On Fri, Oct 14, 2016 at 11:53:18AM +1100, Suraj Jitindar Singh wrote: > This patch series makes some updates and bug fixes to the powerpc kvm-hv > halt polling code. > > The first two patches are concerned with exporting the generic kvm module > parameter variables and accessing these from the powerpc specific code. > > The third patch fixes a bug where changing the global max halt polling > interval module parameter can sometimes have no effect. > > The fourth patch decreases the default global max halt polling interval > to something more sensible. > > The fifth patch contains generic fixups with no functional effect. > > The last patch adds halt polling documentation. > > Suraj Jitindar Singh (6): > kvm: export kvm module parameter variables > powerpc/kvm: Use generic kvm module parameters in kvm-hv > powerpc/kvm: Add check for module parameter halt_poll_ns > powerpc/kvm: Decrease the powerpc default halt poll max value > powerpc/kvm: Comment style and print format fixups > doc/kvm: Add halt polling documentation > > Documentation/virtual/kvm/00-INDEX | 2 + > Documentation/virtual/kvm/halt-polling.txt | 127 +++++++++++++++++++++++++++++ > arch/powerpc/include/asm/kvm_host.h | 2 +- > arch/powerpc/kvm/book3s_hv.c | 33 ++------ > arch/powerpc/kvm/trace_hv.h | 2 +- > include/linux/kvm_host.h | 4 + > virt/kvm/kvm_main.c | 9 +- > 7 files changed, 149 insertions(+), 30 deletions(-) > create mode 100644 Documentation/virtual/kvm/halt-polling.txt > > -- > 2.5.5 Hi Suraj, I've given this set a quick test and it seems to work fine. I used a repetitive wakeup, using a nanosleep loop in guest userspace (with real time prio), and I was able to cause halt polling to switch on and off as I adjusted halt_poll_ns. I think the new default value is much better: halt polling started (e.g. CPU utilization rose to 100%) once CPU utilization had already risen to about 75%. Cheers, Sam. Tested-by: Sam Bobroff <sam.bobroff@xxxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html