path: root/Documentation/accounting
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authorJohannes Weiner <>2018-10-26 15:06:31 -0700
committerLinus Torvalds <>2018-10-26 16:26:32 -0700
commit2ce7135adc9ad081aa3c49744144376ac74fea60 (patch)
tree991e01428febe956b2b9a7f94aa835f20c754f2e /Documentation/accounting
parenteb414681d5a07d28d2ff90dc05f69ec6b232ebd2 (diff)
psi: cgroup support
On a system that executes multiple cgrouped jobs and independent workloads, we don't just care about the health of the overall system, but also that of individual jobs, so that we can ensure individual job health, fairness between jobs, or prioritize some jobs over others. This patch implements pressure stall tracking for cgroups. In kernels with CONFIG_PSI=y, cgroup2 groups will have cpu.pressure, memory.pressure, and io.pressure files that track aggregate pressure stall times for only the tasks inside the cgroup. Link: Signed-off-by: Johannes Weiner <> Acked-by: Tejun Heo <> Acked-by: Peter Zijlstra (Intel) <> Tested-by: Daniel Drake <> Tested-by: Suren Baghdasaryan <> Cc: Christopher Lameter <> Cc: Ingo Molnar <> Cc: Johannes Weiner <> Cc: Mike Galbraith <> Cc: Peter Enderborg <> Cc: Randy Dunlap <> Cc: Shakeel Butt <> Cc: Vinayak Menon <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
Diffstat (limited to 'Documentation/accounting')
1 files changed, 9 insertions, 0 deletions
diff --git a/Documentation/accounting/psi.txt b/Documentation/accounting/psi.txt
index 3753a82f1cf5..b8ca28b60215 100644
--- a/Documentation/accounting/psi.txt
+++ b/Documentation/accounting/psi.txt
@@ -62,3 +62,12 @@ well as medium and long term trends. The total absolute stall time is
tracked and exported as well, to allow detection of latency spikes
which wouldn't necessarily make a dent in the time averages, or to
average trends over custom time frames.
+Cgroup2 interface
+In a system with a CONFIG_CGROUP=y kernel and the cgroup2 filesystem
+mounted, pressure stall information is also tracked for tasks grouped
+into cgroups. Each subdirectory in the cgroupfs mountpoint contains
+cpu.pressure, memory.pressure, and io.pressure files; the format is
+the same as the /proc/pressure/ files.