Re: [PATCH 1/8] cgroup: killcgroup_subsys->__DEPRECATED_clear_css_refs

[Michal Hocko]

On Wed 31-10-12 13:24:00, Tejun Heo wrote:
[...]
> local_irq_save/restore() from cgroup_clear_css_refs() are replaced
> with local_irq_disable/enable() for simplicity.  This is safe as
> cgroup_rmdir() is always called with IRQ enabled.  Note that this IRQ
> switching is necessary to ensure that css_tryget() isn't called from
> IRQ context on the same CPU while lower context is between CSS
> deactivation and setting CSS_REMOVED as css_tryget() would hang
> forever in such cases waiting for CSS to be re-activated or
> CSS_REMOVED set.  This will go away soon.

Much better. Thanks a lot!
-- 
Michal Hocko
SUSE Labs
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