Messages in this thread | | | Subject | Re: [Fastboot] Re: [RFC/PATCH] Kdump: Disabling PCI interrupts in capture kernel | From | (Eric W. Biederman) | Date | 07 Jun 2005 22:38:36 -0600 |
| |
Grant Grundler <grundler@parisc-linux.org> writes:
> On Tue, Jun 07, 2005 at 12:42:42PM -0600, Eric W. Biederman wrote: > > The howto deal with an IOMMU has been sorted out but so far no one > > has actually done it. What has been discussed previously is simply > > reserving a handful of IOMMU entries, > > How? with dma_alloc_consistent() or some special hook? > I'm just curious.
We didn't get that far but I believe the idea was a special hook.
> ... > > and then only using those > > in the crash recover kernel. This is essentially what we do with DMA > > on architectures that don't have an IOMMU and it seems quite safe > > enough there. > > Yeah, in general that should be feasible. > > One might be able to trivially allocate a small, seperate IO PDIR > just for KDUMP and switch to that. Key thing is it be physically > contiguous in memory. Very little code is involved with IO Pdir > setup for both parisc and IA64. I can't speak for Alpha/sparc/ppc/et al.
Cool.
> ... > > Well we are at least capable of multitasking but that is no longer the > > primary focus. Having polling as at least an option should make > > debugging easier. Last I looked Andrews kernel hand an irqpoll option > > to do something very like this. > > You could run the itimer but I don't see why you should. > Kdump is essentially an embedded linux kernel. It really > doesn't need to be premptive multitasking either.
It is mostly a matter of minimizing differences from the norm.
> Anyway, sounds like you guys are on the right track.
Thanks. It just takes a while for the simple solutions to get there.
Eric - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |