On 10/04/2012 04:14 PM, Peter De Schrijver wrote: > On Tue, Sep 25, 2012 at 12:43:54AM +0200, Daniel Lezcano wrote: >> With the tegra3 and the big.LITTLE [1] new architectures, several cpus >> with different characteristics (latencies and states) can co-exists on the >> system. >> >> The cpuidle framework has the limitation of handling only identical cpus. >> >> This patch removes this limitation by introducing the multiple driver support >> for cpuidle. >> >> This option is configurable at compile time and should be enabled for the >> architectures mentioned above. So there is no impact for the other platforms >> if the option is disabled. The option defaults to 'n'. Note the multiple drivers >> support is also compatible with the existing drivers, even if just one driver is >> needed, all the cpu will be tied to this driver using an extra small chunk of >> processor memory. >> >> The multiple driver support use a per-cpu driver pointer instead of a global >> variable and the accessor to this variable are done from a cpu context. >> >> In order to keep the compatibility with the existing drivers, the function >> 'cpuidle_register_driver' and 'cpuidle_unregister_driver' will register >> the specified driver for all the cpus. >> >> The sysfs output for the 'current_driver' is changed when this option is >> set by giving the drivers per cpu. >> >> eg. >> cpu0: acpi_idle >> cpu1: acpi_idle >> > > Is this allowed? I thought sysfs files can output only 1 line of data? Ah yeah :) Does it make sense to put the following files: /sys/devices/system/cpu/cpu0/cpuidle/driver => acpi_idle /sys/devices/system/cpu/cpu1/cpuidle/driver => acpi_idle and the content of the file: /sys/devices/system/cpu/cpuidle/current_driver will show the driver associated with current cpu ? -- <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook | <http://twitter.com/#!/linaroorg> Twitter | <http://www.linaro.org/linaro-blog/> Blog -- 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
