Linus,
please pull the latest sched-urgent-for-linus git tree from:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git
sched-urgent-for-linus
Three patches addressing the fallout of the CPU_ISOLATION changes
especially with NO_HZ_FULL plus documentation of boot parameter dependency.
Thanks,
tglx
------------------>
Frederic Weisbecker (2):
sched/isolation: Enable CONFIG_CPU_ISOLATION=y by default
sched/isolation: Document boot parameters dependency on
CONFIG_CPU_ISOLATION=y
Paul E. McKenney (1):
sched/isolation: Make CONFIG_NO_HZ_FULL select CONFIG_CPU_ISOLATION
Documentation/admin-guide/kernel-parameters.rst | 1 +
Documentation/admin-guide/kernel-parameters.txt | 4 ++--
init/Kconfig | 6 +++++-
kernel/time/Kconfig | 1 +
4 files changed, 9 insertions(+), 3 deletions(-)
diff --git a/Documentation/admin-guide/kernel-parameters.rst
b/Documentation/admin-guide/kernel-parameters.rst
index b2598cc9834c..7242cbda15dd 100644
--- a/Documentation/admin-guide/kernel-parameters.rst
+++ b/Documentation/admin-guide/kernel-parameters.rst
@@ -109,6 +109,7 @@ parameter is applicable::
IPV6 IPv6 support is enabled.
ISAPNP ISA PnP code is enabled.
ISDN Appropriate ISDN support is enabled.
+ ISOL CPU Isolation is enabled.
JOY Appropriate joystick support is enabled.
KGDB Kernel debugger support is enabled.
KVM Kernel Virtual Machine support is enabled.
diff --git a/Documentation/admin-guide/kernel-parameters.txt
b/Documentation/admin-guide/kernel-parameters.txt
index 6571fbfdb2a1..168310707ec2 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1737,7 +1737,7 @@
isapnp= [ISAPNP]
Format: <RDP>,<reset>,<pci_scan>,<verbosity>
- isolcpus= [KNL,SMP] Isolate a given set of CPUs from disturbance.
+ isolcpus= [KNL,SMP,ISOL] Isolate a given set of CPUs from
disturbance.
[Deprecated - use cpusets instead]
Format: [flag-list,]<cpu-list>
@@ -2662,7 +2662,7 @@
Valid arguments: on, off
Default: on
- nohz_full= [KNL,BOOT]
+ nohz_full= [KNL,BOOT,SMP,ISOL]
The argument is a cpu list, as described above.
In kernels built with CONFIG_NO_HZ_FULL=y, set
the specified list of CPUs whose tick will be stopped
diff --git a/init/Kconfig b/init/Kconfig
index 2934249fba46..690a381adee0 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -461,10 +461,14 @@ endmenu # "CPU/Task time and stats accounting"
config CPU_ISOLATION
bool "CPU isolation"
+ default y
help
Make sure that CPUs running critical tasks are not disturbed by
any source of "noise" such as unbound workqueues, timers, kthreads...
- Unbound jobs get offloaded to housekeeping CPUs.
+ Unbound jobs get offloaded to housekeeping CPUs. This is driven by
+ the "isolcpus=" boot parameter.
+
+ Say Y if unsure.
source "kernel/rcu/Kconfig"
diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig
index e776fc8cc1df..f6b5f19223d6 100644
--- a/kernel/time/Kconfig
+++ b/kernel/time/Kconfig
@@ -95,6 +95,7 @@ config NO_HZ_FULL
select RCU_NOCB_CPU
select VIRT_CPU_ACCOUNTING_GEN
select IRQ_WORK
+ select CPU_ISOLATION
help
Adaptively try to shutdown the tick whenever possible, even when
the CPU is running tasks. Typically this requires running a single
