Re: [PATCH] eal: add request to map reserved physical memory

[Srinath Mannam <srinath.mannam@broadcom.com>]

Hi Anatoly,

Our requirement is, that separate memory segment (speed memory window)
need to be allocated outside huge pages segment.
your thoughts discussed in the link (dynamic memory allocations in
DPDK) are exactly matches with our requirement.
We tried to fit our requirement in the existing memory model with
minimum changes, So we followed this approach.
Memory model in DPDK managed using socket ids. So I also attached new
memory segment to un-used socket which allows to allocate memory using
rte_malloc.

Please add me in your discussions. I am very much interested to join
in your discussions and contribute in development.

Please point me the sources in DPDK related to this part of implementation.


Thank you.


Regards,

Srinath.


On Thu, Apr 12, 2018 at 8:05 PM, Burakov, Anatoly
<anatoly.burakov@intel.com> wrote:
> On 28-Mar-18 5:51 AM, Ajit Khaparde wrote:
>>
>> From: Srinath Mannam <srinath.mannam@broadcom.com>
>>
>> Reserved physical memory is requested from kernel
>> and it will be mapped to user space.
>> This memory will be mapped to IOVA using VFIO.
>> And this memory will be provided to SPDK to allocate
>> NVMe CQs.
>>
>> Signed-off-by: Srinath Mannam <srinath.mannam@broadcom.com>
>> Signed-off-by: Scott Branden <scott.branden@broadcom.com>
>> Signed-off-by: Ajit Khaparde <ajit.khaparde@broadcom.com>
>> ---
>
>
> Hi Srinath,
>
> I've seen this kind of approach implemented before to add additional memory
> types to DPDK (redefining "unused" socket id's to mean something else), and
> i don't like it.
>
> What would be better is to design a new API to support different memory
> types. Some groundwork for this was already laid for this release (switching
> to memseg lists), but more changes will be needed down the line. My ideal
> approach would be to have pluggable memory allocators. I've outlined some of
> my thoughts on this before [1], you're welcome to join/continue that
> discussion, and make sure whatever comes out of it is going to be useful for
> all of us :) I was planning to (attempt to) restart that discussion, and
> this seems like as good an opportunity to do that as any other.
>
> Now that the memory hotplug stuff is merged, i'll hopefully get more time
> prototyping.
>
> So, as it is, it's a NACK from me, but let's work together on something
> better :)
>
> [1] http://dpdk.org/ml/archives/dev/2018-February/090937.html
>
> --
> Thanks,
> Anatoly