diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2013-07-11 16:03:24 -0400 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-07-11 16:03:24 -0400 |
commit | 36805aaea5ae3cf1bb32f1643e0a800bb69f0d5b (patch) | |
tree | 5565132549a0733772b3a2ac6b5cda516ea8cdce /Documentation | |
parent | 6d2fa9e141ea56a571ec842fd4f3a86bea44a203 (diff) | |
parent | d50235b7bc3ee0a0427984d763ea7534149531b4 (diff) |
Merge branch 'for-3.11/core' of git://git.kernel.dk/linux-block
Pull core block IO updates from Jens Axboe:
"Here are the core IO block bits for 3.11. It contains:
- A tweak to the reserved tag logic from Jan, for weirdo devices with
just 3 free tags. But for those it improves things substantially
for random writes.
- Periodic writeback fix from Jan. Marked for stable as well.
- Fix for a race condition in IO scheduler switching from Jianpeng.
- The hierarchical blk-cgroup support from Tejun. This is the grunt
of the series.
- blk-throttle fix from Vivek.
Just a note that I'm in the middle of a relocation, whole family is
flying out tomorrow. Hence I will be awal the remainder of this week,
but back at work again on Monday the 15th. CC'ing Tejun, since any
potential "surprises" will most likely be from the blk-cgroup work.
But it's been brewing for a while and sitting in my tree and
linux-next for a long time, so should be solid."
* 'for-3.11/core' of git://git.kernel.dk/linux-block: (36 commits)
elevator: Fix a race in elevator switching
block: Reserve only one queue tag for sync IO if only 3 tags are available
writeback: Fix periodic writeback after fs mount
blk-throttle: implement proper hierarchy support
blk-throttle: implement throtl_grp->has_rules[]
blk-throttle: Account for child group's start time in parent while bio climbs up
blk-throttle: add throtl_qnode for dispatch fairness
blk-throttle: make throtl_pending_timer_fn() ready for hierarchy
blk-throttle: make tg_dispatch_one_bio() ready for hierarchy
blk-throttle: make blk_throtl_bio() ready for hierarchy
blk-throttle: make blk_throtl_drain() ready for hierarchy
blk-throttle: dispatch from throtl_pending_timer_fn()
blk-throttle: implement dispatch looping
blk-throttle: separate out throtl_service_queue->pending_timer from throtl_data->dispatch_work
blk-throttle: set REQ_THROTTLED from throtl_charge_bio() and gate stats update with it
blk-throttle: implement sq_to_tg(), sq_to_td() and throtl_log()
blk-throttle: add throtl_service_queue->parent_sq
blk-throttle: generalize update_disptime optimization in blk_throtl_bio()
blk-throttle: dispatch to throtl_data->service_queue.bio_lists[]
blk-throttle: move bio_lists[] and friends to throtl_service_queue
...
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/cgroups/blkio-controller.txt | 29 |
1 files changed, 15 insertions, 14 deletions
diff --git a/Documentation/cgroups/blkio-controller.txt b/Documentation/cgroups/blkio-controller.txt index da272c8f44e7..cd556b914786 100644 --- a/Documentation/cgroups/blkio-controller.txt +++ b/Documentation/cgroups/blkio-controller.txt | |||
@@ -94,11 +94,13 @@ Throttling/Upper Limit policy | |||
94 | 94 | ||
95 | Hierarchical Cgroups | 95 | Hierarchical Cgroups |
96 | ==================== | 96 | ==================== |
97 | - Currently only CFQ supports hierarchical groups. For throttling, | ||
98 | cgroup interface does allow creation of hierarchical cgroups and | ||
99 | internally it treats them as flat hierarchy. | ||
100 | 97 | ||
101 | If somebody created a hierarchy like as follows. | 98 | Both CFQ and throttling implement hierarchy support; however, |
99 | throttling's hierarchy support is enabled iff "sane_behavior" is | ||
100 | enabled from cgroup side, which currently is a development option and | ||
101 | not publicly available. | ||
102 | |||
103 | If somebody created a hierarchy like as follows. | ||
102 | 104 | ||
103 | root | 105 | root |
104 | / \ | 106 | / \ |
@@ -106,21 +108,20 @@ Hierarchical Cgroups | |||
106 | | | 108 | | |
107 | test3 | 109 | test3 |
108 | 110 | ||
109 | CFQ will handle the hierarchy correctly but and throttling will | 111 | CFQ by default and throttling with "sane_behavior" will handle the |
110 | practically treat all groups at same level. For details on CFQ | 112 | hierarchy correctly. For details on CFQ hierarchy support, refer to |
111 | hierarchy support, refer to Documentation/block/cfq-iosched.txt. | 113 | Documentation/block/cfq-iosched.txt. For throttling, all limits apply |
112 | Throttling will treat the hierarchy as if it looks like the | 114 | to the whole subtree while all statistics are local to the IOs |
113 | following. | 115 | directly generated by tasks in that cgroup. |
116 | |||
117 | Throttling without "sane_behavior" enabled from cgroup side will | ||
118 | practically treat all groups at same level as if it looks like the | ||
119 | following. | ||
114 | 120 | ||
115 | pivot | 121 | pivot |
116 | / / \ \ | 122 | / / \ \ |
117 | root test1 test2 test3 | 123 | root test1 test2 test3 |
118 | 124 | ||
119 | Nesting cgroups, while allowed, isn't officially supported and blkio | ||
120 | genereates warning when cgroups nest. Once throttling implements | ||
121 | hierarchy support, hierarchy will be supported and the warning will | ||
122 | be removed. | ||
123 | |||
124 | Various user visible config options | 125 | Various user visible config options |
125 | =================================== | 126 | =================================== |
126 | CONFIG_BLK_CGROUP | 127 | CONFIG_BLK_CGROUP |