From mboxrd@z Thu Jan  1 00:00:00 1970
From: Thomas Monjalon <thomas@monjalon.net>
Subject: Re: [dpdk-stable] [PATCH v3] net/failsafe: fix calling
	device during RMV events
Date: Thu, 18 Jan 2018 23:22:51 +0100
Message-ID: <16685617.u0SECMPC3f@xps>
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Cc: Ferruh Yigit <ferruh.yigit@intel.com>, Ophir Munk <ophirmu@mellanox.com>,
 dev@dpdk.org, Olga Shern <olgas@mellanox.com>,
 Matan Azrad <matan@mellanox.com>
To: =?ISO-8859-1?Q?Ga=EBtan?= Rivet <gaetan.rivet@6wind.com>
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29/11/2017 20:17, Ferruh Yigit:
> >>> On Thu, Oct 05, 2017 at 10:42:08PM +0000, Ophir Munk wrote:
> >>>> This commit prevents control path operations from failing after a sub
> >>>> device removal.
> >>>>
> >>>> Following are the failure steps:
> >>>> 1. The physical device is removed due to change in one of PF
> >>>> parameters (e.g. MTU) 2. The interrupt thread flags the device 3.
> >>>> Within 2 seconds Interrupt thread initializes the actual device
> >>>> removal, then every 2 seconds it tries to re-sync (plug in) the
> >>>> device. The trials fail as long as VF parameter mismatches the PF
> >>> parameter.
> >>>> 4. A control thread initiates a control operation on failsafe which
> >>>> initiates this operation on the device.
> >>>> 5. A race condition occurs between the control thread and interrupt
> >>>> thread when accessing the device data structures.
> >>>>
> >>>> This commit prevents the race condition in step 5. Before this commit
> >>>> if a device was removed and then a control thread operation was
> >>>> initiated on failsafe - in some cases failsafe called the sub device
> >>>> operation instead of avoiding it. Such cases could lead to operations
> >>> failures.
[...]
> 
> Reminder of this patch remaining from previous release.

Gaetan, what is the decision for this possible race condition?
Can we try to fix it in 18.02?