On 26 September 2016 at 10:18, Alexander Shishkin
<alexander.shish...@linux.intel.com> wrote:
> Alexander Shishkin <alexander.shish...@linux.intel.com> writes:
>
>> If PMU callbacks are executed in hardirq context, the address filter
>> sync code needs to disable interrupts when taking its spinlock to be
>> consistent with the rest of its users. This may happen if the PMU is
>> used in AUX sampling.
>
> Hi Mathieu,
>
> I've been meaning to CC you on this series and forgot. My concern was
> that on PMUs that run PMIs in hardirq context this patch should be
> required already now. Is this the case for you?
At this time cross triggers haven't been implemented and as such, PMIs
aren't an issue. On the flip side I can see the value of your code
when we get around to do the implementation.
Mathieu
>
>>
>> Signed-off-by: Alexander Shishkin <alexander.shish...@linux.intel.com>
>> ---
>> kernel/events/core.c | 5 +++--
>> 1 file changed, 3 insertions(+), 2 deletions(-)
>>
>> diff --git a/kernel/events/core.c b/kernel/events/core.c
>> index f6582df1c9..047c495c94 100644
>> --- a/kernel/events/core.c
>> +++ b/kernel/events/core.c
>> @@ -2568,16 +2568,17 @@ static int perf_event_stop(struct perf_event *event,
>> int restart)
>> void perf_event_addr_filters_sync(struct perf_event *event)
>> {
>> struct perf_addr_filters_head *ifh = perf_event_addr_filters(event);
>> + unsigned long flags;
>>
>> if (!has_addr_filter(event))
>> return;
>>
>> - raw_spin_lock(&ifh->lock);
>> + raw_spin_lock_irqsave(&ifh->lock, flags);
>> if (event->addr_filters_gen != event->hw.addr_filters_gen) {
>> event->pmu->addr_filters_sync(event);
>> event->hw.addr_filters_gen = event->addr_filters_gen;
>> }
>> - raw_spin_unlock(&ifh->lock);
>> + raw_spin_unlock_irqrestore(&ifh->lock, flags);
>> }
>> EXPORT_SYMBOL_GPL(perf_event_addr_filters_sync);
>>
>> --
>> 2.9.3
