On Fri, Jun 27, 2008 at 05:13:24PM +0100, Richard Hughes wrote: > At the moment we set: > > # CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE is not set > CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE=y > # CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND is not set > # CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE is not set > CONFIG_CPU_FREQ_GOV_PERFORMANCE=y > CONFIG_CPU_FREQ_GOV_POWERSAVE=m > CONFIG_CPU_FREQ_GOV_USERSPACE=y > CONFIG_CPU_FREQ_GOV_ONDEMAND=m > CONFIG_CPU_FREQ_GOV_CONSERVATIVE=m > > This is not ideal from a power-saving point of view. > > In an ideal world we would: > > * remove CONFIG_CPU_FREQ_GOV_CONSERVATIVE -- ondemand does a better job > on all workloads > * remove CONFIG_CPU_FREQ_GOV_USERSPACE -- we have nothing in userspace > that needs this sort of control, and if we did, the latency would be > horrible needed for the cpuspeed governor > * remove CONFIG_CPU_FREQ_GOV_POWERSAVE -- ondemand automatically > throttles down to lowest, and is just a hardcoded state > * compile into the kernel CONFIG_CPU_FREQ_GOV_ONDEMAND -- we really > want to be running this on all systems that support it > * set ONDEMAND or PERFORMANCE to default as USERSPACE is just changed > to something else by cpuspeed. You really don't want to be using > USERSPACE at all. Not all CPUs are capable of running ondemand because of the latency they incur during transitions. > Matthew Garrett and I are working on a latency profile for power > management, and having all these modules potentially loaded is bad. I don't follow this. Can you show whatever numbers you have that you're basing this on ? Dave -- http://www.codemonkey.org.uk _______________________________________________ Fedora-kernel-list mailing list Fedora-kernel-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/fedora-kernel-list
