On Wed, 2017-07-19 at 14:02 +0530, Oza Oza wrote:
> Hi All,
>  
> 1)      DPDK fails if huge-pages are not reserved. But should not it fall back
> to regular 4k pages ?

Hugepages are not just used for efficiency reasons - they're used as a way to
get DMA safe memory in user space. I wrote an extensive overview of the
challenges in this area here:

http://www.spdk.io/doc/memory.html


> 2)      And how user space should know the requirement of number of hug pages
> before-hand ?
> a.      Rather should it always be reserved before-hand in the system?, with
> that we might waste some.

I agree that this is a real usability challenge and a more dynamic memory
allocator for hugepages would be a great leap forward for both DPDK and SPDK.
Until we get to that point, you have to pre-reserve pages and you'll probably
waste some amount of memory.

>  
>  
>  
> Regards,
> Oza.
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