[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH Xen-unstable] Balloon down memory to achive enough DMA32 memory for PV guests with PCI pass-through to succesfully launch.
>>> Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx> 16.11.09 17:38 >>> >Perhaps an extra mechanism in the balloon driver in the Dom0 kernel >to only give back to Xen pages below the 4GB mark? And if it >fails return a failure back to Xend? > >That would solve the problem of ballooning out more than needed and >would eliminate the "oh-lets balloon out 2 more MBs and see if that >did it". Unfortunately that's something you won't easily get to work, as you can't tell Linux' page allocator that you want it to try to allocate a specific (preselected by you, i.e. the balloon driver) page. But that would be necessary here, as you would have to scan the p2m table to find suitable pages... >> >Since the SWIOTLB size is determined by the 'swiotlb' argument passed to >> >the guest, what if we scanned for that and if it has a number, calculate >> >how much memory that amounts to and use that value? The default still being >> >at 64MB. >> >> That might be an option, but is very Linux-centric. I think the amount should >> be configurable per guest if something like this is being done at all. > >How about both? Have a 'pci_mem' argument to set the default and also >check the swiotlb argument in 'extra.' If there is a 'swiotlb' argument in >'extra' use that value (computed for kilobytes of course). Oh, yes, I was thinking of one augmenting the other, of course. Jan _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-devel
|
Lists.xenproject.org is hosted with RackSpace, monitoring our |