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.
Christophe Leroy
authored
flush_dcache_icache_hugepage() is a static function, with only one caller. That caller calls it when PageCompound() is true, so bugging on !PageCompound() is useless if we can trust the compiler a little. Remove the BUG_ON(!PageCompound()). The number of elements of a page won't change over time, but GCC doesn't know about it, so it gets the value at every iteration. To avoid that, call compound_nr() outside the loop and save it in a local variable. Whether the page is a HIGHMEM page or not doesn't change over time. But GCC doesn't know it so it does the test on every iteration. Do the test outside the loop. When the page is not a HIGHMEM page, page_address() will fallback on lowmem_page_address(), so call lowmem_page_address() directly and don't suffer the call to page_address() on every iteration. Signed-off-by:Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by:
Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/ab03712b70105fccfceef095aa03007de9295a40.1617895813.git.christophe.leroy@csgroup.eu
| Name | Last commit | Last update |
|---|---|---|
| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README |