On 24/02/21 14:30, Vincent Guittot wrote: > Joel reported long preempt and irq off sequence in newidle_balance because > of a large number of CPU cgroups in use and having to be updated. This > patchset moves the update outside newidle_imblance. This enables to early > abort during the updates in case of pending irq as an example. > > Instead of kicking a normal ILB that will wakes up CPU which is already > idle, patch 6 triggers the update of statistics in the idle thread of > the CPU before selecting and entering an idle state. > > Changes on v4: > - Add a dedicated bit for updating blocked load when entering idle. > This simplifies the management of concurrency with kick_ilb. >
I believe that solves the issues vs nohz balance. One last thing for patch 7: mayhaps we could do a tad better to avoid duplicate updates going through a heapful of leaf cfs rqs, see http://lore.kernel.org/r/[email protected] Otherwise, feel free to add to the lot: Reviewed-by: Valentin Schneider <[email protected]>
