On Fri, Aug 31, 2018 at 04:16:09PM -0700, Tejun Heo wrote: > Hello, > > On Thu, Aug 30, 2018 at 09:53:47PM -0400, Dennis Zhou wrote: > > From: "Dennis Zhou (Facebook)" <dennisszhou@xxxxxxxxx> > > > > Previously, blkg's were only assigned as needed by blk-iolatency and > > blk-throttle. bio->css was also always being associated while blkg was > > being looked up and then thrown away in blkcg_bio_issue_check. > > > > This patch beings the cleanup of bio->css and bio->bi_blkg by always > ^ > begins > Thanks! > > +int bio_associate_create_blkg(struct request_queue *q, struct bio *bio) > > +{ > > + struct blkcg *blkcg; > > + struct blkcg_gq *blkg; > > + int ret = 0; > > + > > + /* someone has already associated this bio with a blkg */ > > + if (bio->bi_blkg) > > + return ret; > > + > > + rcu_read_lock(); > > + > > + bio_associate_blkcg(bio, NULL); > > + blkcg = bio_blkcg(bio); > > + > > + if (!blkcg->css.parent) { > > + ret = bio_associate_blkg(bio, q->root_blkg); > > + goto assoc_out; > > + } > > + > > + blkg = blkg_lookup_create(blkcg, q); > > + if (IS_ERR(blkg)) > > + blkg = q->root_blkg; > > + > > + ret = bio_associate_blkg(bio, blkg); > > +assoc_out: > > Maybe if/else instead of goto? > Yeah, no need for goto. Thanks, Dennis