On Sun, Nov 19, 2017 at 9:00 PM, Joseph Qi <jiangqi903@xxxxxxxxx> wrote: > From: Joseph Qi <qijiang.qj@xxxxxxxxxxxxxxx> > > dm device set QUEUE_FLAG_NONROT in resume, which is after register > queue. That is to mean, the previous initialization in > blk_throtl_register_queue is wrong in this case. > Fix it by checking and then updating the info during root tg > initialization as we don't have a better choice. Given DM motivated this change, curious why you didn't send this to dm-devel? In any case, not sure why you need to reference "resume". Very few people will appreciate that detail. Better to just say: DM device sets QUEUE_FLAG_NONROT after the queue is registered. > Signed-off-by: Joseph Qi <qijiang.qj@xxxxxxxxxxxxxxx> > --- > block/blk-throttle.c | 17 +++++++++++++++++ > 1 file changed, 17 insertions(+) > > diff --git a/block/blk-throttle.c b/block/blk-throttle.c > index bf52035..6d6b220 100644 > --- a/block/blk-throttle.c > +++ b/block/blk-throttle.c > @@ -541,6 +541,23 @@ static void throtl_pd_init(struct blkg_policy_data *pd) > if (cgroup_subsys_on_dfl(io_cgrp_subsys) && blkg->parent) > sq->parent_sq = &blkg_to_tg(blkg->parent)->service_queue; > tg->td = td; > + > + /* > + * dm device set QUEUE_FLAG_NONROT in resume, which is after resister > + * queue, so the previous initialization is wrong in this case. Check > + * and update it here. > + */ typo: s/resister/register/ But again, best to say: DM device sets QUEUE_FLAG_NONROT after the queue is registered, ... Also, an alternative to your patch would be to have DM's dm_table_set_restrictions() call a blk-throttle function to setup blk-throttle after it is done setting queue flags? Saves all other drivers from having to run this 2 stage initialization code.. just a thought. Mike
