diff options
| author | Alexey Makhalov <amakhalov@vmware.com> | 2016-10-28 00:54:32 -0700 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2016-10-30 08:57:08 +0100 |
| commit | 80e9a4f21fd7ccce7e9b8439986fd028c9946dda (patch) | |
| tree | 4e438295f52bacffc2ca2df175cf68c3b2722e44 /kernel/exit.c | |
| parent | 91d1e54ebd1615d216b7f57324a5e69166a344e0 (diff) | |
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 'kernel/exit.c')
0 files changed, 0 insertions, 0 deletions