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Commit 02977e4af7ed3b478c505e50491ffdf3e1314cf4

Authored by Vivek Goyal
Committed by Jens Axboe
1 parent 61014e96e6
Exists in master and in 7 other branches imx_3.0.35_4.1.0, imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga, smarc-l5.0.0_1.0.0-ga

blkio: Add root group to td->tg_list 

o Currently all the dynamically allocated groups, except root grp is added
  to td->tg_list. This was not a problem so far but in next patch I will
  travel through td->tg_list to process any updates of limits on the group.
  If root group is not in tg_list, then root group's updates are not
  processed.

o It is better to root group also to tg_list instead of doing special
  processing for it during limit updates.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

Showing 1 changed file with 13 additions and 4 deletions Side-by-side Diff

block/blk-throttle.c
Diff comments   View file @ 02977e4
... ... @@ -87,7 +87,7 @@
87 87 unsigned int nr_queued[2];
88 88  
89 89 /*
90   - * number of total undestroyed groups (excluding root group)
  90 + * number of total undestroyed groups
91 91 */
92 92 unsigned int nr_undestroyed_grps;
93 93  
94 94  
... ... @@ -940,8 +940,18 @@
940 940 /* Practically unlimited BW */
941 941 tg->bps[0] = tg->bps[1] = -1;
942 942 tg->iops[0] = tg->iops[1] = -1;
943   - atomic_set(&tg->ref, 1);
944 943  
  944 + /*
  945 + * Set root group reference to 2. One reference will be dropped when
  946 + * all groups on tg_list are being deleted during queue exit. Other
  947 + * reference will remain there as we don't want to delete this group
  948 + * as it is statically allocated and gets destroyed when throtl_data
  949 + * goes away.
  950 + */
  951 + atomic_set(&tg->ref, 2);
  952 + hlist_add_head(&tg->tg_node, &td->tg_list);
  953 + td->nr_undestroyed_grps++;
  954 +
945 955 INIT_DELAYED_WORK(&td->throtl_work, blk_throtl_work);
946 956  
947 957 rcu_read_lock();
948 958  
... ... @@ -966,10 +976,9 @@
966 976  
967 977 spin_lock_irq(q->queue_lock);
968 978 throtl_release_tgs(td);
969   - blkiocg_del_blkio_group(&td->root_tg.blkg);
970 979  
971 980 /* If there are other groups */
972   - if (td->nr_undestroyed_grps >= 1)
  981 + if (td->nr_undestroyed_grps > 0)
973 982 wait = true;
974 983  
975 984 spin_unlock_irq(q->queue_lock);