| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <4D620375.1000308@cn.fujitsu.com> Date: Mon, 21 Feb 2011 14:17:25 +0800 From: Gui Jianfeng <guijianfeng@...fujitsu.com> To: Vivek Goyal <vgoyal@...hat.com>, Jens Axboe <axboe@...nel.dk> CC: Justin TerAvest <teravest@...gle.com>, "jmoyer@...hat.com" <jmoyer@...hat.com>, Chad Talbott <ctalbott@...gle.com>, lkml <linux-kernel@...r.kernel.org> Subject: [PATCH 6/6 v5] blkio-cgroup: Document for blkio.use_hierarchy interface Document for blkio.use_hierarchy interface. Signed-off-by: Gui Jianfeng <guijianfeng@...fujitsu.com> --- Documentation/cgroups/blkio-controller.txt | 81 +++++++++++++++++++++------- 1 files changed, 62 insertions(+), 19 deletions(-) diff --git a/Documentation/cgroups/blkio-controller.txt b/Documentation/cgroups/blkio-controller.txt index 4ed7b5c..24399f4 100644 --- a/Documentation/cgroups/blkio-controller.txt +++ b/Documentation/cgroups/blkio-controller.txt @@ -91,30 +91,62 @@ Throttling/Upper Limit policy 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. +- Cgroup interface allows creation of hierarchical cgroups. Currently, + internally IO policies are able to treat them as flat hierarchy or + hierarchical hierarchy. Both hierarchical bandwidth division and flat + bandwidth division are supported. "blkio.use_hierarchy" can be used to + switch between flat mode and hierarchical mode. - 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. + Note: Currently, "blkio.use_hierarchy" only effects proportional bandwidth + division. For Throttling logic, it still continues to treat everything as flat. - root - / \ - test1 test2 - | - test3 + Consider the following CGroup hierarchy: - CFQ and throttling will practically treat all groups at same level. + Root + / | \ + Grp1 Grp2 tsk1 + / \ + Grp3 tsk2 - pivot - / | \ \ - root test1 test2 test3 + If blkio.use_hierarchy is disabled in all CGroups, CFQ will practically treat all groups + at the same level. - 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. + Pivot tree + / | | \ + Root Grp1 Grp2 Grp3 + / | + tsk1 tsk2 + + If blkio.use_hierarchy is enabled in Root group, then all children will inherit it, thus + all children group have use_hierarchy=1 set automatically and looks as follows. + + Pivot tree + | + Root + / | \ + Grp1 Grp2 tsk1 + / \ + Grp3 tsk2 + + If blkio.use_hierarchy is enabled in Grp1 and Grp3, CFQ will treat groups and tasks as the + same view in CGroup hierarchy, it looks as follows. + + + Pivot tree + / | \ + Root Grp1 Grp2 + / / \ + tsk1 Grp3 tsk2 + + Root, Grp1 and Grp2 are treated at the same level under Pivot tree. tsk1 stays under Root. + Grp3 and tsk2 are treated at the same level under Grp1. Below is the mapping between + task io priority and io weight: + + prio 0 1 2 3 4 5 6 7 + weight 1000 868 740 612 484 356 228 100 + + Note: Regardless of the use_hierarchy setting in Root group, Root group is always put onto + Pivot tree. Various user visible config options =================================== @@ -169,6 +201,17 @@ Proportional weight policy files dev weight 8:16 300 +- blkio.use_hierarchy + - Switch between hierarchical mode and flat mode as stated above. + blkio.use_hierarchy == 1 means hierarchical mode is enabled. + blkio.use_hierarchy == 0 means flat mode is enabled. + You can set this interface only if there isn't any child CGroup under + this CGroup. If one CGroup's blkio.use_hierarchy is set, the created + children will inherit it. it's not allowed to unset it in children. + The default mode in Root CGroup is flat. + blkio.use_hierarchy only works for proportional bandwidth division + as of today and doesn't have any effect on throttling logic. + - blkio.time - disk time allocated to cgroup per device in milliseconds. First two fields specify the major and minor number of the device and -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists