Re: [PATCH kernel v11 27/34] powerpc/powernv: Implement multilevel TCE tables

2015-06-03 Thread Alexey Kardashevskiy
On 06/02/2015 09:50 AM, David Gibson wrote: On Fri, May 29, 2015 at 06:44:51PM +1000, Alexey Kardashevskiy wrote: TCE tables might get too big in case of 4K IOMMU pages and DDW enabled on huge guests (hundreds of GB of RAM) so the kernel might be unable to allocate contiguous chunk of physical

Re: [PATCH kernel v11 27/34] powerpc/powernv: Implement multilevel TCE tables

2015-06-03 Thread David Gibson
On Wed, Jun 03, 2015 at 09:27:10PM +1000, Alexey Kardashevskiy wrote: On 06/02/2015 09:50 AM, David Gibson wrote: On Fri, May 29, 2015 at 06:44:51PM +1000, Alexey Kardashevskiy wrote: TCE tables might get too big in case of 4K IOMMU pages and DDW enabled on huge guests (hundreds of GB of RAM)

Re: [PATCH kernel v11 27/34] powerpc/powernv: Implement multilevel TCE tables

2015-06-01 Thread David Gibson
On Fri, May 29, 2015 at 06:44:51PM +1000, Alexey Kardashevskiy wrote: TCE tables might get too big in case of 4K IOMMU pages and DDW enabled on huge guests (hundreds of GB of RAM) so the kernel might be unable to allocate contiguous chunk of physical memory to store the TCE table. To address

[PATCH kernel v11 27/34] powerpc/powernv: Implement multilevel TCE tables

2015-05-29 Thread Alexey Kardashevskiy
TCE tables might get too big in case of 4K IOMMU pages and DDW enabled on huge guests (hundreds of GB of RAM) so the kernel might be unable to allocate contiguous chunk of physical memory to store the TCE table. To address this, POWER8 CPU (actually, IODA2) supports multi-level TCE tables, up to