[dpdk-dev] What is the status of mempool manager?

[dpdk-dev] What is the status of mempool manager?

[Jan Viktorin]

Hello,

I was trying to find out the status of the mempool rework and found
this 36-pieces long patch set:

http://dpdk.org/ml/archives/dev/2016-April/037464.html

(I failed to apply it to 16.04, 2.1.0, current HEAD.)

and some bits around:

http://dpdk.org/ml/archives/dev/2016-May/038390.html
http://dpdk.org/ml/archives/dev/2016-April/037509.html
http://dpdk.org/ml/archives/dev/2016-April/037457.html
http://dpdk.org/ml/archives/dev/2016-April/036979.html

...but I am confused.

I am trying to find out how to write a custom memory pool based on
the uio_dmem_genirq driver. It provides DMA memory via the UIO API
(maps).

If I have a PMD running of top of this UIO, I need to implement a
custom allocator that gets memory from the dev->mem_resource (with
the mappings preloaded from the UIO by EAL).

This is related to the SoC infra as given here:

http://dpdk.org/ml/archives/dev/2016-May/038486.html

Any idea how to start with this?

Regards
Jan

-- 
   Jan Viktorin                  E-mail: Viktorin@RehiveTech.com
   System Architect              Web:    www.RehiveTech.com
   RehiveTech
   Brno, Czech Republic

Re: [dpdk-dev] What is the status of mempool manager?

[Olivier MATZ]

Hi Jan,

On 05/17/2016 02:34 PM, Jan Viktorin wrote:
> Hello,
>
> I was trying to find out the status of the mempool rework and found
> this 36-pieces long patch set:
>
> http://dpdk.org/ml/archives/dev/2016-April/037464.html
>
> (I failed to apply it to 16.04, 2.1.0, current HEAD.)

It should be integrated soon, as there was no comment during
some time. I'll send a new version that applies on head
+ minor cosmetic changes.

> and some bits around:
>
> http://dpdk.org/ml/archives/dev/2016-May/038390.html

I need to review this one, it's on my todo list.

> http://dpdk.org/ml/archives/dev/2016-April/037509.html

I think the code is ready to be integrated, but I was expecting
some reactions on the v4, especially some precisions about the
use cases and the needs. See in the link "Things that should
still be discussed".

> http://dpdk.org/ml/archives/dev/2016-April/037457.html

It is integrated since today ;)

> http://dpdk.org/ml/archives/dev/2016-April/036979.html

Some comments have been done by Konstantin and myself, I
think a new version will be submitted. It will be integrated
in 16.07.

> ...but I am confused.
>
> I am trying to find out how to write a custom memory pool based on
> the uio_dmem_genirq driver. It provides DMA memory via the UIO API
> (maps).
>
> If I have a PMD running of top of this UIO, I need to implement a
> custom allocator that gets memory from the dev->mem_resource (with
> the mappings preloaded from the UIO by EAL).
>
> This is related to the SoC infra as given here:
>
> http://dpdk.org/ml/archives/dev/2016-May/038486.html
>
> Any idea how to start with this?

I think your feedback would be very valuable.

The "external mempool manager" series allows to register new
handler that replaces the internal ring storing the objects. It
does not change the way the memory is allocated.

The big patchset introduce new way of allocating memory used by
memory pool (no need to be virtually contiguous anymore). You
could throw an eye on rte_mempool_populate*() functions that
populate a mempool with memory for storing the objects.

I'm not sure I'm getting your exact needs.
Do you need to populate a ring-based mempool with specific memory,
retrieved from UIO API?
Do you need to replace the default internal ring by something else?
Do you need to access the mempool from the hardware?

Regards,
Olivier

Re: [dpdk-dev] What is the status of mempool manager?

[Jan Viktorin]

Hello Olivier...

On Tue, 17 May 2016 15:56:32 +0200
Olivier MATZ <olivier.matz@6wind.com> wrote:

> Hi Jan,
> 
> On 05/17/2016 02:34 PM, Jan Viktorin wrote:
> > Hello,
> >
> > I was trying to find out the status of the mempool rework and found
> > this 36-pieces long patch set:
> >
> > http://dpdk.org/ml/archives/dev/2016-April/037464.html
> >
> > (I failed to apply it to 16.04, 2.1.0, current HEAD.)  
> 
> It should be integrated soon, as there was no comment during
> some time. I'll send a new version that applies on head
> + minor cosmetic changes.

Cool ;).

> 
> > and some bits around:
> >
> > http://dpdk.org/ml/archives/dev/2016-May/038390.html  
> 
> I need to review this one, it's on my todo list.
> 
> > http://dpdk.org/ml/archives/dev/2016-April/037509.html  
> 
> I think the code is ready to be integrated, but I was expecting
> some reactions on the v4, especially some precisions about the
> use cases and the needs. See in the link "Things that should
> still be discussed".
> 
> > http://dpdk.org/ml/archives/dev/2016-April/037457.html  
> 
> It is integrated since today ;)
> 
> > http://dpdk.org/ml/archives/dev/2016-April/036979.html  
> 
> Some comments have been done by Konstantin and myself, I
> think a new version will be submitted. It will be integrated
> in 16.07.

Thanks for the summary.

> 
> > ...but I am confused.
> >
> > I am trying to find out how to write a custom memory pool based on
> > the uio_dmem_genirq driver. It provides DMA memory via the UIO API
> > (maps).
> >
> > If I have a PMD running of top of this UIO, I need to implement a
> > custom allocator that gets memory from the dev->mem_resource (with
> > the mappings preloaded from the UIO by EAL).
> >
> > This is related to the SoC infra as given here:
> >
> > http://dpdk.org/ml/archives/dev/2016-May/038486.html
> >
> > Any idea how to start with this?  
> 
> I think your feedback would be very valuable.

OK, CC me.

> 
> The "external mempool manager" series allows to register new
> handler that replaces the internal ring storing the objects. It
> does not change the way the memory is allocated.
> 
> The big patchset introduce new way of allocating memory used by
> memory pool (no need to be virtually contiguous anymore). You
> could throw an eye on rte_mempool_populate*() functions that
> populate a mempool with memory for storing the objects.

Thanks for this hint. I've already noticed this function...

> 
> I'm not sure I'm getting your exact needs.
> Do you need to populate a ring-based mempool with specific memory,
> retrieved from UIO API?

Probably yes.

> Do you need to replace the default internal ring by something else?

I don't think so.

> Do you need to access the mempool from the hardware?

No.

Thanks
Jan

> 
> Regards,
> Olivier



-- 
   Jan Viktorin                  E-mail: Viktorin@RehiveTech.com
   System Architect              Web:    www.RehiveTech.com
   RehiveTech
   Brno, Czech Republic