| From | Valentin Schneider <> | Subject | Re: [PATCH 0/7 v4] move update blocked load outside newidle_balance | Date | Wed, 24 Feb 2021 18:46:23 +0000 |
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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/jhj4kiht7oh.mognet@arm.com
Otherwise, feel free to add to the lot:
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
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