On Fri, 30 Nov 2007 14:06:55 -0800 "Pallipadi, Venkatesh" <venkatesh.pallipadi@xxxxxxxxx> wrote: Please dont go off-list like this. I put Mark's original mailing list cc's back. > > I will have to Nack this. The reason max_cstate was initentionally > removed due to couple of reasons: It broke userspace without any warning or migration period, afaict. > 1) All in kernel users of max_cstate should rather be using > pm_qos/latency interfaces. All such max_cstate usages must already be > migrated. That code isn't merged. > 2) Supporting max_cstate as a dynamic parameter cleanly is no longer > possible in acpi/processor_idle.c as the C-state policy has moved to > cpuidle instead. It can be done if it is needed. But, just below patch > will not really work with cpuidle. > > Selecting max_cstate at boot time as a debug option still works without > this patch. > > So, just this patch will not get back the functionality with cpuidle. > Infact changing it at run time will have no effect. Question however is: > Is there a real need to revive this parameter so that user can change > max_cstate at run time? It is not known whether Mark is actually writing to this thing. Perhaps read-only permissions would be a suitable fix? - 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
