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