On 08/06/2018 06:48, Viresh Kumar wrote: > On 07-06-18, 16:11, Daniel Lezcano wrote: >>>> I'm wondering if we can have a CPU hotplugged right after the >>>> 'put_online_cpus', resulting in the 'should park' flag set and then the >>>> thread goes in the kthread_parkme instead of jumping back the idle >>>> injection function and decrease the count, leading up to the timer not >>>> being set again. >>> >>> True. That looks like a valid problem to me as well. >>> >>> What about starting the hrtimer right from this routine itself, after taking >>> into account running-time, idle-time, delay, etc ? That would get rid of the >>> count stuff, this get_online_cpus(), etc. >>> >>> Even if we restart the next play-idle cycle a bit early or with some delay, >>> sky >>> wouldn't fall :) >> >> We won't be able to call completion() in this case. > > I was just having a look at smpboot.h and saw the park/unpark callbacks. I > think > you can very much use them to align things with CPU hotplug.
Hmm, perhaps. I will have a look at it. -- <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
