On Tuesday, January 17, 2012 12:06:19 PM Len Brown wrote: > On 11/17/2011 05:36 PM, Thomas Renninger wrote: > > > Function split up, should have no functional change > > benefit? The idea was: Provide a basic init func which can be called in ACPI CPU hotplug context safely before the CPU is brought up the first time and: struct cpuinfo_x86 (like CPU features) of the new CPU is not set up yet. Do the idle/throttling/... init later when the physically hotplugged CPU is onlined the first time (and therefore got fully booted and initialized). While I had this working, I now have a better idea which does not need this split: When the ACPI CPU hotplug event is caught, fill up cpu_data(new_cpu) data as much and good as possilbe, do something like: memcpy(&cpu_data(new_cpu), &boot_cpu_data, sizeof(struct cpuinfo_x86); and adjust: phys_proc_id cpu_core_id apicid initial_apicid ... Then cpuidle (and throttling,...) can be initialized without the need of booting up the CPU first. Not sure whether the memcpy would succeed if the CPU is not (and never was) online. From what I saw it should work, but I am not sure. Tejun: Do you know that? Another option would be what Bjorn Helgaas suggested: Immediately online the CPU, but this would heavily interfere with the current (generic code) approach, but after some thinking and looking at the code: this shouldn't bring much benefit. Thomas -- 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
