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8c6ff7f181
We already are registering private-anon VMAs with khugepaged during fault
time, in do_huge_pmd_anonymous_page(). Commit "register suitable readonly
file vmas for khugepaged" moved the khugepaged registration logic from
shmem_mmap to the generic mmap path.
The userspace-visible effect should be this: khugepaged will unnecessarily
scan mm's which haven't yet faulted in. Note that it won't actually
collapse because all PTEs are none.
Now that I think about it, the mm is going to have a file VMA anyways
during fork+exec, so the mm already gets registered during mmap due to the
non-anon case (I *think*), so at least one of either the mmap registration
or fault-time registration is redundant.
Make this logic specific for non-anon mappings.
Link: https://lkml.kernel.org/r/20250306063037.16299-1-dev.jain@arm.com
Fixes: 613bec092f ("mm: mmap: register suitable readonly file vmas for khugepaged")
Signed-off-by: Dev Jain <dev.jain@arm.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcow (Oracle) <willy@infradead.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yang Shi <yang@os.amperecomputing.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Linux kernel
============
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In order to build the documentation, use ``make htmldocs`` or
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There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.