| Message ID | 1432329245-5844-25-git-send-email-tj@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri 22-05-15 17:13:38, Tejun Heo wrote: > A blkg (blkcg_gq) can be congested and decongested independently from > other blkgs on the same request_queue. Accordingly, for cgroup > writeback support, the congestion status at bdi (backing_dev_info) > should be split and updated separately from matching blkg's. > > This patch prepares by adding blkg->wb_congested and associating a > blkg with its matching per-blkcg bdi_writeback_congested on creation. > > v2: Updated to associate bdi_writeback_congested instead of > bdi_writeback. > > Signed-off-by: Tejun Heo <tj@kernel.org> > Cc: Jens Axboe <axboe@kernel.dk> > Cc: Jan Kara <jack@suse.cz> > Cc: Vivek Goyal <vgoyal@redhat.com> Looks good to me. You can add: Reviewed-by: Jan Kara <jack@suse.com> > --- > block/blk-cgroup.c | 17 +++++++++++++++-- > include/linux/blk-cgroup.h | 6 ++++++ > 2 files changed, 21 insertions(+), 2 deletions(-) > > diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c > index 979cfdb..31610ae 100644 > --- a/block/blk-cgroup.c > +++ b/block/blk-cgroup.c > @@ -182,6 +182,7 @@ static struct blkcg_gq *blkg_create(struct blkcg *blkcg, > struct blkcg_gq *new_blkg) > { > struct blkcg_gq *blkg; > + struct bdi_writeback_congested *wb_congested; > int i, ret; > > WARN_ON_ONCE(!rcu_read_lock_held()); > @@ -193,22 +194,30 @@ static struct blkcg_gq *blkg_create(struct blkcg *blkcg, > goto err_free_blkg; > } > > + wb_congested = wb_congested_get_create(&q->backing_dev_info, > + blkcg->css.id, GFP_ATOMIC); > + if (!wb_congested) { > + ret = -ENOMEM; > + goto err_put_css; > + } > + > /* allocate */ > if (!new_blkg) { > new_blkg = blkg_alloc(blkcg, q, GFP_ATOMIC); > if (unlikely(!new_blkg)) { > ret = -ENOMEM; > - goto err_put_css; > + goto err_put_congested; > } > } > blkg = new_blkg; > + blkg->wb_congested = wb_congested; > > /* link parent */ > if (blkcg_parent(blkcg)) { > blkg->parent = __blkg_lookup(blkcg_parent(blkcg), q, false); > if (WARN_ON_ONCE(!blkg->parent)) { > ret = -EINVAL; > - goto err_put_css; > + goto err_put_congested; > } > blkg_get(blkg->parent); > } > @@ -245,6 +254,8 @@ static struct blkcg_gq *blkg_create(struct blkcg *blkcg, > blkg_put(blkg); > return ERR_PTR(ret); > > +err_put_congested: > + wb_congested_put(wb_congested); > err_put_css: > css_put(&blkcg->css); > err_free_blkg: > @@ -391,6 +402,8 @@ void __blkg_release_rcu(struct rcu_head *rcu_head) > if (blkg->parent) > blkg_put(blkg->parent); > > + wb_congested_put(blkg->wb_congested); > + > blkg_free(blkg); > } > EXPORT_SYMBOL_GPL(__blkg_release_rcu); > diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h > index 3033eb1..07a32b8 100644 > --- a/include/linux/blk-cgroup.h > +++ b/include/linux/blk-cgroup.h > @@ -99,6 +99,12 @@ struct blkcg_gq { > struct hlist_node blkcg_node; > struct blkcg *blkcg; > > + /* > + * Each blkg gets congested separately and the congestion state is > + * propagated to the matching bdi_writeback_congested. > + */ > + struct bdi_writeback_congested *wb_congested; > + > /* all non-root blkcg_gq's are guaranteed to have access to parent */ > struct blkcg_gq *parent; > > -- > 2.4.0 >
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 979cfdb..31610ae 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -182,6 +182,7 @@ static struct blkcg_gq *blkg_create(struct blkcg *blkcg, struct blkcg_gq *new_blkg) { struct blkcg_gq *blkg; + struct bdi_writeback_congested *wb_congested; int i, ret; WARN_ON_ONCE(!rcu_read_lock_held()); @@ -193,22 +194,30 @@ static struct blkcg_gq *blkg_create(struct blkcg *blkcg, goto err_free_blkg; } + wb_congested = wb_congested_get_create(&q->backing_dev_info, + blkcg->css.id, GFP_ATOMIC); + if (!wb_congested) { + ret = -ENOMEM; + goto err_put_css; + } + /* allocate */ if (!new_blkg) { new_blkg = blkg_alloc(blkcg, q, GFP_ATOMIC); if (unlikely(!new_blkg)) { ret = -ENOMEM; - goto err_put_css; + goto err_put_congested; } } blkg = new_blkg; + blkg->wb_congested = wb_congested; /* link parent */ if (blkcg_parent(blkcg)) { blkg->parent = __blkg_lookup(blkcg_parent(blkcg), q, false); if (WARN_ON_ONCE(!blkg->parent)) { ret = -EINVAL; - goto err_put_css; + goto err_put_congested; } blkg_get(blkg->parent); } @@ -245,6 +254,8 @@ static struct blkcg_gq *blkg_create(struct blkcg *blkcg, blkg_put(blkg); return ERR_PTR(ret); +err_put_congested: + wb_congested_put(wb_congested); err_put_css: css_put(&blkcg->css); err_free_blkg: @@ -391,6 +402,8 @@ void __blkg_release_rcu(struct rcu_head *rcu_head) if (blkg->parent) blkg_put(blkg->parent); + wb_congested_put(blkg->wb_congested); + blkg_free(blkg); } EXPORT_SYMBOL_GPL(__blkg_release_rcu); diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h index 3033eb1..07a32b8 100644 --- a/include/linux/blk-cgroup.h +++ b/include/linux/blk-cgroup.h @@ -99,6 +99,12 @@ struct blkcg_gq { struct hlist_node blkcg_node; struct blkcg *blkcg; + /* + * Each blkg gets congested separately and the congestion state is + * propagated to the matching bdi_writeback_congested. + */ + struct bdi_writeback_congested *wb_congested; + /* all non-root blkcg_gq's are guaranteed to have access to parent */ struct blkcg_gq *parent;
A blkg (blkcg_gq) can be congested and decongested independently from other blkgs on the same request_queue. Accordingly, for cgroup writeback support, the congestion status at bdi (backing_dev_info) should be split and updated separately from matching blkg's. This patch prepares by adding blkg->wb_congested and associating a blkg with its matching per-blkcg bdi_writeback_congested on creation. v2: Updated to associate bdi_writeback_congested instead of bdi_writeback. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jan Kara <jack@suse.cz> Cc: Vivek Goyal <vgoyal@redhat.com> --- block/blk-cgroup.c | 17 +++++++++++++++-- include/linux/blk-cgroup.h | 6 ++++++ 2 files changed, 21 insertions(+), 2 deletions(-)