[PATCH] cpu/hotplug: Abort disabling secondary CPUs if wakeup is pending

From: Pavankumar Kondeti
Date: Mon Jun 03 2019 - 00:35:00 EST


When "deep" suspend is enabled, all CPUs except the primary CPU
are hotplugged out. Since CPU hotplug is a costly operation,
check if we have to abort the suspend in between each CPU
hotplug. This would improve the system suspend abort latency
upon detecting a wakeup condition.

Signed-off-by: Pavankumar Kondeti <pkondeti@xxxxxxxxxxxxxx>
---
kernel/cpu.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/kernel/cpu.c b/kernel/cpu.c
index f2ef104..784b33d 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -1221,6 +1221,13 @@ int freeze_secondary_cpus(int primary)
for_each_online_cpu(cpu) {
if (cpu == primary)
continue;
+
+ if (pm_wakeup_pending()) {
+ pr_info("Aborting disabling non-boot CPUs..\n");
+ error = -EBUSY;
+ break;
+ }
+
trace_suspend_resume(TPS("CPU_OFF"), cpu, true);
error = _cpu_down(cpu, 1, CPUHP_OFFLINE);
trace_suspend_resume(TPS("CPU_OFF"), cpu, false);
--
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