diff --git a/bench/benchgen.py b/bench/benchgen.py
new file mode 100644
index 0000000..33964dd
--- /dev/null
+++ b/bench/benchgen.py
@@ -0,0 +1,338 @@
+#!/usr/bin/env python
+
+# Copyright (C) 2015 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the 'License');
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an 'AS IS' BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""
+Generates storage benchmark from captured strace output.
+
+Currently assumes that all mmap'ed regions are resource accesses, and emulates as pread().
+
+Usage:
+$ adb shell strace -p `pid zygote` -o /data/local/tmp/trace -f -ff -y -ttt -e trace=file,desc,munmap
+$ adb pull /data/local/tmp/trace*
+$ python benchgen.py trace.*
+
+"""
+
+import re, sys, collections, traceback, argparse
+
+from operator import itemgetter
+from collections import defaultdict
+
+class Event:
+    def __init__(self, thread, time, call, args, ret):
+        self.thread = thread
+        self.time = time
+        self.call = call
+        self.args = args
+        self.ret = ret
+
+    def __repr__(self):
+        return "%s(%s)=%s" % (self.call, repr(self.args), self.ret)
+
+
+class File:
+    def __init__(self, name, ident):
+        self.name = name
+        self.ident = ident
+        self.size = 0
+
+    def __repr__(self):
+        return self.name
+
+
+events = []
+files = {}
+
+def find_file(name):
+    name = name.strip('<>"')
+    if name not in files:
+        files[name] = File(name, len(files))
+    return files[name]
+
+def extract_file(e, arg):
+    if "<" in arg:
+        fd, path = arg.split("<")
+        path = path.strip(">")
+        handle = "t%sf%s" % (e.thread, fd)
+        return (fd, find_file(path), handle)
+    else:
+        return (None, None, None)
+
+def parse_args(s):
+    args = []
+    arg = ""
+    esc = False
+    quot = False
+    for c in s:
+        if esc:
+            esc = False
+            arg += c
+            continue
+
+        if c == '"':
+            if quot:
+                quot = False
+                continue
+            else:
+                quot = True
+                continue
+
+        if c == '\\':
+            esc = True
+            continue
+
+        if c == ',' and not quot:
+            args.append(arg.strip())
+            arg = ""
+        else:
+            arg += c
+
+    args.append(arg.strip())
+    return args
+
+
+bufsize = 1048576
+interesting = ["mmap2","read","write","pread64","pwrite64","fsync","fdatasync","openat","close","lseek","_llseek"]
+
+re_event = re.compile(r"^([\d\.]+) (.+?)\((.+?)\) = (.+?)$")
+re_arg = re.compile(r'''((?:[^,"']|"[^"]*"|'[^']*')+)''')
+for fn in sys.argv[1:]:
+    with open(fn) as f:
+        thread = int(fn.split(".")[-1])
+        for line in f:
+            line = re_event.match(line)
+            if not line: continue
+
+            time, call, args, ret = line.groups()
+            if call not in interesting: continue
+            if "/data/" not in args: continue
+
+            time = float(time)
+            args = parse_args(args)
+            events.append(Event(thread, time, call, args, ret))
+
+
+with open("BenchmarkGen.h", 'w') as bench:
+    print >>bench, """/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+
+/******************************************************************
+ * THIS CODE WAS GENERATED BY benchgen.py, DO NOT MODIFY DIRECTLY *
+ ******************************************************************/
+
+
+#include <base/logging.h>
+
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/sendfile.h>
+#include <fcntl.h>
+
+#include <algorithm>
+#include <string>
+
+namespace android {
+namespace vold {
+
+static status_t BenchmarkRun() {
+"""
+
+    print >>bench, "char* buf = (char*) malloc(%d);" % (bufsize)
+
+    nread = 0
+    nwrite = 0
+    nsync = 0
+    events = sorted(events, key=lambda e: e.time)
+    active = set()
+    defined = set()
+    for e in events:
+        if e.call == "openat":
+            fd, f, handle = extract_file(e, e.ret)
+            if f:
+                active.add(handle)
+                if handle not in defined:
+                    print >>bench, "int ",
+                    defined.add(handle)
+                print >>bench, '%s = TEMP_FAILURE_RETRY(open("file%s", %s));' % (handle, f.ident, e.args[2])
+
+        elif e.call == "close":
+            fd, f, handle = extract_file(e, e.args[0])
+            if handle in active:
+                active.remove(handle)
+                print >>bench, 'TEMP_FAILURE_RETRY(close(%s));' % (handle)
+
+        elif e.call == "lseek":
+            fd, f, handle = extract_file(e, e.args[0])
+            if handle in active:
+                print >>bench, 'TEMP_FAILURE_RETRY(lseek(%s, %s, %s));' % (handle, e.args[1], e.args[2])
+
+        elif e.call == "_llseek":
+            fd, f, handle = extract_file(e, e.args[0])
+            if handle in active:
+                print >>bench, 'TEMP_FAILURE_RETRY(lseek(%s, %s, %s));' % (handle, e.args[1], e.args[3])
+
+        elif e.call == "read":
+            fd, f, handle = extract_file(e, e.args[0])
+            if handle in active:
+                # TODO: track actual file size instead of guessing
+                count = min(int(e.args[2]), bufsize)
+                f.size += count
+                print >>bench, 'TEMP_FAILURE_RETRY(read(%s, buf, %d));' % (handle, count)
+                nread += 1
+
+        elif e.call == "write":
+            fd, f, handle = extract_file(e, e.args[0])
+            if handle in active:
+                # TODO: track actual file size instead of guessing
+                count = min(int(e.args[2]), bufsize)
+                f.size += count
+                print >>bench, 'TEMP_FAILURE_RETRY(read(%s, buf, %d));' % (handle, count)
+                nwrite += 1
+
+        elif e.call == "pread64":
+            fd, f, handle = extract_file(e, e.args[0])
+            if handle in active:
+                f.size = max(f.size, int(e.args[2]) + int(e.args[3]))
+                count = min(int(e.args[2]), bufsize)
+                print >>bench, 'TEMP_FAILURE_RETRY(pread(%s, buf, %d, %s));' % (handle, count, e.args[3])
+                nread += 1
+
+        elif e.call == "pwrite64":
+            fd, f, handle = extract_file(e, e.args[0])
+            if handle in active:
+                f.size = max(f.size, int(e.args[2]) + int(e.args[3]))
+                count = min(int(e.args[2]), bufsize)
+                print >>bench, 'TEMP_FAILURE_RETRY(pwrite(%s, buf, %d, %s));' % (handle, count, e.args[3])
+                nwrite += 1
+
+        elif e.call == "fsync":
+            fd, f, handle = extract_file(e, e.args[0])
+            if handle in active:
+                print >>bench, 'TEMP_FAILURE_RETRY(fsync(%s));' % (handle)
+                nsync += 1
+
+        elif e.call == "fdatasync":
+            fd, f, handle = extract_file(e, e.args[0])
+            if handle in active:
+                print >>bench, 'TEMP_FAILURE_RETRY(fdatasync(%s));' % (handle)
+                nsync += 1
+
+        elif e.call == "mmap2":
+            fd, f, handle = extract_file(e, e.args[4])
+            if handle in active:
+                count = min(int(e.args[1]), bufsize)
+                offset = int(e.args[5], 0)
+                f.size = max(f.size, count + offset)
+                print >>bench, 'TEMP_FAILURE_RETRY(pread(%s, buf, %s, %s)); // mmap2' % (handle, count, offset)
+                nread += 1
+
+    for handle in active:
+        print >>bench, 'TEMP_FAILURE_RETRY(close(%s));' % (handle)
+
+    print >>bench, """
+free(buf);
+return 0;
+}
+
+static status_t CreateFile(const char* name, size_t len) {
+    status_t res = -1;
+    int in = -1;
+    int out = -1;
+
+    if ((in = TEMP_FAILURE_RETRY(open("/dev/zero", O_RDONLY))) < 0) {
+        PLOG(ERROR) << "Failed to open";
+        goto done;
+    }
+    if ((out = TEMP_FAILURE_RETRY(open(name, O_WRONLY|O_CREAT|O_TRUNC))) < 0) {
+        PLOG(ERROR) << "Failed to open " << name;
+        goto done;
+    }
+
+    char buf[65536];
+    while (len > 0) {
+        int n = read(in, buf, std::min(len, sizeof(buf)));
+        if (write(out, buf, n) != n) {
+            PLOG(ERROR) << "Failed to write";
+            goto done;
+        }
+        len -= n;
+    }
+
+    res = 0;
+done:
+    close(in);
+    close(out);
+    return res;
+}
+
+static status_t BenchmarkCreate() {
+status_t res = 0;
+res |= CreateFile("stub", 0);
+"""
+    for f in files.values():
+        print >>bench, 'res |= CreateFile("file%s", %d);' % (f.ident, f.size)
+
+    print >>bench, """
+return res;
+}
+
+static status_t BenchmarkDestroy() {
+status_t res = 0;
+res |= unlink("stub");
+"""
+    for f in files.values():
+        print >>bench, 'res |= unlink("file%s");' % (f.ident)
+
+    print >>bench, """
+return res;
+}
+
+static std::string BenchmarkIdent() {"""
+    print >>bench, """return "r%d:w%d:s%d";""" % (nread, nwrite, nsync)
+    print >>bench, """}
+
+}  // namespace vold
+}  // namespace android
+"""
+
+
+size = sum([ f.size for f in files.values() ])
+print "Found", len(files), "data files accessed, total size", (size/1024), "kB"
+
+types = defaultdict(int)
+for e in events:
+    types[e.call] += 1
+
+print "Found syscalls:"
+for t, n in types.iteritems():
+    print str(n).rjust(8), t
+
+print