8fab6a9d72
Since commit b03fc1173c0c ("bitops: let optimize out non-atomic bitops
on compile-time constants"), the non-atomic bitops are macros which can
be expanded by the compilers into compile-time expressions, which will
result in better optimized object code. Unfortunately, turned out that
passing `volatile` to those macros discards any possibility of
optimization, as the compilers then don't even try to look whether
the passed bitmap is known at compilation time. In addition to that,
the mentioned linkmode helpers are marked with `inline`, not
`__always_inline`, meaning that it's not guaranteed some compiler won't
uninline them for no reason, which will also effectively prevent them
from being optimized (it's a well-known thing the compilers sometimes
uninline `2 + 2`).
Convert linkmode_*_bit() from inlines to macros. Their calling
convention are 1:1 with the corresponding bitops, so that it's not even
needed to enumerate and map the arguments, only the names. No changes in
vmlinux' object code (compiled by LLVM for x86_64) whatsoever, but that
doesn't necessarily means the change is meaningless.
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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.