[PATCH 4.14 039/104] cpu/hotplug: Split do_cpu_down()

From: Greg Kroah-Hartman
Date: Tue Aug 14 2018 - 13:37:24 EST


4.14-stable review patch. If anyone has any objections, please let me know.

------------------

From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

commit cc1fe215e1efa406b03aa4389e6269b61342dec5 upstream

Split out the inner workings of do_cpu_down() to allow reuse of that
function for the upcoming SMT disabling mechanism.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Acked-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
kernel/cpu.c | 17 ++++++++---------
1 file changed, 8 insertions(+), 9 deletions(-)

--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -910,20 +910,19 @@ out:
return ret;
}

+static int cpu_down_maps_locked(unsigned int cpu, enum cpuhp_state target)
+{
+ if (cpu_hotplug_disabled)
+ return -EBUSY;
+ return _cpu_down(cpu, 0, target);
+}
+
static int do_cpu_down(unsigned int cpu, enum cpuhp_state target)
{
int err;

cpu_maps_update_begin();
-
- if (cpu_hotplug_disabled) {
- err = -EBUSY;
- goto out;
- }
-
- err = _cpu_down(cpu, 0, target);
-
-out:
+ err = cpu_down_maps_locked(cpu, target);
cpu_maps_update_done();
return err;
}