>
> On Thu, Jul 16, 2015 at 09:33:45PM +0100, kan.li...@intel.com wrote:
> > From: Kan Liang <kan.li...@intel.com>
> >
> > Using is_hardware_event to replace !is_software_event to indicate a
> > hardware event.
>
> Why...?
First, the comments of is_software_event is not correct.
0 or !is_software_event is not for a hardware event.
is_hardware_event is for a hardware event.
Also, the following patch make mix core_misc event be part of hw/sw
event, !is_software_event could be either hw event or core_misc event.
We need an accurate definition here.
>
> For an uncore event e, is_hardware_event(e) != !is_software_event(e),
> so this will be a change of behaviour...
Uncore event cannot be part of hw/sw event group. So it doesn't change the
behavior.
>
> >
> > Signed-off-by: Kan Liang <kan.li...@intel.com>
> > ---
> > include/linux/perf_event.h | 7 ++++++-
> > kernel/events/core.c | 6 +++---
> > 2 files changed, 9 insertions(+), 4 deletions(-)
> >
> > diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
> > index 2027809..fea0ddf 100644
> > --- a/include/linux/perf_event.h
> > +++ b/include/linux/perf_event.h
> > @@ -761,13 +761,18 @@ static inline bool is_sampling_event(struct
> > perf_event *event) }
> >
> > /*
> > - * Return 1 for a software event, 0 for a hardware event
> > + * Return 1 for a software event, 0 for other event
> > */
> > static inline int is_software_event(struct perf_event *event) {
> > return event->pmu->task_ctx_nr == perf_sw_context; }
> >
> > +static inline int is_hardware_event(struct perf_event *event) {
> > + return event->pmu->task_ctx_nr == perf_hw_context; }
> > +
> > extern struct static_key
> perf_swevent_enabled[PERF_COUNT_SW_MAX];
> >
> > extern void ___perf_sw_event(u32, u64, struct pt_regs *, u64); diff
> > --git a/kernel/events/core.c b/kernel/events/core.c index
> > d3dae34..9077867 100644
> > --- a/kernel/events/core.c
> > +++ b/kernel/events/core.c
> > @@ -1347,7 +1347,7 @@ static void perf_group_attach(struct
> perf_event *event)
> > WARN_ON_ONCE(group_leader->ctx != event->ctx);
> >
> > if (group_leader->group_flags & PERF_GROUP_SOFTWARE &&
> > - !is_software_event(event))
> > + is_hardware_event(event))
> > group_leader->group_flags &= ~PERF_GROUP_SOFTWARE;
> >
> > list_add_tail(&event->group_entry, &group_leader->sibling_list);
> @@
> > -1553,7 +1553,7 @@ event_sched_out(struct perf_event *event,
> > event->pmu->del(event, 0);
> > event->oncpu = -1;
> >
> > - if (!is_software_event(event))
> > + if (is_hardware_event(event))
> > cpuctx->active_oncpu--;
> > if (!--ctx->nr_active)
> > perf_event_ctx_deactivate(ctx);
> > @@ -1881,7 +1881,7 @@ event_sched_in(struct perf_event *event,
> > goto out;
> > }
> >
> > - if (!is_software_event(event))
> > + if (is_hardware_event(event))
> > cpuctx->active_oncpu++;
> > if (!ctx->nr_active++)
> > perf_event_ctx_activate(ctx);
>
> ... whereby we won't accuont uncore events as active, and thereforef will
> never perform throttling.
>
> That doesn't sound right.
I think active_oncpu should only impact if the group is exclusive.
The changes will make pure perf_invalid_context event group never exclusive.
If that's a problem, I will change this part back.
Thanks,
Kan
>
> Mark.
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