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Patch series "Optimizations for khugepaged", v4. If the underlying folio mapped by the ptes is large, we can process those ptes in a batch using folio_pte_batch(). For arm64 specifically, this results in a 16x reduction in the number of ptep_get() calls, since on a contig block, ptep_get() on arm64 will iterate through all 16 entries to collect a/d bits. Next, ptep_clear() will cause a TLBI for every contig block in the range via contpte_try_unfold(). Instead, use clear_ptes() to only do the TLBI at the first and last contig block of the range. For split folios, there will be no pte batching; the batch size returned by folio_pte_batch() will be 1. For pagetable split folios, the ptes will still point to the same large folio; for arm64, this results in the optimization described above, and for other arches, a minor improvement is expected due to a reduction in the number of function calls and batching atomic operations. This patch (of 3): Let's add variants to be used where "full" does not apply -- which will be the majority of cases in the future. "full" really only applies if we are about to tear down a full MM. Use get_and_clear_ptes() in existing code, clear_ptes() users will be added next. Link: https://lkml.kernel.org/r/20250724052301.23844-2-dev.jain@arm.com Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Dev Jain <dev.jain@arm.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Barry Song <baohua@kernel.org> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
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.