32 lines
1.4 KiB
ReStructuredText
32 lines
1.4 KiB
ReStructuredText
==================
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Control Groupstats
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==================
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Control Groupstats is inspired by the discussion at
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https://lore.kernel.org/r/461CF883.2030308@sw.ru and implements per cgroup statistics as
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suggested by Andrew Morton in https://lore.kernel.org/r/20070411114927.1277d7c9.akpm@linux-foundation.org.
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Per cgroup statistics infrastructure re-uses code from the taskstats
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interface. A new set of cgroup operations are registered with commands
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and attributes specific to cgroups. It should be very easy to
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extend per cgroup statistics, by adding members to the cgroupstats
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structure.
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The current model for cgroupstats is a pull, a push model (to post
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statistics on interesting events), should be very easy to add. Currently
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user space requests for statistics by passing the cgroup path.
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Statistics about the state of all the tasks in the cgroup is returned to
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user space.
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NOTE: We currently rely on delay accounting for extracting information
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about tasks blocked on I/O. If CONFIG_TASK_DELAY_ACCT is disabled, this
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information will not be available.
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To extract cgroup statistics a utility very similar to getdelays.c
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has been developed, the sample output of the utility is shown below::
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~/balbir/cgroupstats # ./getdelays -C "/sys/fs/cgroup/a"
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sleeping 1, blocked 0, running 1, stopped 0, uninterruptible 0
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~/balbir/cgroupstats # ./getdelays -C "/sys/fs/cgroup"
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sleeping 155, blocked 0, running 1, stopped 0, uninterruptible 2
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