Re: [PATCH v4 4/8] s390/airq: use DMA memory for adapter interrupts

Halil Pasic
2019-06-12T13:34:33Z

On Wed, 12 Jun 2019 08:21:27 +0200
Cornelia Huck <cohuck@redhat.com> wrote:

> On Wed, 12 Jun 2019 02:32:31 +0200
> Halil Pasic <pasic@linux.ibm.com> wrote:
>
> > On Tue, 11 Jun 2019 18:19:44 +0200
> > Cornelia Huck <cohuck@redhat.com> wrote:
> >
> > > On Tue, 11 Jun 2019 16:27:21 +0200
> > > Halil Pasic <pasic@linux.ibm.com> wrote:
>
> > > > IMHO the cleanest thing to do at this stage is to check if the
> > > > airq_iv_cache is NULL and fail the allocation if it is (to preserve
> > > > previous behavior).
> > >
> > > That's probably the least invasive fix for now. Did you check whether
> > > any of the other dma pools this series introduces have a similar
> > > problem due to init not failing?
> > >
> >
> > Good question!
> >
> > I did a quick check. virtio_ccw_init() should be OK, because we don't
> > register the driver if allocation fails, so the thing is going to end
> > up dysfunctional as expected.
> >
> > If however cio_dma_pool_init() fails, then we end up with the same
> > problem with airqs, just on the !AIRQ_IV_CACHELINE code path. It can be
> > fixed analogously: make cio_dma_zalloc() fail all allocation if
> > cio_dma_pool_init() failed before.
>
> Ok, makes sense.

v5 is out with the fixes. I have no ack/r-b from you for patch 4. Would
you like to give some, or should I proceed without?

Regards,
Halil