Messages in this thread | | | Subject | Re: [PATCH -v2 13/18] sched/fair: Propagate an effective runnable_load_avg | From | Dietmar Eggemann <> | Date | Mon, 2 Oct 2017 18:46:32 +0100 |
| |
On 01/09/17 14:21, Peter Zijlstra wrote: > The load balancer uses runnable_load_avg as load indicator. For > !cgroup this is: > > runnable_load_avg = \Sum se->avg.load_avg ; where se->on_rq > > That is, a direct sum of all runnable tasks on that runqueue. As > opposed to load_avg, which is a sum of all tasks on the runqueue, > which includes a blocked component. > > However, in the cgroup case, this comes apart since the group entities > are always runnable, even if most of their constituent entities are > blocked. > > Therefore introduce a runnable_weight which for task entities is the > same as the regular weight, but for group entities is a fraction of > the entity weight and represents the runnable part of the group > runqueue. > > Then propagate this load through the PELT hierarchy to arrive at an > effective runnable load avgerage -- which we should not confuse with > the canonical runnable load average. > > Suggested-by: Tejun Heo <tj@kernel.org> > Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> > --- > include/linux/sched.h | 3 > kernel/sched/debug.c | 8 ++ > kernel/sched/fair.c | 173 ++++++++++++++++++++++++++++++++------------------ > kernel/sched/sched.h | 3 > 4 files changed, 125 insertions(+), 62 deletions(-)
[...]
> @@ -2931,31 +2949,45 @@ static long calc_cfs_shares(struct cfs_r > > static inline int throttled_hierarchy(struct cfs_rq *cfs_rq); > > -static void update_cfs_shares(struct sched_entity *se) > +/* > + * Recomputes the group entity based on the current state of its group > + * runqueue. > + */ > +static void update_cfs_group(struct sched_entity *se)
update_cfs_share(s)() is still mentioned in the function header of update_tg_load_avg() and update_cfs_rq_load_avg().
Should we rename those comments with this patch?
IMHO, the comment for update_tg_load_avg() is still true whereas the one for update_cfs_rq_load_avg() mentions cfs_rq->avg as cfs_rq->avg.load_avg (or cfs_rq_load_avg()) and update_cfs_group() doesn't use it anymore. It's now used in calc_group_runnable() and calc_group_shares() instead.
[...]
| |