[PATCH 5/5] sched/isolation: Document "nohz_offload" flag

From: Frederic Weisbecker
Date: Thu Dec 21 2017 - 12:15:50 EST

Document the interface to offload the 1Hz scheduler tick in full
dynticks mode. Also improve the comment about the existing "nohz" flag
in order to differentiate its behaviour.

Signed-off-by: Frederic Weisbecker <frederic@xxxxxxxxxx>
Cc: Chris Metcalf <cmetcalf@xxxxxxxxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxx>
Cc: Luiz Capitulino <lcapitulino@xxxxxxxxxx>
Cc: Mike Galbraith <efault@xxxxxx>
Cc: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Wanpeng Li <kernellwp@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Documentation/admin-guide/kernel-parameters.txt | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 1683107..fcc5fd9 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1745,7 +1745,12 @@
specified in the flag list (default: domain):

- Disable the tick when a single task runs.
+ Disable the tick when a single task runs. A residual 1Hz
+ tick remains to maintain scheduler stats alive.
+ nohz_offload
+ Like nohz but the residual 1Hz tick is offloaded to
+ housekeeping CPUs, leaving the CPU free of any tick if
+ nothing else requests it.
Isolate from the general SMP balancing and scheduling
algorithms. Note that performing domain isolation this way