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authorFrederic Weisbecker <frederic@kernel.org>2017-10-27 04:42:34 +0200
committerIngo Molnar <mingo@kernel.org>2017-10-27 09:55:28 +0200
commit5c4991e24c69737bd41fc2737b1e3980abbf73f9 (patch)
tree2f2b4b49af198c6ed206581c3030fb955fb68843
parent204c083a009378dfa751175b5fcddc75988bab6c (diff)
sched/isolation: Split out new CONFIG_CPU_ISOLATION=y config from CONFIG_NO_HZ_FULL
Split the housekeeping config from CONFIG_NO_HZ_FULL. This way we finally separate the isolation code from NOHZ. Although a dependency to CONFIG_NO_HZ_FULL remains for now, while the housekeeping code still deals with NOHZ internals. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Christoph Lameter <cl@linux.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Wanpeng Li <kernellwp@gmail.com> Link: http://lkml.kernel.org/r/1509072159-31808-8-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
-rw-r--r--include/linux/sched/isolation.h6
-rw-r--r--init/Kconfig8
-rw-r--r--kernel/sched/Makefile2
3 files changed, 12 insertions, 4 deletions
diff --git a/include/linux/sched/isolation.h b/include/linux/sched/isolation.h
index ad0f5d986a2e..93ac2367a520 100644
--- a/include/linux/sched/isolation.h
+++ b/include/linux/sched/isolation.h
@@ -5,7 +5,7 @@
#include <linux/init.h>
#include <linux/tick.h>
-#ifdef CONFIG_NO_HZ_FULL
+#ifdef CONFIG_CPU_ISOLATION
DECLARE_STATIC_KEY_FALSE(housekeeping_overriden);
extern int housekeeping_any_cpu(void);
extern const struct cpumask *housekeeping_cpumask(void);
@@ -27,11 +27,11 @@ static inline const struct cpumask *housekeeping_cpumask(void)
static inline void housekeeping_affine(struct task_struct *t) { }
static inline void housekeeping_init(void) { }
-#endif /* CONFIG_NO_HZ_FULL */
+#endif /* CONFIG_CPU_ISOLATION */
static inline bool housekeeping_cpu(int cpu)
{
-#ifdef CONFIG_NO_HZ_FULL
+#ifdef CONFIG_CPU_ISOLATION
if (static_branch_unlikely(&housekeeping_overriden))
return housekeeping_test_cpu(cpu);
#endif
diff --git a/init/Kconfig b/init/Kconfig
index 78cb2461012e..6f52e6f4bd9d 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -472,6 +472,14 @@ config TASK_IO_ACCOUNTING
endmenu # "CPU/Task time and stats accounting"
+config CPU_ISOLATION
+ bool "CPU isolation"
+ depends on NO_HZ_FULL
+ 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.
+
source "kernel/rcu/Kconfig"
config BUILD_BIN2C
diff --git a/kernel/sched/Makefile b/kernel/sched/Makefile
index 871d43d73375..dbe61302c352 100644
--- a/kernel/sched/Makefile
+++ b/kernel/sched/Makefile
@@ -26,4 +26,4 @@ obj-$(CONFIG_CGROUP_CPUACCT) += cpuacct.o
obj-$(CONFIG_CPU_FREQ) += cpufreq.o
obj-$(CONFIG_CPU_FREQ_GOV_SCHEDUTIL) += cpufreq_schedutil.o
obj-$(CONFIG_MEMBARRIER) += membarrier.o
-obj-$(CONFIG_NO_HZ_FULL) += isolation.o
+obj-$(CONFIG_CPU_ISOLATION) += isolation.o