kernel/linux.git/include/linux/memremap.h, branch v6.6.132

mm/memremap: Replace zero-length array with DECLARE_FLEX_ARRAY() helper

2023-01-05T22:15:26+00:00

Zero-length arrays are deprecated and we are moving towards adopting C99 flexible-array members, instead. So, replace zero-length array declaration in struct dev_pagemap with the new DECLARE_FLEX_ARRAY() helper macro. This helper allows for a flexible-array member in a union. Also, this addresses multiple warnings reported when building with Clang-15 and -Wzero-length-array. Link: https://github.com/KSPP/linux/issues/193 Link: https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html Reviewed-by: Kees Cook Signed-off-by: Gustavo A. R. Silva

mm: free device private pages have zero refcount

2022-10-13T01:51:49+00:00

Since 27674ef6c73f ("mm: remove the extra ZONE_DEVICE struct page refcount") device private pages have no longer had an extra reference count when the page is in use. However before handing them back to the owning device driver we add an extra reference count such that free pages have a reference count of one. This makes it difficult to tell if a page is free or not because both free and in use pages will have a non-zero refcount. Instead we should return pages to the drivers page allocator with a zero reference count. Kernel code can then safely use kernel functions such as get_page_unless_zero(). Link: https://lkml.kernel.org/r/cf70cf6f8c0bdb8aaebdbfb0d790aea4c683c3c6.1664366292.git-series.apopple@nvidia.com Signed-off-by: Alistair Popple Acked-by: Felix Kuehling Cc: Jason Gunthorpe Cc: Michael Ellerman Cc: Alex Deucher Cc: Christian König Cc: Ben Skeggs Cc: Lyude Paul Cc: Ralph Campbell Cc: Alex Sierra Cc: John Hubbard Cc: Dan Williams Cc: David Hildenbrand Cc: "Huang, Ying" Cc: Matthew Wilcox Cc: Yang Shi Cc: Zi Yan Signed-off-by: Andrew Morton

mm/memory-failure: fix detection of memory_failure() handlers

2022-09-11T23:22:29+00:00

Some pagemap types, like MEMORY_DEVICE_GENERIC (device-dax) do not even have pagemap ops which results in crash signatures like this: BUG: kernel NULL pointer dereference, address: 0000000000000010 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 8000000205073067 P4D 8000000205073067 PUD 2062b3067 PMD 0 Oops: 0000 [#1] PREEMPT SMP PTI CPU: 22 PID: 4535 Comm: device-dax Tainted: G OE N 6.0.0-rc2+ #59 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:memory_failure+0x667/0xba0 [..] Call Trace: ? _printk+0x58/0x73 do_madvise.part.0.cold+0xaf/0xc5 Check for ops before checking if the ops have a memory_failure() handler. Link: https://lkml.kernel.org/r/166153428781.2758201.1990616683438224741.stgit@dwillia2-xfh.jf.intel.com Fixes: 33a8f7f2b3a3 ("pagemap,pmem: introduce ->memory_failure()") Signed-off-by: Dan Williams Acked-by: Naoya Horiguchi Reviewed-by: Miaohe Lin Reviewed-by: Christoph Hellwig Cc: Shiyang Ruan Cc: Darrick J. Wong Cc: Al Viro Cc: Dave Chinner Cc: Goldwyn Rodrigues Cc: Jane Chu Cc: Matthew Wilcox Cc: Ritesh Harjani Signed-off-by: Andrew Morton

pagemap,pmem: introduce ->memory_failure()

2022-07-18T00:14:30+00:00

When memory-failure occurs, we call this function which is implemented by each kind of devices. For the fsdax case, pmem device driver implements it. Pmem device driver will find out the filesystem in which the corrupted page located in. With dax_holder notify support, we are able to notify the memory failure from pmem driver to upper layers. If there is something not support in the notify routine, memory_failure will fall back to the generic hanlder. Link: https://lkml.kernel.org/r/20220603053738.1218681-4-ruansy.fnst@fujitsu.com Signed-off-by: Shiyang Ruan Reviewed-by: Christoph Hellwig Reviewed-by: Dan Williams Reviewed-by: Darrick J. Wong Reviewed-by: Naoya Horiguchi Cc: Al Viro Cc: Dan Williams Cc: Dave Chinner Cc: Goldwyn Rodrigues Cc: Goldwyn Rodrigues Cc: Jane Chu Cc: Matthew Wilcox Cc: Miaohe Lin Cc: Ritesh Harjani Signed-off-by: Andrew Morton

mm: add zone device coherent type memory support

2022-07-18T00:14:27+00:00

Device memory that is cache coherent from device and CPU point of view. This is used on platforms that have an advanced system bus (like CAPI or CXL). Any page of a process can be migrated to such memory. However, no one should be allowed to pin such memory so that it can always be evicted. [hch@lst.de: rebased ontop of the refcount changes, remove is_dev_private_or_coherent_page] Link: https://lkml.kernel.org/r/20220715150521.18165-4-alex.sierra@amd.com Signed-off-by: Alex Sierra Signed-off-by: Christoph Hellwig Acked-by: Felix Kuehling Reviewed-by: Alistair Popple Acked-by: David Hildenbrand Cc: Jason Gunthorpe Cc: Jerome Glisse Cc: Matthew Wilcox Cc: Ralph Campbell Signed-off-by: Andrew Morton

mm: move page zone helpers from mm.h to mmzone.h

2022-07-18T00:14:27+00:00

It makes more sense to have these helpers in zone specific header file, rather than the generic mm.h Link: https://lkml.kernel.org/r/20220715150521.18165-3-alex.sierra@amd.com Signed-off-by: Alex Sierra Cc: Alistair Popple Cc: Christoph Hellwig Cc: David Hildenbrand Cc: Felix Kuehling Cc: Jason Gunthorpe Cc: Jerome Glisse Cc: Matthew Wilcox Cc: Ralph Campbell Signed-off-by: Andrew Morton

docs: rename Documentation/vm to Documentation/mm

2022-06-27T19:52:53+00:00

so it will be consistent with code mm directory and with Documentation/admin-guide/mm and won't be confused with virtual machines. Signed-off-by: Mike Rapoport Suggested-by: Matthew Wilcox Tested-by: Ira Weiny Acked-by: Jonathan Corbet Acked-by: Wu XiangCheng

mm: Add three folio wrappers

2022-03-21T16:57:38+00:00

folio_is_zone_device() is equivalent to is_zone_device_page(), folio_is_device_private() is equivalent to is_device_private_page(), and folio_is_pinnable() is equivalent to is_pinnable_page(). All of these tests return the same result for every page in the folio, so we can just pass the head page of the folio to the page variant of the function. Signed-off-by: Matthew Wilcox (Oracle)

mm: remove the extra ZONE_DEVICE struct page refcount

2022-03-03T17:47:33+00:00

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

2022-03-03T17:47:33+00:00

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)