From a66d955e910ab0e598d7a7450cbe6139f52befe7 Mon Sep 17 00:00:00 2001 From: Pavankumar Kondeti Date: Mon, 3 Jun 2019 10:01:03 +0530 Subject: [PATCH] cpu/hotplug: Abort disabling secondary CPUs if wakeup is pending When "deep" suspend is enabled, all CPUs except the primary CPU are frozen via CPU hotplug one by one. After all secondary CPUs are unplugged the wakeup pending condition is evaluated and if pending the suspend operation is aborted and the secondary CPUs are brought up again. CPU hotplug is a slow operation, so it makes sense to check for wakeup pending in the freezer loop before bringing down the next CPU. This improves the system suspend abort latency significantly. [ tglx: Massaged changelog and improved printk message ] Signed-off-by: Pavankumar Kondeti Signed-off-by: Thomas Gleixner Cc: "Rafael J. Wysocki" Cc: Len Brown Cc: Pavel Machek Cc: Josh Poimboeuf Cc: Peter Zijlstra Cc: Konrad Rzeszutek Wilk Cc: iri Kosina Cc: Mukesh Ojha Cc: linux-pm@vger.kernel.org Link: https://lkml.kernel.org/r/1559536263-16472-1-git-send-email-pkondeti@codeaurora.org --- kernel/cpu.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/kernel/cpu.c b/kernel/cpu.c index be82cbc11a8a..0778249cd49d 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("Wakeup pending. Abort CPU freeze\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);