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Diffstat (limited to 'Documentation/cgroups')
| -rw-r--r-- | Documentation/cgroups/blkio-controller.txt | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/Documentation/cgroups/blkio-controller.txt b/Documentation/cgroups/blkio-controller.txt index d6da611f8f63..4ed7b5ceeed2 100644 --- a/Documentation/cgroups/blkio-controller.txt +++ b/Documentation/cgroups/blkio-controller.txt @@ -89,6 +89,33 @@ Throttling/Upper Limit policy Limits for writes can be put using blkio.write_bps_device file. +Hierarchical Cgroups +==================== +- Currently none of the IO control policy supports hierarhical groups. But + cgroup interface does allow creation of hierarhical cgroups and internally + IO policies treat them as flat hierarchy. + + So this patch will allow creation of cgroup hierarhcy but at the backend + everything will be treated as flat. So if somebody created a hierarchy like + as follows. + + root + / \ + test1 test2 + | + test3 + + CFQ and throttling will practically treat all groups at same level. + + pivot + / | \ \ + root test1 test2 test3 + + Down the line we can implement hierarchical accounting/control support + and also introduce a new cgroup file "use_hierarchy" which will control + whether cgroup hierarchy is viewed as flat or hierarchical by the policy.. + This is how memory controller also has implemented the things. + Various user visible config options =================================== CONFIG_BLK_CGROUP |