Now that we have direct and reliable detection of WC support by the system, use is broadly. The only case we have to worry about is when the WC autodetector cannot run. For this fringe case generally assume that that WC is available, except in the well defined case of no PAT support on x86 which is tested by calling arch_can_pci_mmap_wc(). If WC is wrongly assumed to be available then it causes a small performance hit on paths in userspace that are tuned to the assumption that WC is available. There is no functional loss. It is very unlikely that any platforms exist that lack WC and also care about the micro optimization of WC in the fringe case where autodetection does not work. By removing the fairly bogus CONFIG tests this makes WC work broadly on all arches and all platforms. Link: https://lore.kernel.org/r/20200318100323.46659-1-leon@kernel.org Signed-off-by: Yishai Hadas <yishaih@mellanox.com> Reviewed-by: Michael Guralnik <michaelgur@mellanox.com> Signed-off-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> |
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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 |
README
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.