Re: [dpdk-dev] [PATCH] mempool: fix virt address mempool population

[Olivier Matz <olivier.matz@6wind.com>]

On Tue, May 15, 2018 at 08:58:06AM +0100, Burakov, Anatoly wrote:
> On 14-May-18 7:48 PM, Thomas Monjalon wrote:
> > 14/05/2018 18:06, Anatoly Burakov:
> > > Currently, populate_virt will check if mempool is already populated.
> > > This will cause inability to reserve multi-chunk mempools if
> > > contiguous memory is not a hard requirement, because if allocating
> > > all-contiguous memory fails, mempool will retry with virtual addresses
> > > and will call populate_virt. It seems that the original code never
> > > anticipated more than one non-physically contiguous area.
> > > 
> > > Fix it by removing the check in populate virt. populate_anon() function
> > > calls populate_virt() also, and it can be reasonably inferred that it is
> > > expecting that virtual area is not already populated. Even though a
> > > similar check is already in place there, also add the check that was
> > > part of populate_virt() just in case.
> > > 
> > > Fixes: aab4f62d6c1c ("mempool: support no hugepage mode")

Acked-by: Olivier Matz <olivier.matz@6wind.com>

> > If it is really the root cause, you need to add Cc: stable@dpdk.org.
> 
> Yes. It's not as pressing for previous DPDK versions because this codepath
> wasn't triggered unless --no-huge was used, but it's still a bug.

Agree we should queue it for stable, even if it's not that critical.

Thanks,
Olivier