Re: [PATCH 33/33] blk-throttle: implement proper hierarchy support

From: Vivek Goyal
Date: Tue May 07 2013 - 09:55:33 EST


On Mon, May 06, 2013 at 03:46:12PM -0700, Tejun Heo wrote:
> With the recent updates, blk-throttle is finally ready for proper
> hierarchy support. Dispatching now honors service_queue->parent_sq
> and propagates correctly. The only thing missing is setting
> ->parent_sq correctly so that throtl_grp hierarchy matches the cgroup
> hierarchy.
>
> This patch updates throtl_pd_init() such that service_queues form the
> same hierarchy as the cgroup hierarchy if sane_behavior is enabled.
> As this concludes proper hierarchy support for blkcg, the shameful
> .broken_hierarchy tag is removed from blkio_subsys.
>
> Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
> Cc: Li Zefan <lizefan@xxxxxxxxxx>
> ---
> block/blk-cgroup.c | 8 --------
> block/blk-throttle.c | 22 +++++++++++++++++++++-
> include/linux/cgroup.h | 2 ++
> 3 files changed, 23 insertions(+), 9 deletions(-)
>
> diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
> index af2ca27..8d9edc8 100644
> --- a/block/blk-cgroup.c
> +++ b/block/blk-cgroup.c
> @@ -911,14 +911,6 @@ struct cgroup_subsys blkio_subsys = {
> .subsys_id = blkio_subsys_id,
> .base_cftypes = blkcg_files,
> .module = THIS_MODULE,
> -
> - /*
> - * blkio subsystem is utterly broken in terms of hierarchy support.
> - * It treats all cgroups equally regardless of where they're
> - * located in the hierarchy - all cgroups are treated as if they're
> - * right below the root. Fix it and remove the following.
> - */
> - .broken_hierarchy = true,

So if somebody does not specify __DEVEL_sane_behavior, hierarchy is
still broken. Should we continue to display the message in that case?

Vivek
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