On Tue, Dec 02, 2014 at 01:46:48PM -0500, Konrad Rzeszutek Wilk wrote:
> On Tue, Dec 02, 2014 at 03:45:51PM +0100, Joerg Roedel wrote:
> > On Mon, Dec 01, 2014 at 03:28:54PM -0500, Konrad Rzeszutek Wilk wrote:
> > > On Fri, Nov 28, 2014 at 12:29:08PM +0100, Joerg Roedel wrote:
> > > > diff --git a/arch/x86/kernel/pci-swiotlb.c
> > > > b/arch/x86/kernel/pci-swiotlb.c
> > > > index 77dd0ad..79b2291 100644
> > > > --- a/arch/x86/kernel/pci-swiotlb.c
> > > > +++ b/arch/x86/kernel/pci-swiotlb.c
> > > > @@ -20,6 +20,14 @@ void *x86_swiotlb_alloc_coherent(struct device
> > > > *hwdev, size_t size,
> > > > {
> > > > void *vaddr;
> > > >
> > > > + /*
> > > > + * When booting a kdump kernel in high memory these allocations
> > > > are very
> > > > + * likely to fail, as there are by default only 8MB of low
> > > > memory to
> > > > + * allocate from. So disable the warnings from the allocator
> > > > when this
> > > > + * happens. SWIOTLB also implements fall-backs for failed
> > > > allocations.
> > > > + */
> > > > + flags |= __GFP_NOWARN;
> > >
> > > Should this perhaps then have 'if (kdump_kernel)' around it since
> > > the use-case seems to be kdump related?
> >
> > Hmm, I don't think this is entirely kdump specific. It can also be
> > triggered on a non-kdump kernel, it is just much more unlikely. But
> > maybe I should change the comment to something like:
> >
> > /*
> > * Don't print a warning when the first allocation attempt
> > * fails. The swiotlb_alloc_coherent() function will print a
> > * warning when the allocation of DMA memory ultimatly failed.
> > */
>
> Much better. Thank you.
> >
> > This takes the kdump-specifics out of this change (in the end
> > kdump-kernel loaded high is just a case where this failure is much more
> > likely).
>
> <nods>
Okay, thanks. I'll update the patch.
Joerg
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
