diff --git a/Documentation/perf_counter/Makefile b/Documentation/perf_counter/Makefile
index 45daa72..49c601e 100644
--- a/Documentation/perf_counter/Makefile
+++ b/Documentation/perf_counter/Makefile
@@ -228,7 +228,6 @@
 COMPAT_OBJS =
 LIB_H =
 LIB_OBJS =
-PROGRAMS = perf-report
 SCRIPT_PERL =
 SCRIPT_SH =
 TEST_PROGRAMS =
@@ -315,6 +314,7 @@
 
 BUILTIN_OBJS += builtin-help.o
 BUILTIN_OBJS += builtin-record.o
+BUILTIN_OBJS += builtin-report.o
 BUILTIN_OBJS += builtin-stat.o
 BUILTIN_OBJS += builtin-top.o
 
@@ -811,10 +811,6 @@
 	$(RM) $(htmldocs).tar.gz $(manpages).tar.gz
 	$(RM) PERF-VERSION-FILE PERF-CFLAGS PERF-BUILD-OPTIONS
 
-# temporary hack:
-perf-report: perf-report.cc ../../include/linux/perf_counter.h Makefile
-	g++ -g -O2 -Wall -lrt -o $@ $<
-
 .PHONY: all install clean strip
 .PHONY: shell_compatibility_test please_set_SHELL_PATH_to_a_more_modern_shell
 .PHONY: .FORCE-PERF-VERSION-FILE TAGS tags cscope .FORCE-PERF-CFLAGS
diff --git a/Documentation/perf_counter/builtin-report.c b/Documentation/perf_counter/builtin-report.c
new file mode 100644
index 0000000..864f68f
--- /dev/null
+++ b/Documentation/perf_counter/builtin-report.c
@@ -0,0 +1,751 @@
+#define _GNU_SOURCE
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/time.h>
+#include <unistd.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include <limits.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <errno.h>
+#include <ctype.h>
+#include <time.h>
+#include <getopt.h>
+#include <assert.h>
+#include <search.h>
+
+#include <sys/ioctl.h>
+#include <sys/poll.h>
+#include <sys/prctl.h>
+#include <sys/wait.h>
+#include <sys/mman.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include <linux/unistd.h>
+#include <linux/types.h>
+
+#include "../../include/linux/perf_counter.h"
+#include "list.h"
+
+#define SHOW_KERNEL	1
+#define SHOW_USER	2
+#define SHOW_HV		4
+
+static char 		const *input_name = "output.perf";
+static int		input;
+static int		show_mask = SHOW_KERNEL | SHOW_USER | SHOW_HV;
+
+static unsigned long	page_size;
+static unsigned long	mmap_window = 32;
+
+static const char *perf_event_names[] = {
+	[PERF_EVENT_MMAP]   = " PERF_EVENT_MMAP",
+	[PERF_EVENT_MUNMAP] = " PERF_EVENT_MUNMAP",
+	[PERF_EVENT_COMM]   = " PERF_EVENT_COMM",
+};
+
+struct ip_event {
+	struct perf_event_header header;
+	__u64 ip;
+	__u32 pid, tid;
+};
+struct mmap_event {
+	struct perf_event_header header;
+	__u32 pid, tid;
+	__u64 start;
+	__u64 len;
+	__u64 pgoff;
+	char filename[PATH_MAX];
+};
+struct comm_event {
+	struct perf_event_header header;
+	__u32 pid,tid;
+	char comm[16];
+};
+
+typedef union event_union {
+	struct perf_event_header header;
+	struct ip_event ip;
+	struct mmap_event mmap;
+	struct comm_event comm;
+} event_t;
+
+struct section {
+	struct list_head node;
+	uint64_t	 start;
+	uint64_t	 end;
+	uint64_t	 offset;
+	char		 name[0];
+};
+
+static struct section *section__new(uint64_t start, uint64_t size,
+				    uint64_t offset, char *name)
+{
+	struct section *self = malloc(sizeof(*self) + strlen(name) + 1);
+
+	if (self != NULL) {
+		self->start  = start;
+		self->end    = start + size;
+		self->offset = offset;
+		strcpy(self->name, name);
+	}
+
+	return self;
+}
+
+static void section__delete(struct section *self)
+{
+	free(self);
+}
+
+struct symbol {
+	struct list_head node;
+	uint64_t	 start;
+	uint64_t	 end;
+	char		 name[0];
+};
+
+static struct symbol *symbol__new(uint64_t start, uint64_t len, const char *name)
+{
+	struct symbol *self = malloc(sizeof(*self) + strlen(name) + 1);
+
+	if (self != NULL) {
+		self->start = start;
+		self->end   = start + len;
+		strcpy(self->name, name);
+	}
+
+	return self;
+}
+
+static void symbol__delete(struct symbol *self)
+{
+	free(self);
+}
+
+static size_t symbol__fprintf(struct symbol *self, FILE *fp)
+{
+	return fprintf(fp, " %lx-%lx %s\n",
+		       self->start, self->end, self->name);
+}
+
+struct dso {
+	struct list_head node;
+	struct list_head sections;
+	struct list_head syms;
+	char		 name[0];
+};
+
+static struct dso *dso__new(const char *name)
+{
+	struct dso *self = malloc(sizeof(*self) + strlen(name) + 1);
+
+	if (self != NULL) {
+		strcpy(self->name, name);
+		INIT_LIST_HEAD(&self->sections);
+		INIT_LIST_HEAD(&self->syms);
+	}
+
+	return self;
+}
+
+static void dso__delete_sections(struct dso *self)
+{
+	struct section *pos, *n;
+
+	list_for_each_entry_safe(pos, n, &self->sections, node)
+		section__delete(pos);
+}
+
+static void dso__delete_symbols(struct dso *self)
+{
+	struct symbol *pos, *n;
+
+	list_for_each_entry_safe(pos, n, &self->syms, node)
+		symbol__delete(pos);
+}
+
+static void dso__delete(struct dso *self)
+{
+	dso__delete_sections(self);
+	dso__delete_symbols(self);
+	free(self);
+}
+
+static void dso__insert_symbol(struct dso *self, struct symbol *sym)
+{
+	list_add_tail(&sym->node, &self->syms);
+}
+
+static struct symbol *dso__find_symbol(struct dso *self, uint64_t ip)
+{
+	if (self == NULL)
+		return NULL;
+
+	struct symbol *pos;
+
+	list_for_each_entry(pos, &self->syms, node)
+		if (ip >= pos->start && ip <= pos->end)
+			return pos;
+
+	return NULL;
+}
+
+static int dso__load(struct dso *self)
+{
+	/* FIXME */
+	return 0;
+}
+
+static size_t dso__fprintf(struct dso *self, FILE *fp)
+{
+	struct symbol *pos;
+	size_t ret = fprintf(fp, "dso: %s\n", self->name);
+
+	list_for_each_entry(pos, &self->syms, node)
+		ret += symbol__fprintf(pos, fp);
+
+	return ret;
+}
+
+static LIST_HEAD(dsos);
+static struct dso *kernel_dso;
+
+static void dsos__add(struct dso *dso)
+{
+	list_add_tail(&dso->node, &dsos);
+}
+
+static struct dso *dsos__find(const char *name)
+{
+	struct dso *pos;
+
+	list_for_each_entry(pos, &dsos, node)
+		if (strcmp(pos->name, name) == 0)
+			return pos;
+	return NULL;
+}
+
+static struct dso *dsos__findnew(const char *name)
+{
+	struct dso *dso = dsos__find(name);
+
+	if (dso == NULL) {
+		dso = dso__new(name);
+		if (dso != NULL && dso__load(dso) < 0)
+			goto out_delete_dso;
+
+		dsos__add(dso);
+	}
+
+	return dso;
+
+out_delete_dso:
+	dso__delete(dso);
+	return NULL;
+}
+
+static void dsos__fprintf(FILE *fp)
+{
+	struct dso *pos;
+
+	list_for_each_entry(pos, &dsos, node)
+		dso__fprintf(pos, fp);
+}
+
+static int load_kallsyms(void)
+{
+	kernel_dso = dso__new("[kernel]");
+	if (kernel_dso == NULL)
+		return -1;
+
+	FILE *file = fopen("/proc/kallsyms", "r");
+
+	if (file == NULL)
+		goto out_delete_dso;
+
+	char *line = NULL;
+	size_t n;
+
+	while (!feof(file)) {
+		unsigned long long start;
+		char c, symbf[4096];
+
+		if (getline(&line, &n, file) < 0)
+			break;
+
+		if (!line)
+			goto out_delete_dso;
+
+		if (sscanf(line, "%llx %c %s", &start, &c, symbf) == 3) {
+			struct symbol *sym = symbol__new(start, 0x1000000, symbf);
+
+			if (sym == NULL)
+				goto out_delete_dso;
+
+			dso__insert_symbol(kernel_dso, sym);
+		}
+	}
+
+	dsos__add(kernel_dso);
+	free(line);
+	fclose(file);
+	return 0;
+
+out_delete_dso:
+	dso__delete(kernel_dso);
+	return -1;
+}
+
+struct map {
+	struct list_head node;
+	uint64_t	 start;
+	uint64_t	 end;
+	uint64_t	 pgoff;
+	struct dso	 *dso;
+};
+
+static struct map *map__new(struct mmap_event *event)
+{
+	struct map *self = malloc(sizeof(*self));
+
+	if (self != NULL) {
+		self->start = event->start;
+		self->end   = event->start + event->len;
+		self->pgoff = event->pgoff;
+
+		self->dso = dsos__findnew(event->filename);
+		if (self->dso == NULL)
+			goto out_delete;
+	}
+	return self;
+out_delete:
+	free(self);
+	return NULL;
+}
+
+static size_t map__fprintf(struct map *self, FILE *fp)
+{
+	return fprintf(fp, " %lx-%lx %lx %s\n",
+		       self->start, self->end, self->pgoff, self->dso->name);
+}
+
+struct symhist {
+	struct list_head node;
+	struct dso	 *dso;
+	struct symbol	 *sym;
+	uint32_t	 count;
+	char		 level;
+};
+
+static struct symhist *symhist__new(struct symbol *sym, struct dso *dso,
+				    char level)
+{
+	struct symhist *self = malloc(sizeof(*self));
+
+	if (self != NULL) {
+		self->sym   = sym;
+		self->dso   = dso;
+		self->level = level;
+		self->count = 0;
+	}
+
+	return self;
+}
+
+static void symhist__delete(struct symhist *self)
+{
+	free(self);
+}
+
+static bool symhist__equal(struct symhist *self, struct symbol *sym,
+			   struct dso *dso, char level)
+{
+	return self->level == level && self->sym == sym && self->dso == dso;
+}
+
+static void symhist__inc(struct symhist *self)
+{
+	++self->count;
+}
+
+static size_t symhist__fprintf(struct symhist *self, FILE *fp)
+{
+	size_t ret = fprintf(fp, "[%c] ", self->level);
+
+	if (self->level != '.')
+		ret += fprintf(fp, "%s", self->sym->name);
+	else
+		ret += fprintf(fp, "%s: %s",
+			       self->dso ? self->dso->name : "<unknown",
+			       self->sym ? self->sym->name : "<unknown>");
+	return ret + fprintf(fp, ": %u\n", self->count);
+}
+
+struct thread {
+	struct list_head node;
+	struct list_head maps;
+	struct list_head symhists;
+	pid_t		 pid;
+	char		 *comm;
+};
+
+static struct thread *thread__new(pid_t pid)
+{
+	struct thread *self = malloc(sizeof(*self));
+
+	if (self != NULL) {
+		self->pid = pid;
+		self->comm = NULL;
+		INIT_LIST_HEAD(&self->maps);
+		INIT_LIST_HEAD(&self->symhists);
+	}
+
+	return self;
+}
+
+static void thread__insert_symhist(struct thread *self,
+				   struct symhist *symhist)
+{
+	list_add_tail(&symhist->node, &self->symhists);
+}
+
+static struct symhist *thread__symhists_find(struct thread *self,
+					     struct symbol *sym,
+					     struct dso *dso, char level)
+{
+	struct symhist *pos;
+
+	list_for_each_entry(pos, &self->symhists, node)
+		if (symhist__equal(pos, sym, dso, level))
+			return pos;
+
+	return NULL;
+}
+
+static int thread__symbol_incnew(struct thread *self, struct symbol *sym,
+				 struct dso *dso, char level)
+{
+	struct symhist *symhist = thread__symhists_find(self, sym, dso, level);
+
+	if (symhist == NULL) {
+		symhist = symhist__new(sym, dso, level);
+		if (symhist == NULL)
+			goto out_error;
+		thread__insert_symhist(self, symhist);
+	}
+
+	symhist__inc(symhist);
+	return 0;
+out_error:
+	return -ENOMEM;
+}
+
+static int thread__set_comm(struct thread *self, const char *comm)
+{
+	self->comm = strdup(comm);
+	return self->comm ? 0 : -ENOMEM;
+}
+
+static size_t thread__maps_fprintf(struct thread *self, FILE *fp)
+{
+	struct map *pos;
+	size_t ret = 0;
+
+	list_for_each_entry(pos, &self->maps, node)
+		ret += map__fprintf(pos, fp);
+
+	return ret;
+}
+
+static size_t thread__fprintf(struct thread *self, FILE *fp)
+{
+	struct symhist *pos;
+	int ret = fprintf(fp, "thread: %d %s\n", self->pid, self->comm);
+
+	list_for_each_entry(pos, &self->symhists, node)
+		ret += symhist__fprintf(pos, fp);
+
+	return ret;
+}
+
+static LIST_HEAD(threads);
+
+static void threads__add(struct thread *thread)
+{
+	list_add_tail(&thread->node, &threads);
+}
+
+static struct thread *threads__find(pid_t pid)
+{
+	struct thread *pos;
+
+	list_for_each_entry(pos, &threads, node)
+		if (pos->pid == pid)
+			return pos;
+	return NULL;
+}
+
+static struct thread *threads__findnew(pid_t pid)
+{
+	struct thread *thread = threads__find(pid);
+
+	if (thread == NULL) {
+		thread = thread__new(pid);
+		if (thread != NULL)
+			threads__add(thread);
+	}
+
+	return thread;
+}
+
+static void thread__insert_map(struct thread *self, struct map *map)
+{
+	list_add_tail(&map->node, &self->maps);
+}
+
+static struct map *thread__find_map(struct thread *self, uint64_t ip)
+{
+	if (self == NULL)
+		return NULL;
+
+	struct map *pos;
+
+	list_for_each_entry(pos, &self->maps, node)
+		if (ip >= pos->start && ip <= pos->end)
+			return pos;
+
+	return NULL;
+}
+
+static void threads__fprintf(FILE *fp)
+{
+	struct thread *pos;
+
+	list_for_each_entry(pos, &threads, node)
+		thread__fprintf(pos, fp);
+}
+
+#if 0
+static std::string resolve_user_symbol(int pid, uint64_t ip)
+{
+	std::string sym = "<unknown>";
+
+	maps_t &m = maps[pid];
+	maps_t::const_iterator mi = m.upper_bound(map(ip));
+	if (mi == m.end())
+		return sym;
+
+	ip -= mi->start + mi->pgoff;
+
+	symbols_t &s = dsos[mi->dso].syms;
+	symbols_t::const_iterator si = s.upper_bound(symbol(ip));
+
+	sym = mi->dso + ": <unknown>";
+
+	if (si == s.begin())
+		return sym;
+	si--;
+
+	if (si->start <= ip && ip < si->end)
+		sym = mi->dso + ": " + si->name;
+#if 0
+	else if (si->start <= ip)
+		sym = mi->dso + ": ?" + si->name;
+#endif
+
+	return sym;
+}
+#endif
+
+static void display_help(void)
+{
+	printf(
+	"Usage: perf-report [<options>]\n"
+	" -i file   --input=<file>      # input file\n"
+	);
+
+	exit(0);
+}
+
+static void process_options(int argc, char *argv[])
+{
+	int error = 0;
+
+	for (;;) {
+		int option_index = 0;
+		/** Options for getopt */
+		static struct option long_options[] = {
+			{"input",	required_argument,	NULL, 'i'},
+			{"no-user",	no_argument,		NULL, 'u'},
+			{"no-kernel",	no_argument,		NULL, 'k'},
+			{"no-hv",	no_argument,		NULL, 'h'},
+			{NULL,		0,			NULL,  0 }
+		};
+		int c = getopt_long(argc, argv, "+:i:kuh",
+				    long_options, &option_index);
+		if (c == -1)
+			break;
+
+		switch (c) {
+		case 'i': input_name			= strdup(optarg); break;
+		case 'k': show_mask &= ~SHOW_KERNEL; break;
+		case 'u': show_mask &= ~SHOW_USER; break;
+		case 'h': show_mask &= ~SHOW_HV; break;
+		default: error = 1; break;
+		}
+	}
+
+	if (error)
+		display_help();
+}
+
+int cmd_report(int argc, char **argv)
+{
+	unsigned long offset = 0;
+	unsigned long head = 0;
+	struct stat stat;
+	char *buf;
+	event_t *event;
+	int ret, rc = EXIT_FAILURE;
+	unsigned long total = 0;
+
+	page_size = getpagesize();
+
+	process_options(argc, argv);
+
+	input = open(input_name, O_RDONLY);
+	if (input < 0) {
+		perror("failed to open file");
+		exit(-1);
+	}
+
+	ret = fstat(input, &stat);
+	if (ret < 0) {
+		perror("failed to stat file");
+		exit(-1);
+	}
+
+	if (!stat.st_size) {
+		fprintf(stderr, "zero-sized file, nothing to do!\n");
+		exit(0);
+	}
+
+	if (load_kallsyms() < 0) {
+		perror("failed to open kallsyms");
+		return EXIT_FAILURE;
+	}
+
+remap:
+	buf = (char *)mmap(NULL, page_size * mmap_window, PROT_READ,
+			   MAP_SHARED, input, offset);
+	if (buf == MAP_FAILED) {
+		perror("failed to mmap file");
+		exit(-1);
+	}
+
+more:
+	event = (event_t *)(buf + head);
+
+	if (head + event->header.size >= page_size * mmap_window) {
+		unsigned long shift = page_size * (head / page_size);
+		int ret;
+
+		ret = munmap(buf, page_size * mmap_window);
+		assert(ret == 0);
+
+		offset += shift;
+		head -= shift;
+		goto remap;
+	}
+
+
+	if (!event->header.size) {
+		fprintf(stderr, "zero-sized event at file offset %ld\n", offset + head);
+		fprintf(stderr, "skipping %ld bytes of events.\n", stat.st_size - offset - head);
+		goto done;
+	}
+
+	head += event->header.size;
+
+	if (event->header.misc & PERF_EVENT_MISC_OVERFLOW) {
+		char level;
+		int show = 0;
+		struct dso *dso = NULL;
+		struct thread *thread = threads__findnew(event->ip.pid);
+
+		if (thread == NULL)
+			goto done;
+
+		if (event->header.misc & PERF_EVENT_MISC_KERNEL) {
+			show = SHOW_KERNEL;
+			level = 'k';
+			dso = kernel_dso;
+		} else if (event->header.misc & PERF_EVENT_MISC_USER) {
+			show = SHOW_USER;
+			level = '.';
+			struct map *map = thread__find_map(thread, event->ip.ip);
+			if (map != NULL)
+				dso = map->dso;
+		} else {
+			show = SHOW_HV;
+			level = 'H';
+		}
+
+		if (show & show_mask) {
+			struct symbol *sym = dso__find_symbol(dso, event->ip.ip);
+
+			if (thread__symbol_incnew(thread, sym, dso, level))
+				goto done;
+		}
+		total++;
+	} else switch (event->header.type) {
+	case PERF_EVENT_MMAP: {
+		struct thread *thread = threads__findnew(event->mmap.pid);
+		struct map *map = map__new(&event->mmap);
+
+		if (thread == NULL || map == NULL )
+			goto done;
+		thread__insert_map(thread, map);
+		break;
+	}
+	case PERF_EVENT_COMM: {
+		struct thread *thread = threads__findnew(event->comm.pid);
+
+		if (thread == NULL ||
+		    thread__set_comm(thread, event->comm.comm))
+			goto done;
+		break;
+	}
+	}
+
+	if (offset + head < stat.st_size)
+		goto more;
+
+	rc = EXIT_SUCCESS;
+done:
+	close(input);
+	//dsos__fprintf(stdout);
+	threads__fprintf(stdout);
+#if 0
+	std::map<std::string, int>::iterator hi = hist.begin();
+
+	while (hi != hist.end()) {
+		rev_hist.insert(std::pair<int, std::string>(hi->second, hi->first));
+		hist.erase(hi++);
+	}
+
+	std::multimap<int, std::string>::const_iterator ri = rev_hist.begin();
+
+	while (ri != rev_hist.end()) {
+		printf(" %5.2f %s\n", (100.0 * ri->first)/total, ri->second.c_str());
+		ri++;
+	}
+#endif
+	return rc;
+}
+
diff --git a/Documentation/perf_counter/builtin.h b/Documentation/perf_counter/builtin.h
index d32318a..5bfea57 100644
--- a/Documentation/perf_counter/builtin.h
+++ b/Documentation/perf_counter/builtin.h
@@ -16,6 +16,7 @@
 
 extern int cmd_help(int argc, const char **argv, const char *prefix);
 extern int cmd_record(int argc, const char **argv, const char *prefix);
+extern int cmd_report(int argc, const char **argv, const char *prefix);
 extern int cmd_stat(int argc, const char **argv, const char *prefix);
 extern int cmd_top(int argc, const char **argv, const char *prefix);
 extern int cmd_version(int argc, const char **argv, const char *prefix);
diff --git a/Documentation/perf_counter/command-list.txt b/Documentation/perf_counter/command-list.txt
index d15210a..4390292 100644
--- a/Documentation/perf_counter/command-list.txt
+++ b/Documentation/perf_counter/command-list.txt
@@ -1,6 +1,7 @@
 # List of known perf commands.
 # command name				category [deprecated] [common]
 perf-record                             mainporcelain common
+perf-report                             mainporcelain common
 perf-stat                               mainporcelain common
 perf-top                                mainporcelain common
 
diff --git a/Documentation/perf_counter/perf.c b/Documentation/perf_counter/perf.c
index 1d6d7aa..e8a8584 100644
--- a/Documentation/perf_counter/perf.c
+++ b/Documentation/perf_counter/perf.c
@@ -250,6 +250,7 @@
 	static struct cmd_struct commands[] = {
 		{ "help", cmd_help, 0 },
 		{ "record", cmd_record, 0 },
+		{ "report", cmd_report, 0 },
 		{ "stat", cmd_stat, 0 },
 		{ "top", cmd_top, 0 },
 		{ "version", cmd_version, 0 },