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

From: Jens Axboe
Date: Wed Jul 07 2021 - 11:38:59 EST


On 7/6/21 7:56 PM, 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.

Applied, thanks.

--
Jens Axboe