From: "Gaëtan Rivet" <gaetan.rivet@6wind.com>
To: Thomas Monjalon <thomas@monjalon.net>
Cc: dev@dpdk.org
Subject: Re: [dpdk-dev] [PATCH] net/failsafe: do not probe device if plugged out
Date: Thu, 13 Jul 2017 10:14:39 +0200 [thread overview]
Message-ID: <20170713081439.GH11154@bidouze.vm.6wind.com> (raw)
In-Reply-To: <1868638.SUpGZpUFpc@xps>
On Thu, Jul 13, 2017 at 08:52:33AM +0200, Thomas Monjalon wrote:
> 12/07/2017 22:39, Gaëtan Rivet:
> > Hi Thomas,
> >
> > Nice idea. A few remarks below:
> >
> > On Wed, Jul 12, 2017 at 08:28:12PM +0200, Thomas Monjalon wrote:
> > > FOREACH_SUBDEV(sdev, i, dev) {
> > > if (sdev->state != DEV_PARSED)
> > > continue;
> > > da = &sdev->devargs;
> > > +
> >
> > Superfluous line.
>
> I don't think so :) It is isolating the "skip" block with its comment.
>
> > > + /* skip plugged out devices */
> > > + if (! first_init
> > > + && sdev->cmdline == NULL
> > > + && strcmp(da->bus->name, "vdev") != 0) {
> >
> > Use first_init == false instead of negation.
> > && should be at the end of the line instead of the start of the next
> > one.
>
> Yes
>
> > Indentation is wrong.
>
> No, the coding style is to put 2 tabs for continuation lines.
>
> > > + da->bus->scan();
> > > + if (bus->find_device(NULL, cmp_dev_name, da->name) == NULL)
> > > + continue; /* device not found */
> >
> > da->bus->find_device instead of bus->find_device.
> > This function cannot find the device back currently on the PCI bus,
> > blocking the plugging of VF.
> >
> > The PCI bus will scan the VF while no rte_devargs exists to
> > describe it within the global list. If the device exists, it will
> > detect it, allocate it and then set its name.
> > Without any rte_devargs, the name of a PCI device falls back to its
> > canonical name (DomBDF instead of BDF). The name comparison with
> > da->name can only succeed if the slave was declared using the DomBDF
> > format.
> >
> > The fix is to do a deep copy of the rte_devargs (the API has been
> > sent previously with the rte_devargs rework but I have since removed
> > it) and insert it using rte_eal_devargs_insert(). This is essentially
> > the solution I used for the rte_eal_hotplug_add() fix[1].
> >
> > The alternative fix is to propose an API for buses to transform device
> > names into their canonical form on demand... And it would certainly only
> > be useful for the PCI bus.
> >
> > The issue is discussed there:
> > [1]: http://dpdk.org/ml/archives/dev/2017-July/071155.html
>
> OK, I was not aware of this exact issue.
> So I will wait above fix.
The fix above will not solve this issue.
If you are waiting for a proper, general fix, I don't think it will
arrive anytime soon.
I have the rte_eal_devargs_clone and a working version that I can send
in-reply-to if you want. But that's an API extension while in RC2 so...
--
Gaëtan Rivet
6WIND
next prev parent reply other threads:[~2017-07-13 8:14 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-07-12 18:28 Thomas Monjalon
2017-07-12 20:39 ` Gaëtan Rivet
2017-07-13 6:52 ` Thomas Monjalon
2017-07-13 8:14 ` Gaëtan Rivet [this message]
2017-07-13 9:17 ` Thomas Monjalon
2017-07-18 8:39 ` Ferruh Yigit
2017-07-18 20:49 ` Thomas Monjalon
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