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Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/accounting/cgroupstats.txt | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/Documentation/accounting/cgroupstats.txt b/Documentation/accounting/cgroupstats.txt new file mode 100644 index 000000000000..eda40fd39cad --- /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 |