* [PATCH 0/2] s390: Hotplug notifier transitions
@ 2016-03-11 10:52 Anna-Maria Gleixner
2016-03-11 10:52 ` [PATCH 1/2] s390/cpum_cf: Fix missing cpu hotplug notifier transition Anna-Maria Gleixner
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Anna-Maria Gleixner @ 2016-03-11 10:52 UTC (permalink / raw)
To: linux-kernel; +Cc: rt, Martin Schwidefsky, Heiko Carstens, linux-s390
The following patches fix missing error handling of hotplug notifier
transitions.
Thanks,
Anna-Maria
---
perf_cpum_cf.c | 1 +
perf_cpum_sf.c | 2 +-
2 files changed, 2 insertions(+), 1 deletion(-)
^ permalink raw reply [flat|nested] 6+ messages in thread* [PATCH 1/2] s390/cpum_cf: Fix missing cpu hotplug notifier transition 2016-03-11 10:52 [PATCH 0/2] s390: Hotplug notifier transitions Anna-Maria Gleixner @ 2016-03-11 10:52 ` Anna-Maria Gleixner 2016-03-11 10:52 ` [PATCH 2/2] s390/cpum_sf: Fix cpu hotplug notifier transitions Anna-Maria Gleixner 2016-03-14 15:47 ` [PATCH 0/2] s390: Hotplug " Heiko Carstens 2 siblings, 0 replies; 6+ messages in thread From: Anna-Maria Gleixner @ 2016-03-11 10:52 UTC (permalink / raw) To: linux-kernel Cc: rt, Martin Schwidefsky, Heiko Carstens, linux-s390, Anna-Maria Gleixner 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. Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux-s390@vger.kernel.org Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de> --- arch/s390/kernel/perf_cpum_cf.c | 1 + 1 file changed, 1 insertion(+) --- 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 not 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; ^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH 2/2] s390/cpum_sf: Fix cpu hotplug notifier transitions 2016-03-11 10:52 [PATCH 0/2] s390: Hotplug notifier transitions Anna-Maria Gleixner 2016-03-11 10:52 ` [PATCH 1/2] s390/cpum_cf: Fix missing cpu hotplug notifier transition Anna-Maria Gleixner @ 2016-03-11 10:52 ` Anna-Maria Gleixner 2016-03-14 8:51 ` Heiko Carstens 2016-03-14 15:47 ` [PATCH 0/2] s390: Hotplug " Heiko Carstens 2 siblings, 1 reply; 6+ messages in thread From: Anna-Maria Gleixner @ 2016-03-11 10:52 UTC (permalink / raw) To: linux-kernel Cc: rt, Martin Schwidefsky, Heiko Carstens, linux-s390, Anna-Maria Gleixner 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. Furthermore the CPU_ONLINE_FROZEN case will never be processed because of masking the switch expression with CPU_TASKS_FROZEN. Add handling for CPU_DOWN_FAILED transition to setup the PMC of the CPU. Remove CPU_ONLINE_FROZEN case. Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux-s390@vger.kernel.org Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de> --- arch/s390/kernel/perf_cpum_sf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/s390/kernel/perf_cpum_sf.c +++ b/arch/s390/kernel/perf_cpum_sf.c @@ -1518,7 +1518,7 @@ static int cpumf_pmu_notifier(struct not switch (action & ~CPU_TASKS_FROZEN) { case CPU_ONLINE: - case CPU_ONLINE_FROZEN: + case CPU_DOWN_FAILED: flags = PMC_INIT; smp_call_function_single(cpu, setup_pmc_cpu, &flags, 1); break; ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 2/2] s390/cpum_sf: Fix cpu hotplug notifier transitions 2016-03-11 10:52 ` [PATCH 2/2] s390/cpum_sf: Fix cpu hotplug notifier transitions Anna-Maria Gleixner @ 2016-03-14 8:51 ` Heiko Carstens 2016-03-14 14:44 ` Hendrik Brueckner 0 siblings, 1 reply; 6+ messages in thread From: Heiko Carstens @ 2016-03-14 8:51 UTC (permalink / raw) To: Anna-Maria Gleixner, Hendrik Brueckner Cc: linux-kernel, rt, Martin Schwidefsky, linux-s390 On Fri, Mar 11, 2016 at 11:52:38AM +0100, Anna-Maria Gleixner wrote: > 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. Furthermore the CPU_ONLINE_FROZEN case > will never be processed because of masking the switch expression with > CPU_TASKS_FROZEN. > > Add handling for CPU_DOWN_FAILED transition to setup the PMC of the > CPU. Remove CPU_ONLINE_FROZEN case. > > Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> > Cc: Heiko Carstens <heiko.carstens@de.ibm.com> > Cc: linux-s390@vger.kernel.org > Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de> > --- > arch/s390/kernel/perf_cpum_sf.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > --- a/arch/s390/kernel/perf_cpum_sf.c > +++ b/arch/s390/kernel/perf_cpum_sf.c > @@ -1518,7 +1518,7 @@ static int cpumf_pmu_notifier(struct not > > switch (action & ~CPU_TASKS_FROZEN) { > case CPU_ONLINE: > - case CPU_ONLINE_FROZEN: > + case CPU_DOWN_FAILED: > flags = PMC_INIT; > smp_call_function_single(cpu, setup_pmc_cpu, &flags, 1); > break; This is a bit odd, but independent from your patch: setup_pmc_cpu() will only deallocate buffers but not allocate them. Looking at the code a bit further this seems to imply that sampling will not work on cpus that were added later. Hendrik, could you please have a look? ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 2/2] s390/cpum_sf: Fix cpu hotplug notifier transitions 2016-03-14 8:51 ` Heiko Carstens @ 2016-03-14 14:44 ` Hendrik Brueckner 0 siblings, 0 replies; 6+ messages in thread From: Hendrik Brueckner @ 2016-03-14 14:44 UTC (permalink / raw) To: Heiko Carstens Cc: Anna-Maria Gleixner, Hendrik Brueckner, linux-kernel, rt, Martin Schwidefsky, linux-s390 On Mon, Mar 14, 2016 at 09:51:50AM +0100, Heiko Carstens wrote: > On Fri, Mar 11, 2016 at 11:52:38AM +0100, Anna-Maria Gleixner wrote: > > 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. Furthermore the CPU_ONLINE_FROZEN case > > will never be processed because of masking the switch expression with > > CPU_TASKS_FROZEN. > > > > Add handling for CPU_DOWN_FAILED transition to setup the PMC of the > > CPU. Remove CPU_ONLINE_FROZEN case. > > > > Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> > > Cc: Heiko Carstens <heiko.carstens@de.ibm.com> > > Cc: linux-s390@vger.kernel.org > > Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de> > > --- > > arch/s390/kernel/perf_cpum_sf.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > --- a/arch/s390/kernel/perf_cpum_sf.c > > +++ b/arch/s390/kernel/perf_cpum_sf.c > > @@ -1518,7 +1518,7 @@ static int cpumf_pmu_notifier(struct not > > > > switch (action & ~CPU_TASKS_FROZEN) { > > case CPU_ONLINE: > > - case CPU_ONLINE_FROZEN: > > + case CPU_DOWN_FAILED: The change looks ok for me. Acked-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> > > flags = PMC_INIT; > > smp_call_function_single(cpu, setup_pmc_cpu, &flags, 1); > > break; > > This is a bit odd, but independent from your patch: setup_pmc_cpu() will > only deallocate buffers but not allocate them. That's right. Allocation is done when an perf event is about to be scheduled on a CPU. > > Looking at the code a bit further this seems to imply that sampling will > not work on cpus that were added later. That might be a problem for task-based perf events. I will have a closer look into that issue. Many thanks. Kind regards, Hendrik ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 0/2] s390: Hotplug notifier transitions 2016-03-11 10:52 [PATCH 0/2] s390: Hotplug notifier transitions Anna-Maria Gleixner 2016-03-11 10:52 ` [PATCH 1/2] s390/cpum_cf: Fix missing cpu hotplug notifier transition Anna-Maria Gleixner 2016-03-11 10:52 ` [PATCH 2/2] s390/cpum_sf: Fix cpu hotplug notifier transitions Anna-Maria Gleixner @ 2016-03-14 15:47 ` Heiko Carstens 2 siblings, 0 replies; 6+ messages in thread From: Heiko Carstens @ 2016-03-14 15:47 UTC (permalink / raw) To: Anna-Maria Gleixner; +Cc: linux-kernel, rt, Martin Schwidefsky, linux-s390 On Fri, Mar 11, 2016 at 11:52:36AM +0100, Anna-Maria Gleixner wrote: > The following patches fix missing error handling of hotplug notifier > transitions. > > Thanks, > Anna-Maria > > --- > perf_cpum_cf.c | 1 + > perf_cpum_sf.c | 2 +- > 2 files changed, 2 insertions(+), 1 deletion(-) Applied, thanks! ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2016-03-14 15:48 UTC | newest] Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2016-03-11 10:52 [PATCH 0/2] s390: Hotplug notifier transitions Anna-Maria Gleixner 2016-03-11 10:52 ` [PATCH 1/2] s390/cpum_cf: Fix missing cpu hotplug notifier transition Anna-Maria Gleixner 2016-03-11 10:52 ` [PATCH 2/2] s390/cpum_sf: Fix cpu hotplug notifier transitions Anna-Maria Gleixner 2016-03-14 8:51 ` Heiko Carstens 2016-03-14 14:44 ` Hendrik Brueckner 2016-03-14 15:47 ` [PATCH 0/2] s390: Hotplug " Heiko Carstens
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for NNTP newsgroup(s).