Messages in this thread |  | | Date | Tue, 8 Jan 2013 10:51:14 -0500 | From | Vivek Goyal <> | Subject | Re: [PATCH 12/24] cfq-iosched: implement cfq_group->nr_active and ->children_weight |
| |
On Fri, Dec 28, 2012 at 12:35:34PM -0800, Tejun Heo wrote: > To prepare for blkcg hierarchy support, add cfqg->nr_active and > ->children_weight. cfqg->nr_active counts the number of active cfqgs > at the cfqg's level and ->children_weight is sum of weights of those > cfqgs. The level covers itself (cfqg->leaf_weight) and immediate > children. > > The two values are updated when a cfqg enters and leaves the group > service tree. Unless the hierarchy is very deep, the added overhead > should be negligible. > > Currently, the parent is determined using cfqg_flat_parent() which > makes the root cfqg the parent of all other cfqgs. This is to make > the transition to hierarchy-aware scheduling gradual. Scheduling > logic will be converted to use cfqg->children_weight without actually > changing the behavior. When everything is ready, > blkcg_weight_parent() will be replaced with proper parent function. > > This patch doesn't introduce any behavior chagne. > > v2: s/cfqg->level_weight/cfqg->children_weight/ as per Vivek. > > Signed-off-by: Tejun Heo <tj@kernel.org> > Cc: Vivek Goyal <vgoyal@redhat.com>
Looks good to me.
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Vivek
|  |