Re: [PATCH V2] blk-cgroup: prevent rcu_sched detected stalls warnings while iterating blkgs

[Tejun Heo]

On Wed, Jul 07, 2021 at 09:56:49AM +0800, Yu Kuai wrote:
> We run a test that create millions of cgroups and blkgs, and then trigger
> blkg_destroy_all(). blkg_destroy_all() will hold spin lock for a long
> time in such situation. Thus release the lock when a batch of blkgs are
> destroyed.
> 
> blkcg_activate_policy() and blkcg_deactivate_policy() might have the
> same problem, however, as they are basically only called from module
> init/exit paths, let's leave them alone for now.
> 
> Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>

Acked-by: Tejun Heo <tj@xxxxxxxxxx>

Thanks.

-- 
tejun