From: Thomas Monjalon <thomas@monjalon.net>
To: "Burakov, Anatoly" <anatoly.burakov@intel.com>
Cc: dev@dpdk.org, matan@mellanox.com, ferruh.yigit@intel.com
Subject: Re: [dpdk-dev] [PATCH] bus/vdev: reduce scope of device list lock
Date: Tue, 22 May 2018 11:20:10 +0200 [thread overview]
Message-ID: <2833093.uzJjkH71XI@xps> (raw)
In-Reply-To: <8f0eb83d-5090-c7c8-5c3d-c4eecb96e596@intel.com>
22/05/2018 11:05, Burakov, Anatoly:
> On 21-May-18 5:11 PM, Thomas Monjalon wrote:
> > The lock vdev_device_list_lock was taken before calling
> > "remove" function for the device.
> > So it prevents to remove sub-devices (as in failsafe) inside
> > its own "remove" function, because of a deadlock.
> >
> > The lock is now only protecting the device list inside
> > the bus driver.
> >
> > Fixes: 35f462839b69 ("bus/vdev: add lock on device list")
> >
> > Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
>
> Without that lock, all of this would be racy - find_dev would iterate a
> tailq that might change under its feet, and tailq_remove may be called
> with a pointer that has already been removed.
>
> How about changing the lock to a recursive lock? Failsafe would be
> removing devices from within the same thread, correct?
Yes it could work.
I will give it a try.
next prev parent reply other threads:[~2018-05-22 9:20 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-21 16:11 Thomas Monjalon
2018-05-21 16:45 ` [dpdk-dev] [PATCH v2] bus/vdev: fix " Thomas Monjalon
2018-05-21 17:28 ` Matan Azrad
2018-05-22 9:11 ` Gaëtan Rivet
2018-05-22 9:05 ` [dpdk-dev] [PATCH] bus/vdev: reduce " Burakov, Anatoly
2018-05-22 9:20 ` Thomas Monjalon [this message]
2018-05-22 11:37 ` [dpdk-dev] [PATCH v3] bus/vdev: replace device list lock by a recursive one Thomas Monjalon
2018-05-22 12:08 ` Matan Azrad
2018-05-22 13:34 ` Burakov, Anatoly
2018-05-22 14:38 ` Thomas Monjalon
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