| Message ID | 1382371508-3843-1-git-send-email-raghavendra.kt@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Oct 21, 2013 at 09:35:08PM +0530, Raghavendra K T wrote: > Since paravirt spinlock optimization are in 3.12 kernel, we have > very good performance benefit for paravirtualized KVM / Xen kernel. > Also we no longer suffer from 5% side effect on native kernel. Yeey! > > Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> > --- > Would like to thank Sander for spotting and suggesting this. > pvspinlock benefit on KVM link: https://lkml.org/lkml/2013/8/6/178 > > Attilio's tests on native kernel impact: > http://blog.xen.org/index.php/2012/05/11/benchmarking-the-new-pv-ticketlock-implementation/ > > arch/x86/Kconfig | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig > index f67e839..4ba9d32 100644 > --- a/arch/x86/Kconfig > +++ b/arch/x86/Kconfig > @@ -638,10 +638,10 @@ config PARAVIRT_SPINLOCKS > 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. > + It has minimal impact on native kernels and gives nice performance > + benefit for paravirtualized KVM / Xen kernels. > > - If you are unsure how to answer this question, answer N. > + If you are unsure how to answer this question, answer Y. > > source "arch/x86/xen/Kconfig" > > -- > 1.7.11.7 > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index f67e839..4ba9d32 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -638,10 +638,10 @@ config PARAVIRT_SPINLOCKS 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. + It has minimal impact on native kernels and gives nice performance + benefit for paravirtualized KVM / Xen kernels. - If you are unsure how to answer this question, answer N. + If you are unsure how to answer this question, answer Y. source "arch/x86/xen/Kconfig"
Since paravirt spinlock optimization are in 3.12 kernel, we have very good performance benefit for paravirtualized KVM / Xen kernel. Also we no longer suffer from 5% side effect on native kernel. Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> --- Would like to thank Sander for spotting and suggesting this. pvspinlock benefit on KVM link: https://lkml.org/lkml/2013/8/6/178 Attilio's tests on native kernel impact: http://blog.xen.org/index.php/2012/05/11/benchmarking-the-new-pv-ticketlock-implementation/ arch/x86/Kconfig | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)