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authorWaiman Long <longman@redhat.com>2019-04-06 04:39:14 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2019-04-06 05:02:31 +0300
commitbe87ab0afd680ac35486d16c0963c56d9be1d8a0 (patch)
tree228934ed65cbf0fb3e1c9fc50151d78742ad02ac
parentc6f3c5ee40c10bb65725047a220570f718507001 (diff)
downloadlinux-be87ab0afd680ac35486d16c0963c56d9be1d8a0.tar.xz
psi: clarify the units used in pressure files
The output of the PSI files show a bunch of numbers with no unit. The psi.txt documentation file also does not indicate what units are used. One can only find out by looking at the source code. The units are percentage for the averages and useconds for the total. Make the information easier to find by documenting the units in psi.txt. Link: http://lkml.kernel.org/r/20190402193810.3450-1-longman@redhat.com Signed-off-by: Waiman Long <longman@redhat.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org> Cc: Tejun Heo <tj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--Documentation/accounting/psi.txt12
1 files changed, 6 insertions, 6 deletions
diff --git a/Documentation/accounting/psi.txt b/Documentation/accounting/psi.txt
index b8ca28b60215..7e71c9c1d8e9 100644
--- a/Documentation/accounting/psi.txt
+++ b/Documentation/accounting/psi.txt
@@ -56,12 +56,12 @@ situation from a state where some tasks are stalled but the CPU is
still doing productive work. As such, time spent in this subset of the
stall state is tracked separately and exported in the "full" averages.
-The ratios are tracked as recent trends over ten, sixty, and three
-hundred second windows, which gives insight into short term events as
-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.
+The ratios (in %) are tracked as recent trends over ten, sixty, and
+three hundred second windows, which gives insight into short term events
+as well as medium and long term trends. The total absolute stall time
+(in us) 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
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