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| author | Alexey Makhalov | 2016-10-28 09:54:32 +0200 |
|---|---|---|
| committer | Thomas Gleixner | 2016-10-30 08:57:08 +0100 |
| commit | 80e9a4f21fd7ccce7e9b8439986fd028c9946dda (patch) | |
| tree | 4e438295f52bacffc2ca2df175cf68c3b2722e44 /Documentation/kernel-parameters.txt | |
| parent | x86/vmware: Add basic paravirt ops support (diff) | |
| download | kernel-qcow2-linux-80e9a4f21fd7ccce7e9b8439986fd028c9946dda.tar.gz kernel-qcow2-linux-80e9a4f21fd7ccce7e9b8439986fd028c9946dda.tar.xz kernel-qcow2-linux-80e9a4f21fd7ccce7e9b8439986fd028c9946dda.zip | |
x86/vmware: Add paravirt sched clock
The default sched_clock() implementation is native_sched_clock(). It
contains code to handle non constant frequency TSCs, which creates
overhead for systems with constant frequency TSCs.
The vmware hypervisor guarantees a constant frequency TSC, so
native_sched_clock() is not required and slower than a dedicated function
which operates with one time calculated conversion factors.
Calculate the conversion factors at boot time from the tsc frequency and
install an optimized sched_clock() function via paravirt ops.
The paravirtualized clock can be disabled on the kernel command line with
the new 'no-vmw-sched-clock' option.
Signed-off-by: Alexey Makhalov <amakhalov@vmware.com>
Acked-by: Alok N Kataria <akataria@vmware.com>
Cc: linux-doc@vger.kernel.org
Cc: pv-drivers@vmware.com
Cc: corbet@lwn.net
Cc: virtualization@lists.linux-foundation.org
Link: http://lkml.kernel.org/r/20161028075432.90579-4-amakhalov@vmware.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'Documentation/kernel-parameters.txt')
| -rw-r--r-- | Documentation/kernel-parameters.txt | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 37babf91f2cb..b3b2ec00646f 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2754,6 +2754,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. no-kvmapf [X86,KVM] Disable paravirtualized asynchronous page fault handling. + no-vmw-sched-clock + [X86,PV_OPS] Disable paravirtualized VMware scheduler + clock and use the default one. + no-steal-acc [X86,KVM] Disable paravirtualized steal time accounting. steal time is computed, but won't influence scheduler behaviour |