Commits
Alexey Makhalov committed 80e9a4f21fd
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>