Re: [RFC PATCH 0/7] Make rstat flushing IRQ and sleep friendly

From: Shakeel Butt
Date: Thu Mar 23 2023 - 00:10:41 EST


On Wed, Mar 22, 2023 at 9:00 PM Yosry Ahmed <yosryahmed@xxxxxxxxxx> wrote:
>
> Currently, if rstat flushing is invoked using the irqsafe variant
> cgroup_rstat_flush_irqsafe(), we keep interrupts disabled and do not
> sleep for the entire flush operation, which is O(# cpus * # cgroups).
> This can be rather dangerous.
>
> Not all contexts that use cgroup_rstat_flush_irqsafe() actually cannot
> sleep, and among those that cannot sleep, not all contexts require
> interrupts to be disabled.

Too many negations in the above sentence is making it very confusing.