Messages in this thread | | | Subject | Re: [PATCH v2 1/6] perf: Add interface to add general events to sysfs | From | Lin Ming <> | Date | Mon, 18 Jul 2011 22:00:15 +0800 |
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On Mon, 2011-07-18 at 21:34 +0800, Peter Zijlstra wrote: > On Fri, 2011-07-15 at 14:34 +0000, Lin Ming wrote: > > PMU can implement ::add_events() to add its general events to sysfs. > > > > For example, > > > > /sys/bus/event_source/devices/uncore/events > > └── cycle > > > > Signed-off-by: Lin Ming <ming.m.lin@intel.com> > > --- > > include/linux/perf_event.h | 9 +++++++ > > kernel/events/core.c | 52 ++++++++++++++++++++++++++++++++++++++++++++ > > 2 files changed, 61 insertions(+), 0 deletions(-) > > > > diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h > > index 3f2711c..14337a3 100644 > > --- a/include/linux/perf_event.h > > +++ b/include/linux/perf_event.h > > @@ -676,6 +676,14 @@ struct pmu { > > * for each successful ->add() during the transaction. > > */ > > void (*cancel_txn) (struct pmu *pmu); /* optional */ > > + > > + void (*add_events) (void); > > +}; > > I'd rather not have a function pointer here, and all the kobj thingies > can be hooking into the existing struct device, right?
Right.
> > > +struct pmu_event { > > + char name[64]; > > + u64 config; > > + struct kobj_attribute attr; > > }; > > Can't this live in kerne/event/internal.h?
Yes, it can, with the new interface perf_pmu_add_event(struct pmu *pmu, const char *name, u64 config)
> > > /** > > @@ -941,6 +949,7 @@ struct perf_output_handle { > > > > extern int perf_pmu_register(struct pmu *pmu, char *name, int type); > > extern void perf_pmu_unregister(struct pmu *pmu); > > +extern void perf_pmu_add_events(struct pmu *pmu, struct pmu_event events[], int count); > > > > extern int perf_num_counters(void); > > extern const char *perf_pmu_name(void); > > diff --git a/kernel/events/core.c b/kernel/events/core.c > > index 0567e32..9f4f463 100644 > > --- a/kernel/events/core.c > > +++ b/kernel/events/core.c > > @@ -5571,6 +5571,8 @@ static int pmu_dev_alloc(struct pmu *pmu) > > if (ret) > > goto free_dev; > > > > + if (pmu->add_events) > > + pmu->add_events(); > > out: > > return ret; > > > > @@ -7035,4 +7037,54 @@ struct cgroup_subsys perf_subsys = { > > .exit = perf_cgroup_exit, > > .attach_task = perf_cgroup_attach_task, > > }; > > + > > +static ssize_t pmu_event_show(struct kobject *kobj, > > + struct kobj_attribute *attr, char *buf) > > +{ > > + struct pmu_event *event = container_of(attr, struct pmu_event, attr); > > + int size; > > + > > + size = sprintf(buf, "%lld\n", event->config); > > + > > + return size; > > +} > > + > > +void perf_pmu_add_events(struct pmu *pmu, struct pmu_event events[], int count) > > +{ > > + struct attribute_group *attr_group = NULL; > > + struct attribute **all_attrs = NULL; > > + struct kobj_attribute *event_attr; > > + struct pmu_event *event; > > + int i; > > + > > + attr_group = kzalloc(sizeof(*attr_group), GFP_KERNEL); > > + if (!attr_group) > > + return; > > + attr_group->name = "events"; > > + > > + all_attrs = kzalloc(sizeof(*all_attrs) * (count + 1), GFP_KERNEL); > > + if (!all_attrs) > > + goto fail; > > + > > + for (i = 0; i < count; i++) { > > + event = &events[i]; > > + event_attr = &event->attr; > > + > > + sysfs_attr_init(&event_attr->attr); > > + event_attr->attr.name = event->name; > > + event_attr->attr.mode = 0444; > > + event_attr->show = pmu_event_show; > > + > > + all_attrs[i] = &event_attr->attr; > > + } > > + > > + attr_group->attrs = all_attrs; > > + if (!sysfs_create_group(&pmu->dev->kobj, attr_group)) > > + return; > > + > > +fail: > > + kfree(attr_group); > > + kfree(all_attrs); > > +} > > + > > #endif /* CONFIG_CGROUP_PERF */ > > Uhm, why does this live under CONFIG_CGROUP_PERF?
Sorry, my mistake. I meant to put it at the end of the file.
> > Also, I would prefer an interface like: > > int perf_pmu_add_event(struct pmu *pmu, const char *name, u64 config) > { > } > > which would create the events directory if not already present and > allocate and add a pmu_sysfs_event thingy.
That's better.
Thanks.
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