[tip:sched/core] sched/isolation: Document the isolcpus= flags

[tip-bot for Frederic Weisbecker]

Commit-ID:  98a06af93784a6ae541e9fc6292ef26177832543
Gitweb:     https://git.kernel.org/tip/98a06af93784a6ae541e9fc6292ef26177832543
Author:     Frederic Weisbecker <frederic@xxxxxxxxxx>
AuthorDate: Fri, 27 Oct 2017 04:42:39 +0200
Committer:  Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Fri, 27 Oct 2017 09:55:32 +0200

sched/isolation: Document the isolcpus= flags

Signed-off-by: Frederic Weisbecker <frederic@xxxxxxxxxx>
Acked-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Chris Metcalf <cmetcalf@xxxxxxxxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
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: Wanpeng Li <kernellwp@xxxxxxxxx>
Link: http://lkml.kernel.org/r/1509072159-31808-13-git-send-email-frederic@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
 Documentation/admin-guide/kernel-parameters.txt | 33 +++++++++++++++----------
 1 file changed, 20 insertions(+), 13 deletions(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 6b99c8b..5853618 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1727,20 +1727,27 @@
 	isapnp=		[ISAPNP]
 			Format: <RDP>,<reset>,<pci_scan>,<verbosity>
 
-	isolcpus=	[KNL,SMP] Isolate CPUs from the general scheduler.
-			The argument is a cpu list, as described above.
+	isolcpus=	[KNL,SMP] Isolate a given set of CPUs from disturbance.
+			Format: [flag-list,]<cpu-list>
+
+			Specify one or more CPUs to isolate from disturbances
+			specified in the flag list (default: domain):
+
+			nohz
+			  Disable the tick when a single task runs.
+			domain
+			  Isolate from the general SMP balancing and scheduling
+			  algorithms. This option is the preferred way to isolate
+			  CPUs from tasks. The alternative -- manually setting the
+			  CPU mask of all tasks in the system, can cause problems
+			  and suboptimal load balancer performance. You can move a
+			  process onto or off an "isolated" CPU via the CPU
+			  affinity syscalls or cpuset. <cpu number> begins at 0
+			  and the maximum value is "number of CPUs in system - 1".
+
+			The format of <cpu-list> is described above.
+
 
-			This option can be used to specify one or more CPUs
-			to isolate from the general SMP balancing and scheduling
-			algorithms. You can move a process onto or off an
-			"isolated" CPU via the CPU affinity syscalls or cpuset.
-			<cpu number> begins at 0 and the maximum value is
-			"number of CPUs in system - 1".
-
-			This option is the preferred way to isolate CPUs. The
-			alternative -- manually setting the CPU mask of all
-			tasks in the system -- can cause problems and
-			suboptimal load balancer performance.
 
 	iucv=		[HW,NET]