Re: [PATCH v2 7/8] mm/memory_hotplug: Add pgprot_t to mhp_modifiers

2020-01-08 Thread Logan Gunthorpe
On 2020-01-08 5:42 a.m., Michal Hocko wrote: > On Tue 07-01-20 13:59:58, Logan Gunthorpe wrote: >> devm_memremap_pages() is currently used by the PCI P2PDMA code to create >> struct page mappings for IO memory. At present, these mappings are created >> with PAGE_KERNEL which implies setting the

Re: [PATCH v2 7/8] mm/memory_hotplug: Add pgprot_t to mhp_modifiers

2020-01-08 Thread Logan Gunthorpe
On 2020-01-08 5:39 a.m., David Hildenbrand wrote: > On 07.01.20 21:59, Logan Gunthorpe wrote: >> devm_memremap_pages() is currently used by the PCI P2PDMA code to create >> struct page mappings for IO memory. At present, these mappings are created >> with PAGE_KERNEL which implies setting the PA

Re: [PATCH v2 7/8] mm/memory_hotplug: Add pgprot_t to mhp_modifiers

2020-01-08 Thread Michal Hocko
On Tue 07-01-20 13:59:58, Logan Gunthorpe wrote: > devm_memremap_pages() is currently used by the PCI P2PDMA code to create > struct page mappings for IO memory. At present, these mappings are created > with PAGE_KERNEL which implies setting the PAT bits to be WB. However, on > x86, an mtrr registe

Re: [PATCH v2 7/8] mm/memory_hotplug: Add pgprot_t to mhp_modifiers

2020-01-08 Thread David Hildenbrand
On 07.01.20 21:59, Logan Gunthorpe wrote: > devm_memremap_pages() is currently used by the PCI P2PDMA code to create > struct page mappings for IO memory. At present, these mappings are created > with PAGE_KERNEL which implies setting the PAT bits to be WB. However, on > x86, an mtrr register will

[PATCH v2 7/8] mm/memory_hotplug: Add pgprot_t to mhp_modifiers

2020-01-07 Thread Logan Gunthorpe
devm_memremap_pages() is currently used by the PCI P2PDMA code to create struct page mappings for IO memory. At present, these mappings are created with PAGE_KERNEL which implies setting the PAT bits to be WB. However, on x86, an mtrr register will typically override this and force the cache type t