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

From: Pavankumar Kondeti <pkondeti@codeaurora.org>
To: "Rafael J. Wysocki" <rjw@rjwysocki.net>,
	Len Brown <len.brown@intel.com>, Pavel Machek <pavel@ucw.cz>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@kernel.org>,
	Josh Poimboeuf <jpoimboe@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
	iri Kosina <jkosina@suse.cz>, Mukesh Ojha <mojha@codeaurora.org>,
	linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: Pavankumar Kondeti <pkondeti@codeaurora.org>
Subject: [PATCH] cpu/hotplug: Abort disabling secondary CPUs if wakeup is pending
Date: Mon,  3 Jun 2019 10:01:03 +0530	[thread overview]
Message-ID: <1559536263-16472-1-git-send-email-pkondeti@codeaurora.org> (raw)

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.

