Andi, On Tue, Dec 15, 2015 at 4:54 PM, Andi Kleen <[email protected]> wrote: > > From: Andi Kleen <[email protected]> > > Add a way to show different sysfs events attributes depending on > HyperThreading is on or off. This is difficult to determine > early at boot, so we just do it dynamically when the sysfs > attribute is read. > The only attribute I can think of is the any thread bit. But I do not see this in this patch. Is this somewhere else?
> > Signed-off-by: Andi Kleen <[email protected]> > --- > arch/x86/kernel/cpu/perf_event.c | 34 ++++++++++++++++++++++++++++++++++ > arch/x86/kernel/cpu/perf_event.h | 10 ++++++++++ > include/linux/perf_event.h | 7 +++++++ > 3 files changed, 51 insertions(+) > > diff --git a/arch/x86/kernel/cpu/perf_event.c > b/arch/x86/kernel/cpu/perf_event.c > index 9dfbba5..976686f 100644 > --- a/arch/x86/kernel/cpu/perf_event.c > +++ b/arch/x86/kernel/cpu/perf_event.c > @@ -1590,6 +1590,40 @@ ssize_t events_sysfs_show(struct device *dev, struct > device_attribute *attr, > return x86_pmu.events_sysfs_show(page, config); > } > > +ssize_t events_ht_sysfs_show(struct device *dev, struct device_attribute > *attr, > + char *page) > +{ > + struct perf_pmu_events_ht_attr *pmu_attr = > + container_of(attr, struct perf_pmu_events_ht_attr, attr); > + bool ht_on = false; > + int cpu; > + > + /* > + * Report conditional events depending on Hyper-Threading. > + * > + * Check all online CPUs if any have a thread sibling, > + * as perf may measure any of them. > + * > + * This is overly conservative as usually the HT special > + * handling is not needed if the other CPU thread is idle. > + * > + * Note this does not (cannot) handle the case when thread > + * siblings are invisible, for example with virtualization > + * if they are owned by some other guest. The user tool > + * has to re-read when a thread sibling gets onlined later. > + */ > + for_each_online_cpu (cpu) { > + ht_on = cpumask_weight(topology_sibling_cpumask(cpu)) > 1; > + if (ht_on) > + break; > + } > + > + return sprintf(page, "%s", > + ht_on ? > + pmu_attr->event_str_ht : > + pmu_attr->event_str_noht); > +} > + > EVENT_ATTR(cpu-cycles, CPU_CYCLES ); > EVENT_ATTR(instructions, INSTRUCTIONS ); > EVENT_ATTR(cache-references, CACHE_REFERENCES ); > diff --git a/arch/x86/kernel/cpu/perf_event.h > b/arch/x86/kernel/cpu/perf_event.h > index 799e6bd..ce87cd6 100644 > --- a/arch/x86/kernel/cpu/perf_event.h > +++ b/arch/x86/kernel/cpu/perf_event.h > @@ -660,6 +660,14 @@ static struct perf_pmu_events_attr event_attr_##v = { > \ > .event_str = str, \ > }; > > +#define EVENT_ATTR_STR_HT(_name, v, noht, ht) \ > +static struct perf_pmu_events_ht_attr event_attr_##v = { \ > + .attr = __ATTR(_name, 0444, events_ht_sysfs_show, NULL),\ > + .id = 0, \ > + .event_str_noht = noht, \ > + .event_str_ht = ht, \ > +} > + > extern struct x86_pmu x86_pmu __read_mostly; > > static inline bool x86_pmu_has_lbr_callstack(void) > @@ -919,6 +927,8 @@ int knc_pmu_init(void); > > ssize_t events_sysfs_show(struct device *dev, struct device_attribute *attr, > char *page); > +ssize_t events_ht_sysfs_show(struct device *dev, struct device_attribute > *attr, > + char *page); > > static inline int is_ht_workaround_enabled(void) > { > diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h > index f9828a4..ea2d830 100644 > --- a/include/linux/perf_event.h > +++ b/include/linux/perf_event.h > @@ -1166,6 +1166,13 @@ struct perf_pmu_events_attr { > const char *event_str; > }; > > +struct perf_pmu_events_ht_attr { > + struct device_attribute attr; > + u64 id; > + const char *event_str_ht; > + const char *event_str_noht; > +}; > + > ssize_t perf_event_sysfs_show(struct device *dev, struct device_attribute > *attr, > char *page); > > -- > 2.4.3 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
