0d10fe7591
Use try_cmpxchg64 instead of cmpxchg64 (*ptr, old, new) != old in alloc_pte and free_clear_pte. cmpxchg returns success in ZF flag, so this change saves a compare after cmpxchg (and related move instruction in front of cmpxchg). Also, remove racy explicit assignment to pteval when cmpxchg fails, this is what try_cmpxchg does implicitly from *pte in an atomic way. Signed-off-by: Uros Bizjak <ubizjak@gmail.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20220525145416.10816-1-ubizjak@gmail.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
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.