Commit fc07e9f9 authored by Andi Kleen's avatar Andi Kleen Committed by Ingo Molnar
Browse files

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: default avatarAndi Kleen <ak@linux.intel.com>
Signed-off-by: default avatarPeter 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: default avatarIngo Molnar <mingo@kernel.org>
parent 70b8301f

arch/x86/events/core.c

+23 −0
Original line number Diff line number Diff line
@@ -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	);

arch/x86/events/perf_event.h

+10 −0
Original line number Diff line number Diff line
@@ -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

include/linux/perf_event.h

+7 −0
Original line number Diff line number Diff line
@@ -1334,6 +1334,13 @@ 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);

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