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

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

[Pavankumar Kondeti]

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@codeaurora.org>
---
 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);
-- 
Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.

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

[Pavan Kondeti]

Hi Rafael/Thomas,

On Mon, Jun 3, 2019 at 10:03 AM Pavankumar Kondeti
<pkondeti@codeaurora.org> wrote:
>
> 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.
>

Please let me know if you have any comments on this patch.

Thanks,
Pavan

-- 
Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a
Linux Foundation Collaborative Project