Re: [PATCH] quiet down swiotlb warnings

Andi Kleen
2007-06-01T19:37:20Z

On Fri, Jun 01, 2007 at 07:12:25PM +0100, Christoph Hellwig wrote:
> On Fri, Jun 01, 2007 at 09:01:45PM +0200, Andi Kleen wrote:
> > Bad idea imho. swiotlb mappings should always lead to printk by default
> > because it is pretty dangerous.
> >
> > One possible solution for this I could think of would be to define a
> > new pci_map_sg_couldfail() or similar that doesn't warn and use a weak
> > fallback just calling pci_map_sg on other IOMMU implementations.
>
> pci_map_sg is defined to be failing when running out of ressources, which
> is perfectly fine. We don't printk on kmalloc failures either (actually

Actually we do as you point out.

> in some cases which is highly annoying and leads people to stick a
> __GFP_NOWARN into various places)

An pci_map_sg failing typically leads to an IO error and we've
always printk'ed those. Otherwise people will wonder why they
get EIO.

-Andi