path: root/block/blk-cgroup.c
diff options
authorVivek Goyal <vgoyal@redhat.com>2010-10-01 14:49:49 +0200
committerJens Axboe <jaxboe@fusionio.com>2010-10-01 14:49:49 +0200
commitfe0714377ee2ca161bf2afb7773e22f15f1786d4 (patch)
tree09f5e8686d741d012333c92251b8cc66793ef916 /block/blk-cgroup.c
parent02977e4af7ed3b478c505e50491ffdf3e1314cf4 (diff)
blkio: Recalculate the throttled bio dispatch time upon throttle limit change
o Currently any cgroup throttle limit changes are processed asynchronousy and the change does not take affect till a new bio is dispatched from same group. o It might happen that a user sets a redicuously low limit on throttling. Say 1 bytes per second on reads. In such cases simple operations like mount a disk can wait for a very long time. o Once bio is throttled, there is no easy way to come out of that wait even if user increases the read limit later. o This patch fixes it. Now if a user changes the cgroup limits, we recalculate the bio dispatch time according to new limits. o Can't take queueu lock under blkcg_lock, hence after the change I wake up the dispatch thread again which recalculates the time. So there are some variables being synchronized across two threads without lock and I had to make use of barriers. Hoping I have used barriers correctly. Any review of memory barrier code especially will help. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Diffstat (limited to 'block/blk-cgroup.c')
1 files changed, 10 insertions, 5 deletions
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index b06ca70354e..52c12130a5d 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -124,7 +124,8 @@ blkio_update_group_weight(struct blkio_group *blkg, unsigned int weight)
if (blkiop->plid != blkg->plid)
if (blkiop->ops.blkio_update_group_weight_fn)
- blkiop->ops.blkio_update_group_weight_fn(blkg, weight);
+ blkiop->ops.blkio_update_group_weight_fn(blkg->key,
+ blkg, weight);
@@ -141,11 +142,13 @@ static inline void blkio_update_group_bps(struct blkio_group *blkg, u64 bps,
if (fileid == BLKIO_THROTL_read_bps_device
&& blkiop->ops.blkio_update_group_read_bps_fn)
- blkiop->ops.blkio_update_group_read_bps_fn(blkg, bps);
+ blkiop->ops.blkio_update_group_read_bps_fn(blkg->key,
+ blkg, bps);
if (fileid == BLKIO_THROTL_write_bps_device
&& blkiop->ops.blkio_update_group_write_bps_fn)
- blkiop->ops.blkio_update_group_write_bps_fn(blkg, bps);
+ blkiop->ops.blkio_update_group_write_bps_fn(blkg->key,
+ blkg, bps);
@@ -162,11 +165,13 @@ static inline void blkio_update_group_iops(struct blkio_group *blkg,
if (fileid == BLKIO_THROTL_read_iops_device
&& blkiop->ops.blkio_update_group_read_iops_fn)
- blkiop->ops.blkio_update_group_read_iops_fn(blkg, iops);
+ blkiop->ops.blkio_update_group_read_iops_fn(blkg->key,
+ blkg, iops);
if (fileid == BLKIO_THROTL_write_iops_device
&& blkiop->ops.blkio_update_group_write_iops_fn)
- blkiop->ops.blkio_update_group_write_iops_fn(blkg,iops);
+ blkiop->ops.blkio_update_group_write_iops_fn(blkg->key,
+ blkg,iops);