On Mon, Apr 04, 2016 at 12:27:45PM +0200, Anna-Maria Gleixner wrote:
> Since commit 1cf4f629d9d2 ("cpu/hotplug: Move online calls to
> hotplugged cpu") it is ensured that callbacks of CPU_ONLINE and
> CPU_DOWN_PREPARE are processed on the hotplugged CPU. Due to this SMP
> function calls are no longer required.
>
> Replace smp_call_function_single() with a direct call of
> setup_pmc_cpu(). To keep the calling convention, interrupts are
> explicitely disabled around the call.
>
> Cc: Martin Schwidefsky <[email protected]>
> Cc: Heiko Carstens <[email protected]>
> Cc: [email protected]
> Signed-off-by: Anna-Maria Gleixner <[email protected]>
> ---
> arch/s390/kernel/perf_cpum_cf.c | 9 ++++++---
> 1 file changed, 6 insertions(+), 3 deletions(-)
>
> --- a/arch/s390/kernel/perf_cpum_cf.c
> +++ b/arch/s390/kernel/perf_cpum_cf.c
> @@ -665,18 +665,21 @@ static struct pmu cpumf_pmu = {
> static int cpumf_pmu_notifier(struct notifier_block *self, unsigned long
> action,
> void *hcpu)
> {
> - unsigned int cpu = (long) hcpu;
> int flags;
>
> 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);
> + local_irq_disable();
> + setup_pmc_cpu(&flags);
> + local_irq_enable();
> break;
Same issue about CPU_DOWN_FAILED here.
