A-Team_Digital_Solutions/android_kernel_motorola_sm6375
Watch
2
0
Fork
You've already forked android_kernel_motorola_sm6375
 0
mirror of https://github.com/BobTheBlinker/android_kernel_motorola_sm6375.git synced 2026-10-28 10:41:38 -04:00
Code Issues Projects Releases Packages Wiki Activity

blkio: Recalculate the throttled bio dispatch time upon throttle limit change

Browse source 
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 <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
This commit is contained in:
Vivek Goyal 2010-10-01 14:49:49 +02:00 • committed by Jens Axboe
commit fe0714377e
4 changed files with 139 additions and 35 deletions
Download patch file Download diff file Expand all files Collapse all files

15
block/blk-cgroup.c
View file

@ -124,7 +124,8 @@ blkio_update_group_weight(struct blkio_group *blkg, unsigned int weight)
if (blkiop->plid != blkg->plid)
continue;
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);
}
}