On 11/05/2020 22:44, Phil Auld wrote: > On Mon, May 11, 2020 at 09:25:43PM +0200 Vincent Guittot wrote: >> On Thu, 7 May 2020 at 22:36, Phil Auld <pa...@redhat.com> wrote: >>> >>> sched/fair: Fix enqueue_task_fair warning some more >>> >>> The recent patch, fe61468b2cb (sched/fair: Fix enqueue_task_fair warning) >>> did not fully resolve the issues with the rq->tmp_alone_branch != >>> &rq->leaf_cfs_rq_list warning in enqueue_task_fair. There is a case where >>> the first for_each_sched_entity loop exits due to on_rq, having incompletely >>> updated the list. In this case the second for_each_sched_entity loop can >>> further modify se. The later code to fix up the list management fails to do >>> what is needed because se no longer points to the sched_entity which broke >>> out of the first loop. >>> >>> Address this by calling leaf_add_rq_list if there are throttled parents >>> while >>> doing the second for_each_sched_entity loop. >>> >> >> Fixes: fe61468b2cb (sched/fair: Fix enqueue_task_fair warning) >> >>> Suggested-by: Vincent Guittot <vincent.guit...@linaro.org> >>> Signed-off-by: Phil Auld <pa...@redhat.com> >>> Cc: Peter Zijlstra (Intel) <pet...@infradead.org> >>> Cc: Vincent Guittot <vincent.guit...@linaro.org> >>> Cc: Ingo Molnar <mi...@kernel.org> >>> Cc: Juri Lelli <juri.le...@redhat.com> >> >> With the Fixes tag and the typo mentioned by Tao >> > > Right, that last line of the commit message should read "list_add_leaf_cfs_rq" > > >> Reviewed-by: Vincent Guittot <vincent.guit...@linaro.org> > > Thanks Vincent. > > Peter/Ingo, do you want me to resend or can you fix when applying?
Maybe you could add that 'the throttled parent was already added back to the list by a task enqueue in a parallel child hierarchy'. IMHO, this is part of the description because otherwise the throttled parent would have connected the branch. And the not-adding of the intermediate child cfs_rq would have gone unnoticed. Reviewed-by: Dietmar Eggemann <dietmar.eggem...@arm.com> [...]
