path: root/block/blk-cgroup.h
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.h
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.h')
1 files changed, 11 insertions, 10 deletions
diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index 2070053a30b..034c35562db 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -186,16 +186,17 @@ extern unsigned int blkcg_get_write_iops(struct blkio_cgroup *blkcg,
dev_t dev);
typedef void (blkio_unlink_group_fn) (void *key, struct blkio_group *blkg);
-typedef void (blkio_update_group_weight_fn) (struct blkio_group *blkg,
- unsigned int weight);
-typedef void (blkio_update_group_read_bps_fn) (struct blkio_group *blkg,
- u64 read_bps);
-typedef void (blkio_update_group_write_bps_fn) (struct blkio_group *blkg,
- u64 write_bps);
-typedef void (blkio_update_group_read_iops_fn) (struct blkio_group *blkg,
- unsigned int read_iops);
-typedef void (blkio_update_group_write_iops_fn) (struct blkio_group *blkg,
- unsigned int write_iops);
+typedef void (blkio_update_group_weight_fn) (void *key,
+ struct blkio_group *blkg, unsigned int weight);
+typedef void (blkio_update_group_read_bps_fn) (void * key,
+ struct blkio_group *blkg, u64 read_bps);
+typedef void (blkio_update_group_write_bps_fn) (void *key,
+ struct blkio_group *blkg, u64 write_bps);
+typedef void (blkio_update_group_read_iops_fn) (void *key,
+ struct blkio_group *blkg, unsigned int read_iops);
+typedef void (blkio_update_group_write_iops_fn) (void *key,
+ struct blkio_group *blkg, unsigned int write_iops);
struct blkio_policy_ops {
blkio_unlink_group_fn *blkio_unlink_group_fn;