linux-dev/lib/test_hmm.c, branch linus/master

mm: remove the extra ZONE_DEVICE struct page refcount

2022-03-03T17:47:33Z

ZONE_DEVICE struct pages have an extra reference count that complicates the code for put_page() and several places in the kernel that need to check the reference count to see that a page is not being used (gup, compaction, migration, etc.). Clean up the code so the reference count doesn't need to be treated specially for ZONE_DEVICE pages. Note that this excludes the special idle page wakeup for fsdax pages, which still happens at refcount 1. This is a separate issue and will be sorted out later. Given that only fsdax pages require the notifiacation when the refcount hits 1 now, the PAGEMAP_OPS Kconfig symbol can go away and be replaced with a FS_DAX check for this hook in the put_page fastpath. Based on an earlier patch from Ralph Campbell . Link: https://lkml.kernel.org/r/20220210072828.2930359-8-hch@lst.de Signed-off-by: Christoph Hellwig Reviewed-by: Logan Gunthorpe Reviewed-by: Ralph Campbell Reviewed-by: Jason Gunthorpe Reviewed-by: Dan Williams Acked-by: Felix Kuehling Tested-by: "Sierra Guiza, Alejandro (Alex)" Cc: Alex Deucher Cc: Alistair Popple Cc: Ben Skeggs Cc: Chaitanya Kulkarni Cc: Christian Knig Cc: Karol Herbst Cc: Lyude Paul Cc: Miaohe Lin Cc: Muchun Song Cc: "Pan, Xinhui" Signed-off-by: Andrew Morton Signed-off-by: Matthew Wilcox (Oracle)

mm: don't include in

2022-03-03T17:47:33Z

Move the check for the actual pgmap types that need the free at refcount one behavior into the out of line helper, and thus avoid the need to pull memremap.h into mm.h. Link: https://lkml.kernel.org/r/20220210072828.2930359-7-hch@lst.de Signed-off-by: Christoph Hellwig Reviewed-by: Logan Gunthorpe Reviewed-by: Jason Gunthorpe Reviewed-by: Dan Williams Acked-by: Felix Kuehling Tested-by: "Sierra Guiza, Alejandro (Alex)" Cc: Alex Deucher Cc: Alistair Popple Cc: Ben Skeggs Cc: Chaitanya Kulkarni Cc: Karol Herbst Cc: Lyude Paul Cc: Miaohe Lin Cc: Muchun Song Cc: "Pan, Xinhui" Cc: Ralph Campbell Signed-off-by: Andrew Morton Signed-off-by: Matthew Wilcox (Oracle)

mm: remove pointless includes from

2022-03-03T17:47:33Z

hmm.h pulls in the world for no good reason at all. Remove the includes and push a few ones into the users instead. Link: https://lkml.kernel.org/r/20220210072828.2930359-4-hch@lst.de Signed-off-by: Christoph Hellwig Reviewed-by: Logan Gunthorpe Reviewed-by: Jason Gunthorpe Reviewed-by: Chaitanya Kulkarni Reviewed-by: Muchun Song Tested-by: "Sierra Guiza, Alejandro (Alex)" Cc: Alex Deucher Cc: Alistair Popple Cc: Ben Skeggs Cc: Christian Knig Cc: Dan Williams Cc: Felix Kuehling Cc: Karol Herbst Cc: Lyude Paul Cc: Miaohe Lin Cc: "Pan, Xinhui" Cc: Ralph Campbell Signed-off-by: Andrew Morton Signed-off-by: Matthew Wilcox (Oracle)

mm/hmm.c: allow VM_MIXEDMAP to work with hmm_range_fault

2022-01-15T14:30:31Z

hmm_range_fault() can be used instead of get_user_pages() for devices which allow faulting however unlike get_user_pages() it will return an error when used on a VM_MIXEDMAP range. To make hmm_range_fault() more closely match get_user_pages() remove this restriction. This requires dealing with the !ARCH_HAS_PTE_SPECIAL case in hmm_vma_handle_pte(). Rather than replicating the logic of vm_normal_page() call it directly and do a check for the zero pfn similar to what get_user_pages() currently does. Also add a test to hmm selftest to verify functionality. Link: https://lkml.kernel.org/r/20211104012001.2555676-1-apopple@nvidia.com Fixes: da4c3c735ea4 ("mm/hmm/mirror: helper to snapshot CPU page table") Signed-off-by: Alistair Popple Reviewed-by: Jason Gunthorpe Cc: Jerome Glisse Cc: John Hubbard Cc: Zi Yan Cc: Ralph Campbell Cc: Felix Kuehling Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm/migrate.c: remove MIGRATE_PFN_LOCKED

2021-11-11T17:34:35Z

MIGRATE_PFN_LOCKED is used to indicate to migrate_vma_prepare() that a source page was already locked during migrate_vma_collect(). If it wasn't then the a second attempt is made to lock the page. However if the first attempt failed it's unlikely a second attempt will succeed, and the retry adds complexity. So clean this up by removing the retry and MIGRATE_PFN_LOCKED flag. Destination pages are also meant to have the MIGRATE_PFN_LOCKED flag set, but nothing actually checks that. Link: https://lkml.kernel.org/r/20211025041608.289017-1-apopple@nvidia.com Signed-off-by: Alistair Popple Reviewed-by: Ralph Campbell Acked-by: Felix Kuehling Cc: Alex Deucher Cc: Jerome Glisse Cc: John Hubbard Cc: Zi Yan Cc: Christoph Hellwig Cc: Ben Skeggs Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

lib/test_hmm: remove set but unused page variable

2021-07-15T17:13:49Z

The HMM selftests use atomic_check_access() to check atomic access to a page has been revoked. It doesn't matter if the page mapping has been removed from the mirrored page tables as that also implies atomic access has been revoked. Therefore remove the unused page variable to fix this compiler warning: lib/test_hmm.c:631:16: warning: variable `page' set but not used [-Wunused-but-set-variable] Link: https://lkml.kernel.org/r/20210706025603.4059-1-apopple@nvidia.com Fixes: b659baea7546 ("mm: selftests for exclusive device memory") Signed-off-by: Alistair Popple Reported-by: Hulk Robot Reported-by: kernel test robot Reported-by: Yang Yingliang Acked-by: Souptick Joarder Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: selftests for exclusive device memory

2021-07-01T18:06:03Z

Adds some selftests for exclusive device memory. Link: https://lkml.kernel.org/r/20210616105937.23201-9-apopple@nvidia.com Signed-off-by: Alistair Popple Acked-by: Jason Gunthorpe Tested-by: Ralph Campbell Reviewed-by: Ralph Campbell Cc: Ben Skeggs Cc: Christoph Hellwig Cc: Hugh Dickins Cc: John Hubbard Cc: "Matthew Wilcox (Oracle)" Cc: Peter Xu Cc: Shakeel Butt Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: rename migrate_pgmap_owner

2021-07-01T18:06:03Z

MMU notifier ranges have a migrate_pgmap_owner field which is used by drivers to store a pointer. This is subsequently used by the driver callback to filter MMU_NOTIFY_MIGRATE events. Other notifier event types can also benefit from this filtering, so rename the 'migrate_pgmap_owner' field to 'owner' and create a new notifier initialisation function to initialise this field. Link: https://lkml.kernel.org/r/20210616105937.23201-6-apopple@nvidia.com Signed-off-by: Alistair Popple Suggested-by: Peter Xu Reviewed-by: Peter Xu Cc: Ben Skeggs Cc: Christoph Hellwig Cc: Hugh Dickins Cc: Jason Gunthorpe Cc: John Hubbard Cc: "Matthew Wilcox (Oracle)" Cc: Ralph Campbell Cc: Shakeel Butt Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

lib/test_hmm: use vma_lookup() in dmirror_migrate()

2021-06-29T17:53:52Z

Use vma_lookup() to find the VMA at a specific address. As vma_lookup() will return NULL if the address is not within any VMA, the start address no longer needs to be validated. Link: https://lkml.kernel.org/r/20210521174745.2219620-18-Liam.Howlett@Oracle.com Signed-off-by: Liam R. Howlett Reviewed-by: Laurent Dufour Acked-by: David Hildenbrand Acked-by: Davidlohr Bueso Cc: Geert Uytterhoeven Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

lib/test_hmm.c: fix an error code in dmirror_allocate_chunk()

2020-10-16T18:11:20Z

This is supposed to return false on failure, not a negative error code. Fixes: 170e38548b81 ("mm/hmm/test: use after free in dmirror_allocate_chunk()") Signed-off-by: Dan Carpenter Signed-off-by: Andrew Morton Reviewed-by: Ralph Campbell Cc: Jerome Glisse Cc: Stephen Rothwell Cc: Jason Gunthorpe Cc: Dan Williams Link: https://lkml.kernel.org/r/20201010200812.GA1886610@mwanda Signed-off-by: Linus Torvalds