On 31/01/2018 10:01, Vincent Guittot wrote: > Hi Daniel, > > On 23 January 2018 at 16:34, Daniel Lezcano <[email protected]> wrote:
[ ... ] (please trim :) >> + /* >> + * Each cooling device is per package. Each package >> + * has a set of cpus where the physical number is >> + * duplicate in the kernel namespace. We need a way to >> + * address the waitq[] and tsk[] arrays with index >> + * which are not Linux cpu numbered. >> + * >> + * One solution is to use the >> + * topology_core_id(cpu). Other solution is to use the >> + * modulo. >> + * >> + * eg. 2 x cluster - 4 cores. >> + * >> + * Physical numbering -> Linux numbering -> % nr_cpus >> + * >> + * Pkg0 - Cpu0 -> 0 -> 0 >> + * Pkg0 - Cpu1 -> 1 -> 1 >> + * Pkg0 - Cpu2 -> 2 -> 2 >> + * Pkg0 - Cpu3 -> 3 -> 3 >> + * >> + * Pkg1 - Cpu0 -> 4 -> 0 >> + * Pkg1 - Cpu1 -> 5 -> 1 >> + * Pkg1 - Cpu2 -> 6 -> 2 >> + * Pkg1 - Cpu3 -> 7 -> 3 > > > I'm not sure that the assumption above for the CPU numbering is safe. > Can't you use a per cpu structure to point to resources that are per > cpu instead ? so you will not have to rely on CPU ordering Can you elaborate ? I don't get the part with the percpu structure. -- <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
