Re: [PATCH] s390/cpum_sf: Remove superfluous SMP function call

2016-04-05 Thread Sebastian Andrzej Siewior
On 04/05/2016 02:11 PM, Heiko Carstens wrote: > I think there is more broken: if I willingly let __cpu_disable() fail and > try to offline e.g. cpu 2 for the second time chcpu will never return. > Plus the console contains several "NOHZ: local_softirq_pending 01" > messages. … > > All of this

Re: [PATCH] s390/cpum_sf: Remove superfluous SMP function call

2016-04-05 Thread Sebastian Andrzej Siewior
On 04/05/2016 02:11 PM, Heiko Carstens wrote: > I think there is more broken: if I willingly let __cpu_disable() fail and > try to offline e.g. cpu 2 for the second time chcpu will never return. > Plus the console contains several "NOHZ: local_softirq_pending 01" > messages. … > > All of this

Re: [PREEMPT-RT] [PATCH] s390/cpum_sf: Remove superfluous SMP function call

2016-04-05 Thread Heiko Carstens
On Tue, Apr 05, 2016 at 01:57:42PM +0200, Sebastian Andrzej Siewior wrote: > On 04/05/2016 01:51 PM, rcoch...@linutronix.de wrote: > > On Tue, Apr 05, 2016 at 01:36:38PM +0200, Heiko Carstens wrote: > >> On Tue, Apr 05, 2016 at 01:23:36PM +0200, Heiko Carstens wrote: > >>> Subsequently, in this

Re: [PREEMPT-RT] [PATCH] s390/cpum_sf: Remove superfluous SMP function call

2016-04-05 Thread Heiko Carstens
On Tue, Apr 05, 2016 at 01:57:42PM +0200, Sebastian Andrzej Siewior wrote: > On 04/05/2016 01:51 PM, rcoch...@linutronix.de wrote: > > On Tue, Apr 05, 2016 at 01:36:38PM +0200, Heiko Carstens wrote: > >> On Tue, Apr 05, 2016 at 01:23:36PM +0200, Heiko Carstens wrote: > >>> Subsequently, in this

Re: [PREEMPT-RT] [PATCH] s390/cpum_sf: Remove superfluous SMP function call

2016-04-05 Thread Sebastian Andrzej Siewior
On 04/05/2016 01:51 PM, rcoch...@linutronix.de wrote: > On Tue, Apr 05, 2016 at 01:36:38PM +0200, Heiko Carstens wrote: >> On Tue, Apr 05, 2016 at 01:23:36PM +0200, Heiko Carstens wrote: >>> Subsequently, in this case, the setup_pmc_cpu() call will be executed on >>> the wrong cpu. >> >> .. or to

Re: [PREEMPT-RT] [PATCH] s390/cpum_sf: Remove superfluous SMP function call

2016-04-05 Thread Sebastian Andrzej Siewior
On 04/05/2016 01:51 PM, rcoch...@linutronix.de wrote: > On Tue, Apr 05, 2016 at 01:36:38PM +0200, Heiko Carstens wrote: >> On Tue, Apr 05, 2016 at 01:23:36PM +0200, Heiko Carstens wrote: >>> Subsequently, in this case, the setup_pmc_cpu() call will be executed on >>> the wrong cpu. >> >> .. or to

Re: [PREEMPT-RT] [PATCH] s390/cpum_sf: Remove superfluous SMP function call

2016-04-05 Thread Heiko Carstens
On Tue, Apr 05, 2016 at 01:51:29PM +0200, rcoch...@linutronix.de wrote: > On Tue, Apr 05, 2016 at 01:36:38PM +0200, Heiko Carstens wrote: > > On Tue, Apr 05, 2016 at 01:23:36PM +0200, Heiko Carstens wrote: > > > Subsequently, in this case, the setup_pmc_cpu() call will be executed on > > > the

Re: [PREEMPT-RT] [PATCH] s390/cpum_sf: Remove superfluous SMP function call

2016-04-05 Thread Heiko Carstens
On Tue, Apr 05, 2016 at 01:51:29PM +0200, rcoch...@linutronix.de wrote: > On Tue, Apr 05, 2016 at 01:36:38PM +0200, Heiko Carstens wrote: > > On Tue, Apr 05, 2016 at 01:23:36PM +0200, Heiko Carstens wrote: > > > Subsequently, in this case, the setup_pmc_cpu() call will be executed on > > > the

Re: [PREEMPT-RT] [PATCH] s390/cpum_sf: Remove superfluous SMP function call

2016-04-05 Thread rcochran
On Tue, Apr 05, 2016 at 01:36:38PM +0200, Heiko Carstens wrote: > On Tue, Apr 05, 2016 at 01:23:36PM +0200, Heiko Carstens wrote: > > Subsequently, in this case, the setup_pmc_cpu() call will be executed on > > the wrong cpu. > > .. or to illustrate this behaviour: the following patch (white

Re: [PREEMPT-RT] [PATCH] s390/cpum_sf: Remove superfluous SMP function call

2016-04-05 Thread rcochran
On Tue, Apr 05, 2016 at 01:36:38PM +0200, Heiko Carstens wrote: > On Tue, Apr 05, 2016 at 01:23:36PM +0200, Heiko Carstens wrote: > > Subsequently, in this case, the setup_pmc_cpu() call will be executed on > > the wrong cpu. > > .. or to illustrate this behaviour: the following patch (white

Re: [PREEMPT-RT] [PATCH] s390/cpum_sf: Remove superfluous SMP function call

2016-04-05 Thread Heiko Carstens
On Tue, Apr 05, 2016 at 01:23:36PM +0200, Heiko Carstens wrote: > On Tue, Apr 05, 2016 at 01:13:06PM +0200, Sebastian Andrzej Siewior wrote: > > On 04/05/2016 12:49 PM, Heiko Carstens wrote: > > >> --- a/arch/s390/kernel/perf_cpum_sf.c > > >> +++ b/arch/s390/kernel/perf_cpum_sf.c > > >> @@ -1510,7

Re: [PREEMPT-RT] [PATCH] s390/cpum_sf: Remove superfluous SMP function call

2016-04-05 Thread Heiko Carstens
On Tue, Apr 05, 2016 at 01:23:36PM +0200, Heiko Carstens wrote: > On Tue, Apr 05, 2016 at 01:13:06PM +0200, Sebastian Andrzej Siewior wrote: > > On 04/05/2016 12:49 PM, Heiko Carstens wrote: > > >> --- a/arch/s390/kernel/perf_cpum_sf.c > > >> +++ b/arch/s390/kernel/perf_cpum_sf.c > > >> @@ -1510,7

Re: [PREEMPT-RT] [PATCH] s390/cpum_sf: Remove superfluous SMP function call

2016-04-05 Thread Heiko Carstens
On Tue, Apr 05, 2016 at 01:13:06PM +0200, Sebastian Andrzej Siewior wrote: > On 04/05/2016 12:49 PM, Heiko Carstens wrote: > >> --- a/arch/s390/kernel/perf_cpum_sf.c > >> +++ b/arch/s390/kernel/perf_cpum_sf.c > >> @@ -1510,7 +1510,6 @@ static void cpumf_measurement_alert(stru > >> static int

Re: [PREEMPT-RT] [PATCH] s390/cpum_sf: Remove superfluous SMP function call

2016-04-05 Thread Heiko Carstens
On Tue, Apr 05, 2016 at 01:13:06PM +0200, Sebastian Andrzej Siewior wrote: > On 04/05/2016 12:49 PM, Heiko Carstens wrote: > >> --- a/arch/s390/kernel/perf_cpum_sf.c > >> +++ b/arch/s390/kernel/perf_cpum_sf.c > >> @@ -1510,7 +1510,6 @@ static void cpumf_measurement_alert(stru > >> static int

Re: [PREEMPT-RT] [PATCH] s390/cpum_sf: Remove superfluous SMP function call

2016-04-05 Thread Sebastian Andrzej Siewior
On 04/05/2016 12:49 PM, Heiko Carstens wrote: >> --- a/arch/s390/kernel/perf_cpum_sf.c >> +++ b/arch/s390/kernel/perf_cpum_sf.c >> @@ -1510,7 +1510,6 @@ static void cpumf_measurement_alert(stru >> static int cpumf_pmu_notifier(struct notifier_block *self, >>unsigned

Re: [PREEMPT-RT] [PATCH] s390/cpum_sf: Remove superfluous SMP function call

2016-04-05 Thread Sebastian Andrzej Siewior
On 04/05/2016 12:49 PM, Heiko Carstens wrote: >> --- a/arch/s390/kernel/perf_cpum_sf.c >> +++ b/arch/s390/kernel/perf_cpum_sf.c >> @@ -1510,7 +1510,6 @@ static void cpumf_measurement_alert(stru >> static int cpumf_pmu_notifier(struct notifier_block *self, >>unsigned

Re: [PATCH] s390/cpum_sf: Remove superfluous SMP function call

2016-04-05 Thread Heiko Carstens
On Mon, Apr 04, 2016 at 12:27:20PM +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

Re: [PATCH] s390/cpum_sf: Remove superfluous SMP function call

2016-04-05 Thread Heiko Carstens
On Mon, Apr 04, 2016 at 12:27:20PM +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

[PATCH] s390/cpum_sf: Remove superfluous SMP function call

2016-04-04 Thread Anna-Maria Gleixner
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

[PATCH] s390/cpum_sf: Remove superfluous SMP function call

2016-04-04 Thread Anna-Maria Gleixner
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