On Mon, Nov 13, 2017 at 12:15:23PM -0800, Tejun Heo wrote: > From c856a199ec70e4022e997609f1b17b9106408777 Mon Sep 17 00:00:00 2001 > From: Tejun Heo <tj@xxxxxxxxxx> > Date: Mon, 13 Nov 2017 12:11:57 -0800 > > On the legacy request_queue, each blkcg_gq has a dedicated > request_list that requests for the cgroup are allocated from. Each > request points to the originating request_list and cgroup membership > can be determined by examining which cgroup the associated > request_list belongs to. > > This doesn't work for blk-mq which doesn't use request_list. Let's > associate each request with the blkcg_gq directly. Except for minor > wrapper changes, this doesn't affect the legacy request_queue and will > allow blk-mq to track each request's cgroup association. > > v2: Build fix for !CONFIG_BLK_CGROUP. > > Signed-off-by: Tejun Heo <tj@xxxxxxxxxx> > --- > block/blk-mq.c | 2 +- > include/linux/blk-cgroup.h | 7 +++++-- > include/linux/blkdev.h | 2 +- > 3 files changed, 7 insertions(+), 4 deletions(-) > > diff --git a/block/blk-mq.c b/block/blk-mq.c > index 98a1860..af958c4 100644 > --- a/block/blk-mq.c > +++ b/block/blk-mq.c > @@ -306,7 +306,7 @@ static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data, > rq->part = NULL; > rq->start_time = jiffies; > #ifdef CONFIG_BLK_CGROUP > - rq->rl = NULL; > + rq->blkg = NULL; > set_start_time_ns(rq); > rq->io_start_time_ns = 0; > #endif > diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h > index c0d4736..47db75a 100644 > --- a/include/linux/blk-cgroup.h > +++ b/include/linux/blk-cgroup.h > @@ -463,7 +463,7 @@ static inline void blk_put_rl(struct request_list *rl) > */ > static inline void blk_rq_set_rl(struct request *rq, struct request_list *rl) > { > - rq->rl = rl; > + rq->blkg = rl->blkg; > } After patch 5, we don't really need the blk_put_rl, blk_get_rl, blk_rq_set_rl functions. I'd like to delete them and only keep blk_rq_rl. The name blk_rq_set_rl is confusing too. Thanks, Shaohua > /** > @@ -474,7 +474,10 @@ static inline void blk_rq_set_rl(struct request *rq, struct request_list *rl) > */ > static inline struct request_list *blk_rq_rl(struct request *rq) > { > - return rq->rl; > + if (!rq->blkg->parent) > + return &rq->q->root_rl; > + else > + return &rq->blkg->rl; > } > > struct request_list *__blk_queue_next_rl(struct request_list *rl, > diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h > index 8da6637..6ec1067 100644 > --- a/include/linux/blkdev.h > +++ b/include/linux/blkdev.h > @@ -206,7 +206,7 @@ struct request { > unsigned long start_time; > struct blk_issue_stat issue_stat; > #ifdef CONFIG_BLK_CGROUP > - struct request_list *rl; /* rl this rq is alloced from */ > + struct blkcg_gq *blkg; /* blkg of this rq */ > unsigned long long start_time_ns; > unsigned long long io_start_time_ns; /* when passed to hardware */ > #endif > -- > 2.9.5 > -- To unsubscribe from this list: send the line "unsubscribe cgroups" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html