[dm-devel] Re: [PATCH 05/18] io-controller: Common hierarchical fair queuing code in elevaotor layer

Vivek Goyal vgoyal at redhat.com
Fri May 8 12:45:44 UTC 2009


On Thu, May 07, 2009 at 03:42:37PM +0800, Gui Jianfeng wrote:
> Vivek Goyal wrote:
> > This patch enables hierarchical fair queuing in common layer. It is
> > controlled by config option CONFIG_GROUP_IOSCHED.
> ...
> > +}
> > +
> > +void iocg_destroy(struct cgroup_subsys *subsys, struct cgroup *cgroup)
> > +{
> > +	struct io_cgroup *iocg = cgroup_to_io_cgroup(cgroup);
> > +	struct hlist_node *n, *tmp;
> > +	struct io_group *iog;
> > +
> > +	/*
> > +	 * Since we are destroying the cgroup, there are no more tasks
> > +	 * referencing it, and all the RCU grace periods that may have
> > +	 * referenced it are ended (as the destruction of the parent
> > +	 * cgroup is RCU-safe); bgrp->group_data will not be accessed by
> > +	 * anything else and we don't need any synchronization.
> > +	 */
> > +	hlist_for_each_entry_safe(iog, n, tmp, &iocg->group_data, group_node)
> > +		io_destroy_group(iocg, iog);
> > +
> > +	BUG_ON(!hlist_empty(&iocg->group_data));
> > +
> 
>     Hi Vivek,
> 
>     IMHO, free_css_id() needs to be called here.
> 

Thanks. Sure, will do in next version.

Thanks
Vivek




More information about the dm-devel mailing list