On Tue, Feb 14, 2012 at 08:30:06PM +0200, Pasi Kärkkäinen wrote: > On Tue, Feb 14, 2012 at 12:06:46AM -0500, Konrad Rzeszutek Wilk wrote: > > > > This "harvester" (I am horrible with names, if you have any suggestions please > > tell me them) collects the information that the cpufreq drivers and the > > ACPI processor code save in the 'struct acpi_processor' and then sends it to > > the hypervisor. > > > > Btw there's a typo in the subject line.. "harester". Duh! > > I'm not very good with names either: collector? passthru? "passthru" sounds better. > > > > The driver can be either an module or compiled in. In either mode the driver > > launches a thread that checks whether an cpufreq driver is registered. If so > > it reads all the 'struct acpi_processor' data for all online CPUs and sends > > it to hypervisor. The driver also register a CPU hotplug component - so if a new > > CPU shows up - it would send the data to the hypervisor for it as well. > > > > I've tested this with success on a variety of Intel and AMD hardware (need > > a patch to the hypervisor to allow the rdmsr to be passed through). The one > > caveat is that dom0_max_vcpus inhibits the driver from reading the vCPUs > > that are not present in dom0. One solution is to boot without dom0_max_vcpus > > and utilize the 'xl vcpu-set' command to offline the vCPUs. Other one that > > Nakajima Jun suggested was to hotplug vCPUS in - so bootup dom0 and hotplug > > the vCPUs in - but I am running in difficulties on how to do this in the hypervisor. > > > > When using this driver do you need to pass any options to Xen hypervisor? > (cpufreq=something) ? No need. You only need that if you want to change the default cpufreq driver from the ondemand to performance (so cpufreq=performance) or want more verbose information: cpufreq=verbose,performance By default the Xen hypervisor will take the cpufreq data in account unless you override that with 'dom0-is-deciding-power-management-and-I-cant-remember-exactly' parameter. > > It might be good to mention something about that in the patch comments. I will include cpufreq=verbose and mention that the effect before and after. And also with xenpm. Thanks! > > -- Pasi > > -- > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
