Re: [PATCH 0/3] blkcg: decouple cgroup v1 I/O accounting from throttling

[Tejun Heo]

On Tue, Nov 10, 2026 at 06:31:58PM +0800, Zhe Liu wrote:
> Commit a3166c51702b ("blk-throttle: delay initialization until
> configuration") deferred throttle policy activation until an I/O limit is
> configured. However, cgroup v1 accounting still lives in the throttle
> policy and is performed after the activation check in blk_should_throtl().
> Without an activated throttle policy, v1 statistics such as
> blkio.throttle.io_service_bytes remain zero even while I/O is issued.
> 
> This forces cgroup v1 users to configure the throttle policy just
> to obtain I/O statistics, even when no throttling is needed.

Maybe just add a module option or sth to blk-throtl to initialize eagerly? I
don't think it makes sense to update cgroup1 significnatly at this point.

Thanks.

-- 
tejun