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author | Alistair Popple <apopple@nvidia.com> | 2021-11-10 20:32:40 -0800 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-11-11 09:34:35 -0800 |
commit | ab09243aa95a72bac5c71e852773de34116f8d0f (patch) | |
tree | 825f51109c310ac95b1bf5278394badbec8fd6dc /lib | |
parent | 0ef024621417fa3fcdeb2c3320f90ee34e18a5d9 (diff) | |
download | lwn-ab09243aa95a72bac5c71e852773de34116f8d0f.tar.gz lwn-ab09243aa95a72bac5c71e852773de34116f8d0f.zip |
mm/migrate.c: remove MIGRATE_PFN_LOCKED
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 <apopple@nvidia.com>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Acked-by: Felix Kuehling <Felix.Kuehling@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib')
-rw-r--r-- | lib/test_hmm.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/lib/test_hmm.c b/lib/test_hmm.c index c259842f6d44..e2ce8f9b7605 100644 --- a/lib/test_hmm.c +++ b/lib/test_hmm.c @@ -613,8 +613,7 @@ static void dmirror_migrate_alloc_and_copy(struct migrate_vma *args, */ rpage->zone_device_data = dmirror; - *dst = migrate_pfn(page_to_pfn(dpage)) | - MIGRATE_PFN_LOCKED; + *dst = migrate_pfn(page_to_pfn(dpage)); if ((*src & MIGRATE_PFN_WRITE) || (!spage && args->vma->vm_flags & VM_WRITE)) *dst |= MIGRATE_PFN_WRITE; @@ -1137,7 +1136,7 @@ static vm_fault_t dmirror_devmem_fault_alloc_and_copy(struct migrate_vma *args, lock_page(dpage); xa_erase(&dmirror->pt, addr >> PAGE_SHIFT); copy_highpage(dpage, spage); - *dst = migrate_pfn(page_to_pfn(dpage)) | MIGRATE_PFN_LOCKED; + *dst = migrate_pfn(page_to_pfn(dpage)); if (*src & MIGRATE_PFN_WRITE) *dst |= MIGRATE_PFN_WRITE; } |