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Mainline Linux tree for various devices, only for fun :)
093ae8f9a8
Currently, the kernel uses [LM]FENCE; RDTSC in the timekeeping code, to guarantee monotonicity of time where the *FENCE is selected based on vendor. Replace that sequence with RDTSCP which is faster or on-par and gives the same guarantees. A microbenchmark on Intel shows that the change is on-par. On AMD, the change is either on-par with the current LFENCE-prefixed RDTSC or slightly better with RDTSCP. The comparison is done with the LFENCE-prefixed RDTSC (and not with the MFENCE-prefixed one, as one would normally expect) because all modern AMD families make LFENCE serializing and thus avoid the heavy MFENCE by effectively enabling X86_FEATURE_LFENCE_RDTSC. Co-developed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: John Stultz <john.stultz@linaro.org> Cc: x86@kernel.org Link: https://lkml.kernel.org/r/20181119184556.11479-1-bp@alien8.de |
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arch | ||
block | ||
certs | ||
crypto | ||
Documentation | ||
drivers | ||
firmware | ||
fs | ||
include | ||
init | ||
ipc | ||
kernel | ||
lib | ||
LICENSES | ||
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 |
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.