From: Anna-Maria Gleixner <anna-maria@linutronix.de>
Date: Fri, 11 Mar 2016 10:52:37 +0000 (+0100)
Subject: s390/cpum_cf: Fix missing cpu hotplug notifier transition
X-Git-Tag: v4.6-rc2~19^2~8
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=a987884295891f18fddf9c76d7d47c9486701560;p=users%2Fwilly%2Flinux.git

s390/cpum_cf: Fix missing cpu hotplug notifier transition

The cpumf_pmu_notfier() hotplug callback lacks handling of the
CPU_DOWN_FAILED case. That means, if CPU_DOWN_PREPARE failes, the PMC
of the CPU is not setup again.

Add handling for CPU_DOWN_FAILED transition to setup the PMC of the
CPU.

Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---

diff --git a/arch/s390/kernel/perf_cpum_cf.c b/arch/s390/kernel/perf_cpum_cf.c
index 58bf4572d457..62f066b5259e 100644
--- a/arch/s390/kernel/perf_cpum_cf.c
+++ b/arch/s390/kernel/perf_cpum_cf.c
@@ -670,6 +670,7 @@ static int cpumf_pmu_notifier(struct notifier_block *self, unsigned long action,
 
 	switch (action & ~CPU_TASKS_FROZEN) {
 	case CPU_ONLINE:
+	case CPU_DOWN_FAILED:
 		flags = PMC_INIT;
 		smp_call_function_single(cpu, setup_pmc_cpu, &flags, 1);
 		break;