This patch implements a fastpath for the preemption timer vmexit. The vmexit can be handled quickly so it can be performed with interrupts off and going back directly to the guest. Testing on SKX Server. cyclictest in guest(w/o mwait exposed, adaptive advance lapic timer is default -1): 5540.5ns -> 4602ns 17% kvm-unit-test/vmexit.flat: w/o avanced timer: tscdeadline_immed: 3028.5 -> 2494.75 17.6% tscdeadline: 5765.7 -> 5285 8.3% w/ adaptive advance timer default -1: tscdeadline_immed: 3123.75 -> 2583 17.3% tscdeadline: 4663.75 -> 4537 2.7% Tested-by: Haiwei Li <lihaiwei@tencent.com> Cc: Haiwei Li <lihaiwei@tencent.com> Signed-off-by: Wanpeng Li <wanpengli@tencent.com> Message-Id: <1588055009-12677-8-git-send-email-wanpengli@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.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.