Hi Raghavendra,
Since the ticketlock series have landed in this mergewindow (thanks :-) ) the
help accompanying the Kconfig entry doesn't seem to reflect the current state
well.
- Wasn't the whole purpose of the ticketlock series to mitigate this 5%
performance hit to something
far less, so distro kernels could enable this for their normal kernels ?
I don't have the exact performance figures though.
- Perhaps the suggestion to enable this for supported hypervisors (Xen and KVM
?) could be added ?
--
Sander
CONFIG_PARAVIRT_SPINLOCKS:
Paravirtualized spinlocks allow a pvops backend to replace the
spinlock implementation with something virtualization-friendly
(for example, block the virtual CPU rather than spinning).
Unfortunately the downside is an up to 5% performance hit on
native kernels, with various workloads.
If you are unsure how to answer this question, answer N.
Symbol: PARAVIRT_SPINLOCKS [=y]
Type : boolean
Prompt: Paravirtualization layer for spinlocks
Location:
-> Processor type and features
-> Linux guest support (HYPERVISOR_GUEST [=y])
-> Enable paravirtualization code (PARAVIRT [=y])
Defined at arch/x86/Kconfig:632
Depends on: HYPERVISOR_GUEST [=y] && PARAVIRT [=y] && SMP [=y]
Selects: UNINLINE_SPIN_UNLOCK [=y]
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