Re: [PATCH 14/15] mm, dax, pmem: introduce {get|put}_dev_pagemap() for dax-gup

On Fri, Oct 2, 2015 at 3:42 PM, Logan Gunthorpe wrote: > > > On 02/10/15 03:53 PM, Dan Williams wrote: >> >> Yes, this location for dev_pagemap will not work. I've since moved it >> to a union with the lru list_head since ZONE_DEVICE pages memory >> should always have an elevated page count and

Re: [PATCH 14/15] mm, dax, pmem: introduce {get|put}_dev_pagemap() for dax-gup

On 02/10/15 03:53 PM, Dan Williams wrote: Yes, this location for dev_pagemap will not work. I've since moved it to a union with the lru list_head since ZONE_DEVICE pages memory should always have an elevated page count and never land on a slab allocator lru. Oh, also, I was actually hoping

Re: [PATCH 14/15] mm, dax, pmem: introduce {get|put}_dev_pagemap() for dax-gup

Hi Dan, Good to know you've already addressed the struct page issue. We'll watch out for an updated patchset to try. On 02/10/15 03:53 PM, Dan Williams wrote: Hmm, I didn't have peer-to-peer PCI-E in mind for this mechanism, but the test report is welcome nonetheless. The definition of

Re: [PATCH 14/15] mm, dax, pmem: introduce {get|put}_dev_pagemap() for dax-gup

On Fri, Oct 2, 2015 at 2:21 PM, Logan Gunthorpe wrote: > Hi Dan, > > We've been doing some experimenting and testing with this patchset. > Specifically, we are trying to use you're ZONE_DEVICE work to enable > peer to peer PCIe transfers. This is actually working pretty well > (though we're still

Re: [PATCH 14/15] mm, dax, pmem: introduce {get|put}_dev_pagemap() for dax-gup

Hi Dan, We've been doing some experimenting and testing with this patchset. Specifically, we are trying to use you're ZONE_DEVICE work to enable peer to peer PCIe transfers. This is actually working pretty well (though we're still testing and working through some things). However, we've found a

Re: [PATCH 14/15] mm, dax, pmem: introduce {get|put}_dev_pagemap() for dax-gup

On Fri, Oct 2, 2015 at 2:21 PM, Logan Gunthorpe wrote: > Hi Dan, > > We've been doing some experimenting and testing with this patchset. > Specifically, we are trying to use you're ZONE_DEVICE work to enable > peer to peer PCIe transfers. This is actually working pretty well

Re: [PATCH 14/15] mm, dax, pmem: introduce {get|put}_dev_pagemap() for dax-gup

Hi Dan, We've been doing some experimenting and testing with this patchset. Specifically, we are trying to use you're ZONE_DEVICE work to enable peer to peer PCIe transfers. This is actually working pretty well (though we're still testing and working through some things). However, we've found a

Re: [PATCH 14/15] mm, dax, pmem: introduce {get|put}_dev_pagemap() for dax-gup

Hi Dan, Good to know you've already addressed the struct page issue. We'll watch out for an updated patchset to try. On 02/10/15 03:53 PM, Dan Williams wrote: Hmm, I didn't have peer-to-peer PCI-E in mind for this mechanism, but the test report is welcome nonetheless. The definition of

Re: [PATCH 14/15] mm, dax, pmem: introduce {get|put}_dev_pagemap() for dax-gup

On Fri, Oct 2, 2015 at 3:42 PM, Logan Gunthorpe wrote: > > > On 02/10/15 03:53 PM, Dan Williams wrote: >> >> Yes, this location for dev_pagemap will not work. I've since moved it >> to a union with the lru list_head since ZONE_DEVICE pages memory >> should always have an

Re: [PATCH 14/15] mm, dax, pmem: introduce {get|put}_dev_pagemap() for dax-gup

On 02/10/15 03:53 PM, Dan Williams wrote: Yes, this location for dev_pagemap will not work. I've since moved it to a union with the lru list_head since ZONE_DEVICE pages memory should always have an elevated page count and never land on a slab allocator lru. Oh, also, I was actually hoping

[PATCH 14/15] mm, dax, pmem: introduce {get|put}_dev_pagemap() for dax-gup

get_dev_page() enables paths like get_user_pages() to pin a dynamically mapped pfn-range (devm_memremap_pages()) while the resulting struct page objects are in use. Unlike get_page() it may fail if the device is, or is in the process of being, disabled. While the initial lookup of the range may

[PATCH 14/15] mm, dax, pmem: introduce {get|put}_dev_pagemap() for dax-gup

get_dev_page() enables paths like get_user_pages() to pin a dynamically mapped pfn-range (devm_memremap_pages()) while the resulting struct page objects are in use. Unlike get_page() it may fail if the device is, or is in the process of being, disabled. While the initial lookup of the range may