9b60472205
In set_pte_at(), we read the old pte value so that it can be passed into checks for racy hw updates. These checks are only performed for CONFIG_DEBUG_VM, and the value is not used otherwise. Since we read the pte value with READ_ONCE(), the compiler cannot elide the redundant read for !CONFIG_DEBUG_VM kernels. Let's ameliorate matters by moving the read and the checks into a helper, __check_racy_pte_update(), which only performs the read when the value will be used. This also allows us to reformat the conditions for clarity. Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Mark Rutland <mark.rutland@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.