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Ryan Roberts
3425cec42c
set_ptes() sets a physically contiguous block of memory (which all belongs to the same folio) to a contiguous block of ptes. The arm64 implementation of this previously just looped, operating on each individual pte. But the __sync_icache_dcache() and mte_sync_tags() operations can both be hoisted out of the loop so that they are performed once for the contiguous set of pages (which may be less than the whole folio). This should result in minor performance gains. __sync_icache_dcache() already acts on the whole folio, and sets a flag in the folio so that it skips duplicate calls. But by hoisting the call, all the pte testing is done only once. mte_sync_tags() operates on each individual page with its own loop. But by passing the number of pages explicitly, we can rely solely on its loop and do the checks only once. This approach also makes it robust for the future, rather than assuming if a head page of a compound page is being mapped, then the whole compound page is being mapped, instead we explicitly know how many pages are being mapped. The old assumption may not continue to hold once the "anonymous large folios" feature is merged. Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Reviewed-by: Steven Price <steven.price@arm.com> Link: https://lore.kernel.org/r/20231005140730.2191134-1-ryan.roberts@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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 Restructured Text 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.