On 02/06/2017 11:20, Sudeep Holla wrote: > > > On 01/06/17 12:39, Daniel Lezcano wrote: >> Some hardware have clusters with different idle states. The current code does >> not support this and fails as it expects all the idle states to be identical. >> >> Because of this, the Mediatek mtk8173 had to create the same idle state for a >> big.Little system and now the Hisilicon 960 is facing the same situation. >> >> Solve this by simply assuming the multiple driver will be needed for all the >> platforms using the ARM generic cpuidle driver which makes sense because of >> the >> different topologies we can support with a single kernel for ARM32 or ARM64. >> >> Every CPU has its own driver, so every single CPU can specify in the DT the >> idle states. >> >> This simple approach allows to support the future dynamIQ system, current SMP >> and HMP. >> >> It is unoptimal from a memory point of view for a system with a large number >> of >> CPUs but nowadays there is no such system with a cpuidle driver on ARM. >> > > While I agree this may be simple solution, but just not necessary for > systems with symmetric idle states especially one with large number of > CPUs. I don't like to see 96 CPU Idle driver on say ThunderX. So we > *must* have some basic distinction done here. > > IMO, we can't punish a large SMP systems just because they don't have > asymmetric idle states.
Can you point me in the upstream kernel a DTS with 96 cpus and using the cpuidle-arm driver ? -- <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
