Hi, On Wed, Jul 13, 2016 at 05:16:36PM +0000, Anna-Maria Gleixner wrote: > From: Thomas Gleixner <[email protected]> > > Straight forward conversion w/o bells and whistles. > > Signed-off-by: Thomas Gleixner <[email protected]> > Reviewed-by: Sebastian Andrzej Siewior <[email protected]> > Cc: Linus Torvalds <[email protected]> > Cc: Mark Rutland <[email protected]> > Cc: Peter Zijlstra <[email protected]> > Cc: Will Deacon <[email protected]> > Signed-off-by: Anna-Maria Gleixner <[email protected]> > --- > drivers/perf/arm_pmu.c | 36 +++++++++++++++--------------------- > include/linux/cpuhotplug.h | 1 + > include/linux/perf/arm_pmu.h | 1 - > 3 files changed, 16 insertions(+), 22 deletions(-) > > diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c > index 140436a..ae9fc6c 100644 > --- a/drivers/perf/arm_pmu.c > +++ b/drivers/perf/arm_pmu.c > @@ -691,24 +691,15 @@ static int cpu_pmu_request_irq(struct arm_pmu *cpu_pmu, > irq_handler_t handler) > * UNKNOWN at reset, the PMU must be explicitly reset to avoid reading > * junk values out of them. > */ > -static int cpu_pmu_notify(struct notifier_block *b, unsigned long action, > - void *hcpu) > +static int arm_perf_starting_cpu(unsigned int cpu) > { > - int cpu = (unsigned long)hcpu; > - struct arm_pmu *pmu = container_of(b, struct arm_pmu, hotplug_nb); > - > - if ((action & ~CPU_TASKS_FROZEN) != CPU_STARTING) > - return NOTIFY_DONE; > - > - if (!cpumask_test_cpu(cpu, &pmu->supported_cpus)) > - return NOTIFY_DONE; > - > - if (pmu->reset) > - pmu->reset(pmu); > - else > - return NOTIFY_DONE; > - > - return NOTIFY_OK; > + if (!__oprofile_cpu_pmu) > + return 0; > + if (!cpumask_test_cpu(cpu, &__oprofile_cpu_pmu->supported_cpus)) > + return 0; > + if (__oprofile_cpu_pmu->reset) > + __oprofile_cpu_pmu->reset(__oprofile_cpu_pmu); > + return 0; > }
We may have multiple PMUs (e.g. two in big.LITTLE systems), and __oprofile_cpu_pmu only contains one of these. So this conversion is not correct. We were relying on the notifier list implicitly containing a list of those PMUs. It seems like we need an explicit list here. We keep __oprofile_cpu_pmu around for legacy 32-bit users of OProfile (on non-hetereogeneous systems), and that's all that the variable should be used for. Thanks, Mark.
