summaryrefslogtreecommitdiffstats
path: root/Documentation/accounting
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/accounting')
-rw-r--r--Documentation/accounting/cgroupstats.txt27
1 files changed, 27 insertions, 0 deletions
diff --git a/Documentation/accounting/cgroupstats.txt b/Documentation/accounting/cgroupstats.txt
new file mode 100644
index 0000000..eda40fd
--- /dev/null
+++ b/Documentation/accounting/cgroupstats.txt
@@ -0,0 +1,27 @@
+Control Groupstats is inspired by the discussion at
+http://lkml.org/lkml/2007/4/11/187 and implements per cgroup statistics as
+suggested by Andrew Morton in http://lkml.org/lkml/2007/4/11/263.
+
+Per cgroup statistics infrastructure re-uses code from the taskstats
+interface. A new set of cgroup operations are registered with commands
+and attributes specific to cgroups. It should be very easy to
+extend per cgroup statistics, by adding members to the cgroupstats
+structure.
+
+The current model for cgroupstats is a pull, a push model (to post
+statistics on interesting events), should be very easy to add. Currently
+user space requests for statistics by passing the cgroup path.
+Statistics about the state of all the tasks in the cgroup is returned to
+user space.
+
+NOTE: We currently rely on delay accounting for extracting information
+about tasks blocked on I/O. If CONFIG_TASK_DELAY_ACCT is disabled, this
+information will not be available.
+
+To extract cgroup statistics a utility very similar to getdelays.c
+has been developed, the sample output of the utility is shown below
+
+~/balbir/cgroupstats # ./getdelays -C "/cgroup/a"
+sleeping 1, blocked 0, running 1, stopped 0, uninterruptible 0
+~/balbir/cgroupstats # ./getdelays -C "/cgroup"
+sleeping 155, blocked 0, running 1, stopped 0, uninterruptible 2
OpenPOWER on IntegriCloud