[dpdk-dev] [PATCH v3] eal: add manual probing option

[Gaëtan Rivet]

Hi,

On Mon, Oct 07, 2019 at 01:27:48AM +0000, Vamsi Krishna Attunuru wrote:
> 
> 
> > -----Original Message-----
> > From: dev <dev-bounces at dpdk.org> On Behalf Of Gaetan Rivet
> > Sent: Friday, October 4, 2019 6:25 PM
> > To: dev at dpdk.org; Vamsi Krishna Attunuru <vattunuru at marvell.com>
> > Cc: Gaetan Rivet <gaetan.rivet at 6wind.com>; Ferruh Yigit
> > <ferruh.yigit at intel.com>; Anatoly Burakov <anatoly.burakov at intel.com>;
> > Thomas Monjalon <thomas at monjalon.net>; Jerin Jacob Kollanukkaran
> > <jerinj at marvell.com>; David Marchand <david.marchand at redhat.com>
> > Subject: [dpdk-dev] [PATCH v3] eal: add manual probing option
> > 
> > Add a new EAL option enabling manual probing in the EAL.
> > This command line option will configure the EAL so that buses will not trigger
> > their probe step on their own.
> > 
> > Applications are then expected to hotplug devices as they see fit.
> > 
> > Devices declared on the command line by the user (using -w and --vdev), will
> > be probed using the hotplug API, in the order they are declared.
> > 
> > This has the effect of offering a way for users to control probe order of their
> > devices, for drivers requiring it.
> > 
> > Signed-off-by: Gaetan Rivet <gaetan.rivet at 6wind.com>
> > ---
> > 
> > I haven't heard many opinions on the matter, please shout if you see an
> > issue with this approach.
> > 
> > @Slava: I have tested rather quickly that it does not break anything,
> >         and that it works as intended for basic cases.
> >         Can you test it further for your use-case and tell me if it works fine?
> > 
> > Beyond the obvious difference between both probe mode, something to
> > keep in mind:
> > while using -w on invalid devices would not block (PCI) bus probing, it will
> > stop manual probing in its track. All devices need to exist and be valid device
> > IDs.
> > 
> > v2: fixed a few typos, map file (and used Travis to validate).
> > 
> >     Slava, are you able to test this patch?
> > 
> > v3: properly fixed the map file (herited 19.08 instead of 19.05).
> > 
> >     Added a function to set the probe manual from the application,
> >     without having the user do it from the command line.
> > 
> >     Stopped spamming Slava about it, Vamsi was actually the one interested in
> > it!
> 
> @Gaetan: Thanks a lot for providing this patch. I have tested it in our use cases
> and it works as expected, also verified multiple combinations by passing
> whitelisted pdevs, vdevs and mix of both. Probing sequence happens as required.
> 
> Acked-by : Vamsi Attunuru < vattunuru at marvell.com >
> Tested-by: Vamsi Attunuru < vattunuru at marvell.com >
> 
> > 
> > Standing issue worth chiming in:
> > 
> >   Currently manual-probe will cut off probing from all buses.
> >   It could be interesting to be able to only cut buses supporting hotplug,
> >   given that they are the one able to probe devices afterward.
> > 
> >   No real use-case for this right now, so leaving as-is. Might be worth
> >   considering in the future.
> > 

Any further comment for this patch? Can someone review it?

-- 
Gaëtan Rivet
6WIND