diff options
| author |   Christoph Hellwig <hch@lst.de> | 2022-02-16 15:31:36 +1100 |
|---|---|---|
| committer |   Matthew Wilcox (Oracle) <willy@infradead.org> | 2022-03-03 12:47:33 -0500 |
| commit | 27674ef6c73f0c9096a9827dc5d6ba9fc7808422 (patch) | |
| tree | 1f57be13e778f35d1ca21902eb4c355d5476b44c /mm/Kconfig | |
| parent | mm: don't include <linux/memremap.h> in <linux/mm.h> (diff) | |
| download | linux-dev-27674ef6c73f0c9096a9827dc5d6ba9fc7808422.tar.xz linux-dev-27674ef6c73f0c9096a9827dc5d6ba9fc7808422.zip | |
mm: remove the extra ZONE_DEVICE struct page refcount
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 <rcampbell@nvidia.com>.
Link: https://lkml.kernel.org/r/20220210072828.2930359-8-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Felix Kuehling <Felix.Kuehling@amd.com>
Tested-by: "Sierra Guiza, Alejandro (Alex)" <alex.sierra@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Chaitanya Kulkarni <kch@nvidia.com>
Cc: Christian Knig <christian.koenig@amd.com>
Cc: Karol Herbst <kherbst@redhat.com>
Cc: Lyude Paul <lyude@redhat.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Diffstat (limited to 'mm/Kconfig')
| -rw-r--r-- | mm/Kconfig | 4 |
1 files changed, 0 insertions, 4 deletions
diff --git a/mm/Kconfig b/mm/Kconfig index 3326ee3903f3..a1901ae6d062 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -776,9 +776,6 @@ config ZONE_DEVICE If FS_DAX is enabled, then say Y. -config DEV_PAGEMAP_OPS - bool - # # Helpers to mirror range of the CPU page tables of a process into device page # tables. @@ -790,7 +787,6 @@ config HMM_MIRROR config DEVICE_PRIVATE bool "Unaddressable device memory (GPU memory, ...)" depends on ZONE_DEVICE - select DEV_PAGEMAP_OPS help Allows creation of struct pages to represent unaddressable device |