diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 7d723ad..df85c1f 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -78,7 +78,7 @@
 static int			realtime_prio			=      0;
 static bool			group				=  false;
 static unsigned int		page_size;
-static unsigned int		mmap_pages			=     16;
+static unsigned int		mmap_pages			=    128;
 static int			freq				=   1000; /* 1 KHz */
 
 static int			delay_secs			=      2;
@@ -991,8 +991,7 @@
 
 static void event__process_sample(const event_t *self,
 				  struct sample_data *sample,
-				  struct perf_session *session,
-				  struct perf_evsel *evsel)
+				  struct perf_session *session)
 {
 	u64 ip = self->ip.ip;
 	struct sym_entry *syme;
@@ -1085,8 +1084,12 @@
 
 	syme = symbol__priv(al.sym);
 	if (!syme->skip) {
-		syme->count[evsel->idx]++;
+		struct perf_evsel *evsel;
+
 		syme->origin = origin;
+		evsel = perf_evlist__id2evsel(evsel_list, sample->id);
+		assert(evsel != NULL);
+		syme->count[evsel->idx]++;
 		record_precise_ip(syme, evsel->idx, ip);
 		pthread_mutex_lock(&active_symbols_lock);
 		if (list_empty(&syme->node) || !syme->node.next)
@@ -1095,11 +1098,9 @@
 	}
 }
 
-static void perf_session__mmap_read_counter(struct perf_session *self,
-					    struct perf_evsel *evsel,
-					    int cpu, int thread_idx)
+static void perf_session__mmap_read_cpu(struct perf_session *self, int cpu)
 {
-	struct perf_mmap *md = xyarray__entry(evsel->mmap, cpu, thread_idx);
+	struct perf_mmap *md = &evsel_list->mmap[cpu];
 	unsigned int head = perf_mmap__read_head(md);
 	unsigned int old = md->prev;
 	unsigned char *data = md->base + page_size;
@@ -1153,7 +1154,7 @@
 
 		event__parse_sample(event, self, &sample);
 		if (event->header.type == PERF_RECORD_SAMPLE)
-			event__process_sample(event, &sample, self, evsel);
+			event__process_sample(event, &sample, self);
 		else
 			event__process(event, &sample, self);
 		old += size;
@@ -1164,19 +1165,10 @@
 
 static void perf_session__mmap_read(struct perf_session *self)
 {
-	struct perf_evsel *counter;
-	int i, thread_index;
+	int i;
 
-	for (i = 0; i < cpus->nr; i++) {
-		list_for_each_entry(counter, &evsel_list->entries, node) {
-			for (thread_index = 0;
-				thread_index < threads->nr;
-				thread_index++) {
-				perf_session__mmap_read_counter(self,
-					counter, i, thread_index);
-			}
-		}
-	}
+	for (i = 0; i < cpus->nr; i++)
+		perf_session__mmap_read_cpu(self, i);
 }
 
 static void start_counters(struct perf_evlist *evlist)
@@ -1194,6 +1186,11 @@
 			attr->sample_freq = freq;
 		}
 
+		if (evlist->nr_entries > 1) {
+			attr->sample_type |= PERF_SAMPLE_ID;
+			attr->read_format |= PERF_FORMAT_ID;
+		}
+
 		attr->mmap = 1;
 try_again:
 		if (perf_evsel__open(counter, cpus, threads, group, inherit) < 0) {
@@ -1225,15 +1222,16 @@
 			die("No CONFIG_PERF_EVENTS=y kernel support configured?\n");
 			exit(-1);
 		}
-
-		if (perf_evsel__mmap(counter, cpus, threads, mmap_pages, evlist) < 0)
-			die("failed to mmap with %d (%s)\n", errno, strerror(errno));
 	}
+
+	if (perf_evlist__mmap(evlist, cpus, threads, mmap_pages, true) < 0)
+		die("failed to mmap with %d (%s)\n", errno, strerror(errno));
 }
 
 static int __cmd_top(void)
 {
 	pthread_t thread;
+	struct perf_evsel *first;
 	int ret;
 	/*
 	 * FIXME: perf_session__new should allow passing a O_MMAP, so that all this
@@ -1249,6 +1247,8 @@
 		event__synthesize_threads(event__process, session);
 
 	start_counters(evsel_list);
+	first = list_entry(evsel_list->entries.next, struct perf_evsel, node);
+	perf_session__set_sample_type(session, first->attr.sample_type);
 
 	/* Wait for a minimal set of events before starting the snapshot */
 	poll(evsel_list->pollfd, evsel_list->nr_fds, 100);
@@ -1394,8 +1394,7 @@
 		usage_with_options(top_usage, options);
 
 	list_for_each_entry(pos, &evsel_list->entries, node) {
-		if (perf_evsel__alloc_mmap(pos, cpus->nr, threads->nr) < 0 ||
-		    perf_evsel__alloc_fd(pos, cpus->nr, threads->nr) < 0)
+		if (perf_evsel__alloc_fd(pos, cpus->nr, threads->nr) < 0)
 			goto out_free_fd;
 		/*
 		 * Fill in the ones not specifically initialized via -c:
@@ -1406,7 +1405,8 @@
 		pos->attr.sample_period = default_interval;
 	}
 
-	if (perf_evlist__alloc_pollfd(evsel_list, cpus->nr, threads->nr) < 0)
+	if (perf_evlist__alloc_pollfd(evsel_list, cpus->nr, threads->nr) < 0 ||
+	    perf_evlist__alloc_mmap(evsel_list, cpus->nr) < 0)
 		goto out_free_fd;
 
 	sym_evsel = list_entry(evsel_list->entries.next, struct perf_evsel, node);
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 6d41292..deb82a4 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -3,11 +3,18 @@
 #include "evsel.h"
 #include "util.h"
 
+#include <linux/bitops.h>
+#include <linux/hash.h>
+
 struct perf_evlist *perf_evlist__new(void)
 {
 	struct perf_evlist *evlist = zalloc(sizeof(*evlist));
 
 	if (evlist != NULL) {
+		int i;
+
+		for (i = 0; i < PERF_EVLIST__HLIST_SIZE; ++i)
+			INIT_HLIST_HEAD(&evlist->heads[i]);
 		INIT_LIST_HEAD(&evlist->entries);
 	}
 
@@ -29,6 +36,7 @@
 void perf_evlist__delete(struct perf_evlist *evlist)
 {
 	perf_evlist__purge(evlist);
+	free(evlist->mmap);
 	free(evlist->pollfd);
 	free(evlist);
 }
@@ -68,3 +76,22 @@
 	evlist->pollfd[evlist->nr_fds].events = POLLIN;
 	evlist->nr_fds++;
 }
+
+struct perf_evsel *perf_evlist__id2evsel(struct perf_evlist *evlist, u64 id)
+{
+	struct hlist_head *head;
+	struct hlist_node *pos;
+	struct perf_sample_id *sid;
+	int hash;
+
+	if (evlist->nr_entries == 1)
+		return list_entry(evlist->entries.next, struct perf_evsel, node);
+
+	hash = hash_64(id, PERF_EVLIST__HLIST_BITS);
+	head = &evlist->heads[hash];
+
+	hlist_for_each_entry(sid, pos, head, node)
+		if (sid->id == id)
+			return sid->evsel;
+	return NULL;
+}
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index 16bbfcb..dbfcc79 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -2,13 +2,20 @@
 #define __PERF_EVLIST_H 1
 
 #include <linux/list.h>
+#include "../perf.h"
 
 struct pollfd;
 
+#define PERF_EVLIST__HLIST_BITS 8
+#define PERF_EVLIST__HLIST_SIZE (1 << PERF_EVLIST__HLIST_BITS)
+
 struct perf_evlist {
 	struct list_head entries;
+	struct hlist_head heads[PERF_EVLIST__HLIST_SIZE];
 	int		 nr_entries;
 	int		 nr_fds;
+	int		 mmap_len;
+	struct perf_mmap *mmap;
 	struct pollfd	 *pollfd;
 };
 
@@ -23,4 +30,6 @@
 int perf_evlist__alloc_pollfd(struct perf_evlist *evlist, int ncpus, int nthreads);
 void perf_evlist__add_pollfd(struct perf_evlist *evlist, int fd);
 
+struct perf_evsel *perf_evlist__id2evsel(struct perf_evlist *evlist, u64 id);
+
 #endif /* __PERF_EVLIST_H */
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index f500695..ee49035 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -8,7 +8,11 @@
 #include <unistd.h>
 #include <sys/mman.h>
 
+#include <linux/bitops.h>
+#include <linux/hash.h>
+
 #define FD(e, x, y) (*(int *)xyarray__entry(e->fd, x, y))
+#define SID(e, x, y) xyarray__entry(e->id, x, y)
 
 struct perf_evsel *perf_evsel__new(struct perf_event_attr *attr, int idx)
 {
@@ -29,6 +33,12 @@
 	return evsel->fd != NULL ? 0 : -ENOMEM;
 }
 
+int perf_evsel__alloc_id(struct perf_evsel *evsel, int ncpus, int nthreads)
+{
+	evsel->id = xyarray__new(ncpus, nthreads, sizeof(struct perf_sample_id));
+	return evsel->id != NULL ? 0 : -ENOMEM;
+}
+
 int perf_evsel__alloc_counts(struct perf_evsel *evsel, int ncpus)
 {
 	evsel->counts = zalloc((sizeof(*evsel->counts) +
@@ -42,6 +52,12 @@
 	evsel->fd = NULL;
 }
 
+void perf_evsel__free_id(struct perf_evsel *evsel)
+{
+	xyarray__delete(evsel->id);
+	evsel->id = NULL;
+}
+
 void perf_evsel__close_fd(struct perf_evsel *evsel, int ncpus, int nthreads)
 {
 	int cpu, thread;
@@ -53,32 +69,29 @@
 		}
 }
 
-void perf_evsel__munmap(struct perf_evsel *evsel, int ncpus, int nthreads)
+void perf_evlist__munmap(struct perf_evlist *evlist, int ncpus)
 {
-	struct perf_mmap *mm;
-	int cpu, thread;
+	int cpu;
 
-	for (cpu = 0; cpu < ncpus; cpu++)
-		for (thread = 0; thread < nthreads; ++thread) {
-			mm = xyarray__entry(evsel->mmap, cpu, thread);
-			if (mm->base != NULL) {
-				munmap(mm->base, evsel->mmap_len);
-				mm->base = NULL;
-			}
+	for (cpu = 0; cpu < ncpus; cpu++) {
+		if (evlist->mmap[cpu].base != NULL) {
+			munmap(evlist->mmap[cpu].base, evlist->mmap_len);
+			evlist->mmap[cpu].base = NULL;
 		}
+	}
 }
 
-int perf_evsel__alloc_mmap(struct perf_evsel *evsel, int ncpus, int nthreads)
+int perf_evlist__alloc_mmap(struct perf_evlist *evlist, int ncpus)
 {
-	evsel->mmap = xyarray__new(ncpus, nthreads, sizeof(struct perf_mmap));
-	return evsel->mmap != NULL ? 0 : -ENOMEM;
+	evlist->mmap = zalloc(ncpus * sizeof(struct perf_mmap));
+	return evlist->mmap != NULL ? 0 : -ENOMEM;
 }
 
 void perf_evsel__delete(struct perf_evsel *evsel)
 {
 	assert(list_empty(&evsel->node));
 	xyarray__delete(evsel->fd);
-	xyarray__delete(evsel->mmap);
+	xyarray__delete(evsel->id);
 	free(evsel);
 }
 
@@ -235,47 +248,110 @@
 	return __perf_evsel__open(evsel, &empty_cpu_map.map, threads, group, inherit);
 }
 
-int perf_evsel__mmap(struct perf_evsel *evsel, struct cpu_map *cpus,
-		     struct thread_map *threads, int pages,
-		     struct perf_evlist *evlist)
+static int __perf_evlist__mmap(struct perf_evlist *evlist, int cpu, int prot,
+			       int mask, int fd)
+{
+	evlist->mmap[cpu].prev = 0;
+	evlist->mmap[cpu].mask = mask;
+	evlist->mmap[cpu].base = mmap(NULL, evlist->mmap_len, prot,
+				      MAP_SHARED, fd, 0);
+	if (evlist->mmap[cpu].base == MAP_FAILED)
+		return -1;
+
+	perf_evlist__add_pollfd(evlist, fd);
+	return 0;
+}
+
+static int perf_evlist__id_hash(struct perf_evlist *evlist, struct perf_evsel *evsel,
+			       int cpu, int thread, int fd)
+{
+	struct perf_sample_id *sid;
+	u64 read_data[4] = { 0, };
+	int hash, id_idx = 1; /* The first entry is the counter value */
+
+	if (!(evsel->attr.read_format & PERF_FORMAT_ID) ||
+	    read(fd, &read_data, sizeof(read_data)) == -1)
+		return -1;
+
+	if (evsel->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
+		++id_idx;
+	if (evsel->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
+		++id_idx;
+
+	sid = SID(evsel, cpu, thread);
+	sid->id = read_data[id_idx];
+	sid->evsel = evsel;
+	hash = hash_64(sid->id, PERF_EVLIST__HLIST_BITS);
+	hlist_add_head(&sid->node, &evlist->heads[hash]);
+	return 0;
+}
+
+/** perf_evlist__mmap - Create per cpu maps to receive events
+ *
+ * @evlist - list of events
+ * @cpus - cpu map being monitored
+ * @threads - threads map being monitored
+ * @pages - map length in pages
+ * @overwrite - overwrite older events?
+ *
+ * If overwrite is false the user needs to signal event consuption using:
+ *
+ *	struct perf_mmap *m = &evlist->mmap[cpu];
+ *	unsigned int head = perf_mmap__read_head(m);
+ *
+ *	perf_mmap__write_tail(m, head)
+ */
+int perf_evlist__mmap(struct perf_evlist *evlist, struct cpu_map *cpus,
+		      struct thread_map *threads, int pages, bool overwrite)
 {
 	unsigned int page_size = sysconf(_SC_PAGE_SIZE);
 	int mask = pages * page_size - 1, cpu;
-	struct perf_mmap *mm;
-	int thread;
+	struct perf_evsel *first_evsel, *evsel;
+	int thread, prot = PROT_READ | (overwrite ? 0 : PROT_WRITE);
 
-	if (evsel->mmap == NULL &&
-	    perf_evsel__alloc_mmap(evsel, cpus->nr, threads->nr) < 0)
+	if (evlist->mmap == NULL &&
+	    perf_evlist__alloc_mmap(evlist, cpus->nr) < 0)
 		return -ENOMEM;
 
-	evsel->mmap_len = (pages + 1) * page_size;
+	if (evlist->pollfd == NULL &&
+	    perf_evlist__alloc_pollfd(evlist, cpus->nr, threads->nr) < 0)
+		return -ENOMEM;
 
-	for (cpu = 0; cpu < cpus->nr; cpu++) {
-		for (thread = 0; thread < threads->nr; thread++) {
-			mm = xyarray__entry(evsel->mmap, cpu, thread);
-			mm->prev = 0;
-			mm->mask = mask;
-			mm->base = mmap(NULL, evsel->mmap_len, PROT_READ,
-					MAP_SHARED, FD(evsel, cpu, thread), 0);
-			if (mm->base == MAP_FAILED)
-				goto out_unmap;
+	evlist->mmap_len = (pages + 1) * page_size;
+	first_evsel = list_entry(evlist->entries.next, struct perf_evsel, node);
 
-			if (evlist != NULL)
-				 perf_evlist__add_pollfd(evlist, FD(evsel, cpu, thread));
+	list_for_each_entry(evsel, &evlist->entries, node) {
+		if ((evsel->attr.read_format & PERF_FORMAT_ID) &&
+		    evsel->id == NULL &&
+		    perf_evsel__alloc_id(evsel, cpus->nr, threads->nr) < 0)
+			return -ENOMEM;
+
+		for (cpu = 0; cpu < cpus->nr; cpu++) {
+			for (thread = 0; thread < threads->nr; thread++) {
+				int fd = FD(evsel, cpu, thread);
+
+				if (evsel->idx || thread) {
+					if (ioctl(fd, PERF_EVENT_IOC_SET_OUTPUT,
+						  FD(first_evsel, cpu, 0)) != 0)
+						goto out_unmap;
+				} else if (__perf_evlist__mmap(evlist, cpu, prot, mask, fd) < 0)
+					goto out_unmap;
+
+				if ((evsel->attr.read_format & PERF_FORMAT_ID) &&
+				    perf_evlist__id_hash(evlist, evsel, cpu, thread, fd) < 0)
+					goto out_unmap;
+			}
 		}
 	}
 
 	return 0;
 
 out_unmap:
-	do {
-		while (--thread >= 0) {
-			mm = xyarray__entry(evsel->mmap, cpu, thread);
-			munmap(mm->base, evsel->mmap_len);
-			mm->base = NULL;
+	for (cpu = 0; cpu < cpus->nr; cpu++) {
+		if (evlist->mmap[cpu].base != NULL) {
+			munmap(evlist->mmap[cpu].base, evlist->mmap_len);
+			evlist->mmap[cpu].base = NULL;
 		}
-		thread = threads->nr;
-	} while (--cpu >= 0);
-
+	}
 	return -1;
 }
diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index c8fbef2..667ee4e 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -24,14 +24,25 @@
 	struct perf_counts_values cpu[];
 };
 
+struct perf_evsel;
+
+/*
+ * Per fd, to map back from PERF_SAMPLE_ID to evsel, only used when there are
+ * more than one entry in the evlist.
+ */
+struct perf_sample_id {
+	struct hlist_node 	node;
+	u64		 	id;
+	struct perf_evsel	*evsel;
+};
+
 struct perf_evsel {
 	struct list_head	node;
 	struct perf_event_attr	attr;
 	char			*filter;
 	struct xyarray		*fd;
-	struct xyarray		*mmap;
+	struct xyarray		*id;
 	struct perf_counts	*counts;
-	size_t			mmap_len;
 	int			idx;
 	void			*priv;
 };
@@ -44,9 +55,11 @@
 void perf_evsel__delete(struct perf_evsel *evsel);
 
 int perf_evsel__alloc_fd(struct perf_evsel *evsel, int ncpus, int nthreads);
+int perf_evsel__alloc_id(struct perf_evsel *evsel, int ncpus, int nthreads);
 int perf_evsel__alloc_counts(struct perf_evsel *evsel, int ncpus);
-int perf_evsel__alloc_mmap(struct perf_evsel *evsel, int ncpus, int nthreads);
+int perf_evlist__alloc_mmap(struct perf_evlist *evlist, int ncpus);
 void perf_evsel__free_fd(struct perf_evsel *evsel);
+void perf_evsel__free_id(struct perf_evsel *evsel);
 void perf_evsel__close_fd(struct perf_evsel *evsel, int ncpus, int nthreads);
 
 int perf_evsel__open_per_cpu(struct perf_evsel *evsel,
@@ -55,10 +68,9 @@
 				struct thread_map *threads, bool group, bool inherit);
 int perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
 		     struct thread_map *threads, bool group, bool inherit);
-int perf_evsel__mmap(struct perf_evsel *evsel, struct cpu_map *cpus,
-		     struct thread_map *threads, int pages,
-		     struct perf_evlist *evlist);
-void perf_evsel__munmap(struct perf_evsel *evsel, int ncpus, int nthreads);
+int perf_evlist__mmap(struct perf_evlist *evlist, struct cpu_map *cpus,
+		      struct thread_map *threads, int pages, bool overwrite);
+void perf_evlist__munmap(struct perf_evlist *evlist, int ncpus);
 
 #define perf_evsel__match(evsel, t, c)		\
 	(evsel->attr.type == PERF_TYPE_##t &&	\