Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf changes from Ingo Molnar:
 "There are lots of improvements, the biggest changes are:

  Main kernel side changes:

   - Improve uprobes performance by adding 'pre-filtering' support, by
     Oleg Nesterov.

   - Make some POWER7 events available in sysfs, equivalent to what was
     done on x86, from Sukadev Bhattiprolu.

   - tracing updates by Steve Rostedt - mostly misc fixes and smaller
     improvements.

   - Use perf/event tracing to report PCI Express advanced errors, by
     Tony Luck.

   - Enable northbridge performance counters on AMD family 15h, by Jacob
     Shin.

   - This tracing commit:

        tracing: Remove the extra 4 bytes of padding in events

     changes the ABI.  All involved parties (PowerTop in particular)
     seem to agree that it's safe to do now with the introduction of
     libtraceevent, but the devil is in the details ...

  Main tooling side changes:

   - Add 'event group view', from Namyung Kim:

     To use it, 'perf record' should group events when recording.  And
     then perf report parses the saved group relation from file header
     and prints them together if --group option is provided.  You can
     use the 'perf evlist' command to see event group information:

        $ perf record -e '{ref-cycles,cycles}' noploop 1
        [ perf record: Woken up 2 times to write data ]
        [ perf record: Captured and wrote 0.385 MB perf.data (~16807 samples) ]

        $ perf evlist --group
        {ref-cycles,cycles}

     With this example, default perf report will show you each event
     separately.

     You can use --group option to enable event group view:

        $ perf report --group
        ...
        # group: {ref-cycles,cycles}
        # ========
        # Samples: 7K of event 'anon group { ref-cycles, cycles }'
        # Event count (approx.): 6876107743
        #
        #         Overhead  Command      Shared Object                      Symbol
        # ................  .......  .................  ..........................
            99.84%  99.76%  noploop  noploop            [.] main
             0.07%   0.00%  noploop  ld-2.15.so         [.] strcmp
             0.03%   0.00%  noploop  [kernel.kallsyms]  [k] timerqueue_del
             0.03%   0.03%  noploop  [kernel.kallsyms]  [k] sched_clock_cpu
             0.02%   0.00%  noploop  [kernel.kallsyms]  [k] account_user_time
             0.01%   0.00%  noploop  [kernel.kallsyms]  [k] __alloc_pages_nodemask
             0.00%   0.00%  noploop  [kernel.kallsyms]  [k] native_write_msr_safe
             0.00%   0.11%  noploop  [kernel.kallsyms]  [k] _raw_spin_lock
             0.00%   0.06%  noploop  [kernel.kallsyms]  [k] find_get_page
             0.00%   0.02%  noploop  [kernel.kallsyms]  [k] rcu_check_callbacks
             0.00%   0.02%  noploop  [kernel.kallsyms]  [k] __current_kernel_time

     As you can see the Overhead column now contains both of ref-cycles
     and cycles and header line shows group information also - 'anon
     group { ref-cycles, cycles }'.  The output is sorted by period of
     group leader first.

   - Initial GTK+ annotate browser, from Namhyung Kim.

   - Add option for runtime switching perf data file in perf report,
     just press 's' and a menu with the valid files found in the current
     directory will be presented, from Feng Tang.

   - Add support to display whole group data for raw columns, from Jiri
     Olsa.

   - Add per processor socket count aggregation in perf stat, from
     Stephane Eranian.

   - Add interval printing in 'perf stat', from Stephane Eranian.

   - 'perf test' improvements

   - Add support for wildcards in tracepoint system name, from Jiri
     Olsa.

   - Add anonymous huge page recognition, from Joshua Zhu.

   - perf build-id cache now can show DSOs present in a perf.data file
     that are not in the cache, to integrate with build-id servers being
     put in place by organizations such as Fedora.

   - perf top now shares more of the evsel config/creation routines with
     'record', paving the way for further integration like 'top'
     snapshots, etc.

   - perf top now supports DWARF callchains.

   - Fix mmap limitations on 32-bit, fix from David Miller.

   - 'perf bench numa mem' NUMA performance measurement suite

   - ... and lots of fixes, performance improvements, cleanups and other
     improvements I failed to list - see the shortlog and git log for
     details."

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (270 commits)
  perf/x86/amd: Enable northbridge performance counters on AMD family 15h
  perf/hwbp: Fix cleanup in case of kzalloc failure
  perf tools: Fix build with bison 2.3 and older.
  perf tools: Limit unwind support to x86 archs
  perf annotate: Make it to be able to skip unannotatable symbols
  perf gtk/annotate: Fail early if it can't annotate
  perf gtk/annotate: Show source lines with gray color
  perf gtk/annotate: Support multiple event annotation
  perf ui/gtk: Implement basic GTK2 annotation browser
  perf annotate: Fix warning message on a missing vmlinux
  perf buildid-cache: Add --update option
  uprobes/perf: Avoid uprobe_apply() whenever possible
  uprobes/perf: Teach trace_uprobe/perf code to use UPROBE_HANDLER_REMOVE
  uprobes/perf: Teach trace_uprobe/perf code to pre-filter
  uprobes/perf: Teach trace_uprobe/perf code to track the active perf_event's
  uprobes: Introduce uprobe_apply()
  perf: Introduce hw_perf_event->tp_target and ->tp_list
  uprobes/perf: Always increment trace_uprobe->nhit
  uprobes/tracing: Kill uprobe_trace_consumer, embed uprobe_consumer into trace_uprobe
  uprobes/tracing: Introduce is_trace_uprobe_enabled()
  ...

1 files changed, 348 insertions, 22 deletions

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 1b16dd1..9c82f98f 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -22,6 +22,11 @@
 #include <linux/perf_event.h>
 #include "perf_regs.h"
 
+static struct {
+	bool sample_id_all;
+	bool exclude_guest;
+} perf_missing_features;
+
 #define FD(e, x, y) (*(int *)xyarray__entry(e->fd, x, y))
 
 static int __perf_evsel__sample_size(u64 sample_type)
@@ -50,11 +55,36 @@ void hists__init(struct hists *hists)
 	pthread_mutex_init(&hists->lock, NULL);
 }
 
+void __perf_evsel__set_sample_bit(struct perf_evsel *evsel,
+				  enum perf_event_sample_format bit)
+{
+	if (!(evsel->attr.sample_type & bit)) {
+		evsel->attr.sample_type |= bit;
+		evsel->sample_size += sizeof(u64);
+	}
+}
+
+void __perf_evsel__reset_sample_bit(struct perf_evsel *evsel,
+				    enum perf_event_sample_format bit)
+{
+	if (evsel->attr.sample_type & bit) {
+		evsel->attr.sample_type &= ~bit;
+		evsel->sample_size -= sizeof(u64);
+	}
+}
+
+void perf_evsel__set_sample_id(struct perf_evsel *evsel)
+{
+	perf_evsel__set_sample_bit(evsel, ID);
+	evsel->attr.read_format |= PERF_FORMAT_ID;
+}
+
 void perf_evsel__init(struct perf_evsel *evsel,
 		      struct perf_event_attr *attr, int idx)
 {
 	evsel->idx	   = idx;
 	evsel->attr	   = *attr;
+	evsel->leader	   = evsel;
 	INIT_LIST_HEAD(&evsel->node);
 	hists__init(&evsel->hists);
 	evsel->sample_size = __perf_evsel__sample_size(attr->sample_type);
@@ -404,6 +434,31 @@ const char *perf_evsel__name(struct perf_evsel *evsel)
 	return evsel->name ?: "unknown";
 }
 
+const char *perf_evsel__group_name(struct perf_evsel *evsel)
+{
+	return evsel->group_name ?: "anon group";
+}
+
+int perf_evsel__group_desc(struct perf_evsel *evsel, char *buf, size_t size)
+{
+	int ret;
+	struct perf_evsel *pos;
+	const char *group_name = perf_evsel__group_name(evsel);
+
+	ret = scnprintf(buf, size, "%s", group_name);
+
+	ret += scnprintf(buf + ret, size - ret, " { %s",
+			 perf_evsel__name(evsel));
+
+	for_each_group_member(pos, evsel)
+		ret += scnprintf(buf + ret, size - ret, ", %s",
+				 perf_evsel__name(pos));
+
+	ret += scnprintf(buf + ret, size - ret, " }");
+
+	return ret;
+}
+
 /*
  * The enable_on_exec/disabled value strategy:
  *
@@ -438,13 +493,11 @@ void perf_evsel__config(struct perf_evsel *evsel,
 	struct perf_event_attr *attr = &evsel->attr;
 	int track = !evsel->idx; /* only the first counter needs these */
 
-	attr->sample_id_all = opts->sample_id_all_missing ? 0 : 1;
+	attr->sample_id_all = perf_missing_features.sample_id_all ? 0 : 1;
 	attr->inherit	    = !opts->no_inherit;
-	attr->read_format   = PERF_FORMAT_TOTAL_TIME_ENABLED |
-			      PERF_FORMAT_TOTAL_TIME_RUNNING |
-			      PERF_FORMAT_ID;
 
-	attr->sample_type  |= PERF_SAMPLE_IP | PERF_SAMPLE_TID;
+	perf_evsel__set_sample_bit(evsel, IP);
+	perf_evsel__set_sample_bit(evsel, TID);
 
 	/*
 	 * We default some events to a 1 default interval. But keep
@@ -453,7 +506,7 @@ void perf_evsel__config(struct perf_evsel *evsel,
 	if (!attr->sample_period || (opts->user_freq != UINT_MAX &&
 				     opts->user_interval != ULLONG_MAX)) {
 		if (opts->freq) {
-			attr->sample_type	|= PERF_SAMPLE_PERIOD;
+			perf_evsel__set_sample_bit(evsel, PERIOD);
 			attr->freq		= 1;
 			attr->sample_freq	= opts->freq;
 		} else {
@@ -468,16 +521,16 @@ void perf_evsel__config(struct perf_evsel *evsel,
 		attr->inherit_stat = 1;
 
 	if (opts->sample_address) {
-		attr->sample_type	|= PERF_SAMPLE_ADDR;
+		perf_evsel__set_sample_bit(evsel, ADDR);
 		attr->mmap_data = track;
 	}
 
 	if (opts->call_graph) {
-		attr->sample_type	|= PERF_SAMPLE_CALLCHAIN;
+		perf_evsel__set_sample_bit(evsel, CALLCHAIN);
 
 		if (opts->call_graph == CALLCHAIN_DWARF) {
-			attr->sample_type |= PERF_SAMPLE_REGS_USER |
-					     PERF_SAMPLE_STACK_USER;
+			perf_evsel__set_sample_bit(evsel, REGS_USER);
+			perf_evsel__set_sample_bit(evsel, STACK_USER);
 			attr->sample_regs_user = PERF_REGS_MASK;
 			attr->sample_stack_user = opts->stack_dump_size;
 			attr->exclude_callchain_user = 1;
@@ -485,20 +538,20 @@ void perf_evsel__config(struct perf_evsel *evsel,
 	}
 
 	if (perf_target__has_cpu(&opts->target))
-		attr->sample_type	|= PERF_SAMPLE_CPU;
+		perf_evsel__set_sample_bit(evsel, CPU);
 
 	if (opts->period)
-		attr->sample_type	|= PERF_SAMPLE_PERIOD;
+		perf_evsel__set_sample_bit(evsel, PERIOD);
 
-	if (!opts->sample_id_all_missing &&
+	if (!perf_missing_features.sample_id_all &&
 	    (opts->sample_time || !opts->no_inherit ||
 	     perf_target__has_cpu(&opts->target)))
-		attr->sample_type	|= PERF_SAMPLE_TIME;
+		perf_evsel__set_sample_bit(evsel, TIME);
 
 	if (opts->raw_samples) {
-		attr->sample_type	|= PERF_SAMPLE_TIME;
-		attr->sample_type	|= PERF_SAMPLE_RAW;
-		attr->sample_type	|= PERF_SAMPLE_CPU;
+		perf_evsel__set_sample_bit(evsel, TIME);
+		perf_evsel__set_sample_bit(evsel, RAW);
+		perf_evsel__set_sample_bit(evsel, CPU);
 	}
 
 	if (opts->no_delay) {
@@ -506,7 +559,7 @@ void perf_evsel__config(struct perf_evsel *evsel,
 		attr->wakeup_events = 1;
 	}
 	if (opts->branch_stack) {
-		attr->sample_type	|= PERF_SAMPLE_BRANCH_STACK;
+		perf_evsel__set_sample_bit(evsel, BRANCH_STACK);
 		attr->branch_sample_type = opts->branch_stack;
 	}
 
@@ -519,14 +572,14 @@ void perf_evsel__config(struct perf_evsel *evsel,
 	 * Disabling only independent events or group leaders,
 	 * keeping group members enabled.
 	 */
-	if (!perf_evsel__is_group_member(evsel))
+	if (perf_evsel__is_group_leader(evsel))
 		attr->disabled = 1;
 
 	/*
 	 * Setting enable_on_exec for independent events and
 	 * group leaders for traced executed by perf.
 	 */
-	if (perf_target__none(&opts->target) && !perf_evsel__is_group_member(evsel))
+	if (perf_target__none(&opts->target) && perf_evsel__is_group_leader(evsel))
 		attr->enable_on_exec = 1;
 }
 
@@ -612,6 +665,11 @@ void perf_evsel__close_fd(struct perf_evsel *evsel, int ncpus, int nthreads)
 		}
 }
 
+void perf_evsel__free_counts(struct perf_evsel *evsel)
+{
+	free(evsel->counts);
+}
+
 void perf_evsel__exit(struct perf_evsel *evsel)
 {
 	assert(list_empty(&evsel->node));
@@ -631,6 +689,28 @@ void perf_evsel__delete(struct perf_evsel *evsel)
 	free(evsel);
 }
 
+static inline void compute_deltas(struct perf_evsel *evsel,
+				  int cpu,
+				  struct perf_counts_values *count)
+{
+	struct perf_counts_values tmp;
+
+	if (!evsel->prev_raw_counts)
+		return;
+
+	if (cpu == -1) {
+		tmp = evsel->prev_raw_counts->aggr;
+		evsel->prev_raw_counts->aggr = *count;
+	} else {
+		tmp = evsel->prev_raw_counts->cpu[cpu];
+		evsel->prev_raw_counts->cpu[cpu] = *count;
+	}
+
+	count->val = count->val - tmp.val;
+	count->ena = count->ena - tmp.ena;
+	count->run = count->run - tmp.run;
+}
+
 int __perf_evsel__read_on_cpu(struct perf_evsel *evsel,
 			      int cpu, int thread, bool scale)
 {
@@ -646,6 +726,8 @@ int __perf_evsel__read_on_cpu(struct perf_evsel *evsel,
 	if (readn(FD(evsel, cpu, thread), &count, nv * sizeof(u64)) < 0)
 		return -errno;
 
+	compute_deltas(evsel, cpu, &count);
+
 	if (scale) {
 		if (count.run == 0)
 			count.val = 0;
@@ -684,6 +766,8 @@ int __perf_evsel__read(struct perf_evsel *evsel,
 		}
 	}
 
+	compute_deltas(evsel, -1, aggr);
+
 	evsel->counts->scaled = 0;
 	if (scale) {
 		if (aggr->run == 0) {
@@ -707,7 +791,7 @@ static int get_group_fd(struct perf_evsel *evsel, int cpu, int thread)
 	struct perf_evsel *leader = evsel->leader;
 	int fd;
 
-	if (!perf_evsel__is_group_member(evsel))
+	if (perf_evsel__is_group_leader(evsel))
 		return -1;
 
 	/*
@@ -738,6 +822,13 @@ static int __perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
 		pid = evsel->cgrp->fd;
 	}
 
+fallback_missing_features:
+	if (perf_missing_features.exclude_guest)
+		evsel->attr.exclude_guest = evsel->attr.exclude_host = 0;
+retry_sample_id:
+	if (perf_missing_features.sample_id_all)
+		evsel->attr.sample_id_all = 0;
+
 	for (cpu = 0; cpu < cpus->nr; cpu++) {
 
 		for (thread = 0; thread < threads->nr; thread++) {
@@ -754,13 +845,26 @@ static int __perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
 								     group_fd, flags);
 			if (FD(evsel, cpu, thread) < 0) {
 				err = -errno;
-				goto out_close;
+				goto try_fallback;
 			}
 		}
 	}
 
 	return 0;
 
+try_fallback:
+	if (err != -EINVAL || cpu > 0 || thread > 0)
+		goto out_close;
+
+	if (!perf_missing_features.exclude_guest &&
+	    (evsel->attr.exclude_guest || evsel->attr.exclude_host)) {
+		perf_missing_features.exclude_guest = true;
+		goto fallback_missing_features;
+	} else if (!perf_missing_features.sample_id_all) {
+		perf_missing_features.sample_id_all = true;
+		goto retry_sample_id;
+	}
+
 out_close:
 	do {
 		while (--thread >= 0) {
@@ -1205,3 +1309,225 @@ u64 perf_evsel__intval(struct perf_evsel *evsel, struct perf_sample *sample,
 
 	return 0;
 }
+
+static int comma_fprintf(FILE *fp, bool *first, const char *fmt, ...)
+{
+	va_list args;
+	int ret = 0;
+
+	if (!*first) {
+		ret += fprintf(fp, ",");
+	} else {
+		ret += fprintf(fp, ":");
+		*first = false;
+	}
+
+	va_start(args, fmt);
+	ret += vfprintf(fp, fmt, args);
+	va_end(args);
+	return ret;
+}
+
+static int __if_fprintf(FILE *fp, bool *first, const char *field, u64 value)
+{
+	if (value == 0)
+		return 0;
+
+	return comma_fprintf(fp, first, " %s: %" PRIu64, field, value);
+}
+
+#define if_print(field) printed += __if_fprintf(fp, &first, #field, evsel->attr.field)
+
+struct bit_names {
+	int bit;
+	const char *name;
+};
+
+static int bits__fprintf(FILE *fp, const char *field, u64 value,
+			 struct bit_names *bits, bool *first)
+{
+	int i = 0, printed = comma_fprintf(fp, first, " %s: ", field);
+	bool first_bit = true;
+
+	do {
+		if (value & bits[i].bit) {
+			printed += fprintf(fp, "%s%s", first_bit ? "" : "|", bits[i].name);
+			first_bit = false;
+		}
+	} while (bits[++i].name != NULL);
+
+	return printed;
+}
+
+static int sample_type__fprintf(FILE *fp, bool *first, u64 value)
+{
+#define bit_name(n) { PERF_SAMPLE_##n, #n }
+	struct bit_names bits[] = {
+		bit_name(IP), bit_name(TID), bit_name(TIME), bit_name(ADDR),
+		bit_name(READ), bit_name(CALLCHAIN), bit_name(ID), bit_name(CPU),
+		bit_name(PERIOD), bit_name(STREAM_ID), bit_name(RAW),
+		bit_name(BRANCH_STACK), bit_name(REGS_USER), bit_name(STACK_USER),
+		{ .name = NULL, }
+	};
+#undef bit_name
+	return bits__fprintf(fp, "sample_type", value, bits, first);
+}
+
+static int read_format__fprintf(FILE *fp, bool *first, u64 value)
+{
+#define bit_name(n) { PERF_FORMAT_##n, #n }
+	struct bit_names bits[] = {
+		bit_name(TOTAL_TIME_ENABLED), bit_name(TOTAL_TIME_RUNNING),
+		bit_name(ID), bit_name(GROUP),
+		{ .name = NULL, }
+	};
+#undef bit_name
+	return bits__fprintf(fp, "read_format", value, bits, first);
+}
+
+int perf_evsel__fprintf(struct perf_evsel *evsel,
+			struct perf_attr_details *details, FILE *fp)
+{
+	bool first = true;
+	int printed = 0;
+
+	if (details->event_group) {
+		struct perf_evsel *pos;
+
+		if (!perf_evsel__is_group_leader(evsel))
+			return 0;
+
+		if (evsel->nr_members > 1)
+			printed += fprintf(fp, "%s{", evsel->group_name ?: "");
+
+		printed += fprintf(fp, "%s", perf_evsel__name(evsel));
+		for_each_group_member(pos, evsel)
+			printed += fprintf(fp, ",%s", perf_evsel__name(pos));
+
+		if (evsel->nr_members > 1)
+			printed += fprintf(fp, "}");
+		goto out;
+	}
+
+	printed += fprintf(fp, "%s", perf_evsel__name(evsel));
+
+	if (details->verbose || details->freq) {
+		printed += comma_fprintf(fp, &first, " sample_freq=%" PRIu64,
+					 (u64)evsel->attr.sample_freq);
+	}
+
+	if (details->verbose) {
+		if_print(type);
+		if_print(config);
+		if_print(config1);
+		if_print(config2);
+		if_print(size);
+		printed += sample_type__fprintf(fp, &first, evsel->attr.sample_type);
+		if (evsel->attr.read_format)
+			printed += read_format__fprintf(fp, &first, evsel->attr.read_format);
+		if_print(disabled);
+		if_print(inherit);
+		if_print(pinned);
+		if_print(exclusive);
+		if_print(exclude_user);
+		if_print(exclude_kernel);
+		if_print(exclude_hv);
+		if_print(exclude_idle);
+		if_print(mmap);
+		if_print(comm);
+		if_print(freq);
+		if_print(inherit_stat);
+		if_print(enable_on_exec);
+		if_print(task);
+		if_print(watermark);
+		if_print(precise_ip);
+		if_print(mmap_data);
+		if_print(sample_id_all);
+		if_print(exclude_host);
+		if_print(exclude_guest);
+		if_print(__reserved_1);
+		if_print(wakeup_events);
+		if_print(bp_type);
+		if_print(branch_sample_type);
+	}
+out:
+	fputc('\n', fp);
+	return ++printed;
+}
+
+bool perf_evsel__fallback(struct perf_evsel *evsel, int err,
+			  char *msg, size_t msgsize)
+{
+	if ((err == ENOENT || err == ENXIO) &&
+	    evsel->attr.type   == PERF_TYPE_HARDWARE &&
+	    evsel->attr.config == PERF_COUNT_HW_CPU_CYCLES) {
+		/*
+		 * If it's cycles then fall back to hrtimer based
+		 * cpu-clock-tick sw counter, which is always available even if
+		 * no PMU support.
+		 *
+		 * PPC returns ENXIO until 2.6.37 (behavior changed with commit
+		 * b0a873e).
+		 */
+		scnprintf(msg, msgsize, "%s",
+"The cycles event is not supported, trying to fall back to cpu-clock-ticks");
+
+		evsel->attr.type   = PERF_TYPE_SOFTWARE;
+		evsel->attr.config = PERF_COUNT_SW_CPU_CLOCK;
+
+		free(evsel->name);
+		evsel->name = NULL;
+		return true;
+	}
+
+	return false;
+}
+
+int perf_evsel__open_strerror(struct perf_evsel *evsel,
+			      struct perf_target *target,
+			      int err, char *msg, size_t size)
+{
+	switch (err) {
+	case EPERM:
+	case EACCES:
+		return scnprintf(msg, size, "%s",
+		 "You may not have permission to collect %sstats.\n"
+		 "Consider tweaking /proc/sys/kernel/perf_event_paranoid:\n"
+		 " -1 - Not paranoid at all\n"
+		 "  0 - Disallow raw tracepoint access for unpriv\n"
+		 "  1 - Disallow cpu events for unpriv\n"
+		 "  2 - Disallow kernel profiling for unpriv",
+				 target->system_wide ? "system-wide " : "");
+	case ENOENT:
+		return scnprintf(msg, size, "The %s event is not supported.",
+				 perf_evsel__name(evsel));
+	case EMFILE:
+		return scnprintf(msg, size, "%s",
+			 "Too many events are opened.\n"
+			 "Try again after reducing the number of events.");
+	case ENODEV:
+		if (target->cpu_list)
+			return scnprintf(msg, size, "%s",
+	 "No such device - did you specify an out-of-range profile CPU?\n");
+		break;
+	case EOPNOTSUPP:
+		if (evsel->attr.precise_ip)
+			return scnprintf(msg, size, "%s",
+	"\'precise\' request may not be supported. Try removing 'p' modifier.");
+#if defined(__i386__) || defined(__x86_64__)
+		if (evsel->attr.type == PERF_TYPE_HARDWARE)
+			return scnprintf(msg, size, "%s",
+	"No hardware sampling interrupt available.\n"
+	"No APIC? If so then you can boot the kernel with the \"lapic\" boot parameter to force-enable it.");
+#endif
+		break;
+	default:
+		break;
+	}
+
+	return scnprintf(msg, size,
+	"The sys_perf_event_open() syscall returned with %d (%s) for event (%s).  \n"
+	"/bin/dmesg may provide additional information.\n"
+	"No CONFIG_PERF_EVENTS=y kernel support configured?\n",
+			 err, strerror(err), perf_evsel__name(evsel));
+}