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authorAndi Kleen <ak@linux.intel.com>2016-05-19 17:09:56 -0700
committerIngo Molnar <mingo@kernel.org>2016-06-03 09:41:22 +0200
commitfc07e9f983b4b11922c22b6cccadc1f342f05a4c (patch)
treef30227eecbbc2b5c87bffc9546e55013246b5788 /arch/x86/events
parent70b8301f6b8f7bc053377a9cbd0c4e42e29d9807 (diff)
perf/x86: Support sysfs files depending on SMT status
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. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: acme@kernel.org Cc: jolsa@kernel.org Link: http://lkml.kernel.org/r/1463703002-19686-3-git-send-email-andi@firstfloor.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/events')
-rw-r--r--arch/x86/events/core.c23
-rw-r--r--arch/x86/events/perf_event.h10
2 files changed, 33 insertions, 0 deletions
diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index 33787ee817f0..929655db5084 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -1622,6 +1622,29 @@ ssize_t events_sysfs_show(struct device *dev, struct device_attribute *attr, cha
}
EXPORT_SYMBOL_GPL(events_sysfs_show);
+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);
+
+ /*
+ * Report conditional events depending on Hyper-Threading.
+ *
+ * This is overly conservative as usually the HT special
+ * handling is not needed if the other CPU thread is idle.
+ *
+ * Note this does not (and 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.
+ */
+ return sprintf(page, "%s",
+ topology_max_smt_threads() > 1 ?
+ 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/events/perf_event.h b/arch/x86/events/perf_event.h
index 8bd764df815d..e2d7285a2dac 100644
--- a/arch/x86/events/perf_event.h
+++ b/arch/x86/events/perf_event.h
@@ -668,6 +668,14 @@ 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)
@@ -803,6 +811,8 @@ struct attribute **merge_attr(struct attribute **a, struct attribute **b);
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);
#ifdef CONFIG_CPU_SUP_AMD