This option, similar to NO_HZ_FULL_ALL, simplifies configuring
a system to boot by default with all cores except the boot core
running in task isolation mode.
Signed-off-by: Chris Metcalf <cmetcalf@xxxxxxxxxxxx>
---
init/Kconfig | 10 ++++++++++
kernel/isolation.c | 6 ++++++
2 files changed, 16 insertions(+)
diff --git a/init/Kconfig b/init/Kconfig
index a95a35a31b46..a9b9c7635de2 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -813,6 +813,16 @@ config TASK_ISOLATION
You should say "N" unless you are intending to run a
high-performance userspace driver or similar task.
+config TASK_ISOLATION_ALL
+ bool "Provide task isolation on all CPUs by default (except CPU 0)"
+ depends on TASK_ISOLATION
+ help
+ If the user doesn't pass the task_isolation boot option to
+ define the range of task isolation CPUs, consider that all
+ CPUs in the system are task isolation by default.
+ Note the boot CPU will still be kept outside the range to
+ handle timekeeping duty, etc.
+
config BUILD_BIN2C
bool
default n
diff --git a/kernel/isolation.c b/kernel/isolation.c
index be7e95192e76..3dbb01ac503f 100644
--- a/kernel/isolation.c
+++ b/kernel/isolation.c
@@ -43,8 +43,14 @@ int __init task_isolation_init(void)
{
/* For offstack cpumask, ensure we allocate an empty cpumask early. */
if (!saw_boot_arg) {
+#ifdef CONFIG_TASK_ISOLATION_ALL
+ alloc_cpumask_var(&task_isolation_map, GFP_KERNEL);
+ cpumask_copy(task_isolation_map, cpu_possible_mask);
+ cpumask_clear_cpu(smp_processor_id(), task_isolation_map);
+#else
zalloc_cpumask_var(&task_isolation_map, GFP_KERNEL);
return 0;
+#endif
}
/*
--
2.7.2
--
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