diff mbox

KVM test: KSM (kernel shared memory) overcommit test

Message ID 1321581202.1383421265818432502.JavaMail.root@zmail05.collab.prod.int.phx2.redhat.com (mailing list archive)
State New, archived
Headers show

Commit Message

Jiri Zupka Feb. 10, 2010, 4:13 p.m. UTC
None
diff mbox

Patch

diff --git a/client/tests/kvm/kvm_test_utils.py b/client/tests/kvm/kvm_test_utils.py
index 02ec0cf..7d96d6e 100644
--- a/client/tests/kvm/kvm_test_utils.py
+++ b/client/tests/kvm/kvm_test_utils.py
@@ -22,7 +22,8 @@  More specifically:
 """
 
 import time, os, logging, re, commands
-from autotest_lib.client.common_lib import utils, error
+from autotest_lib.client.common_lib import error
+from autotest_lib.client.bin import utils
 import kvm_utils, kvm_vm, kvm_subprocess
 
 
@@ -203,3 +204,36 @@  def get_time(session, time_command, time_filter_re, time_format):
     s = re.findall(time_filter_re, s)[0]
     guest_time = time.mktime(time.strptime(s, time_format))
     return (host_time, guest_time)
+
+
+def get_memory_info(lvms):
+    """
+    Get memory information from host and guests in format:
+    Host: memfree = XXXM; Guests memsh = {XXX,XXX,...}
+
+    @params lvms: List of VM objects
+    @return: String with memory info report
+    """
+    if not isinstance(lvms, list):
+        raise error.TestError("Invalid list passed to get_stat: %s " % lvms)
+
+    try:
+        meminfo = "Host: memfree = "
+        meminfo += str(int(utils.freememtotal()) / 1024) + "M; "
+        meminfo += "swapfree = "
+        mf = int(utils.read_from_meminfo("SwapFree")) / 1024
+        meminfo += str(mf) + "M; "
+    except Exception, e:
+        raise error.TestFail("Could not fetch host free memory info, "
+                             "reason: %s" % e)
+
+    meminfo += "Guests memsh = {"
+    for vm in lvms:
+        shm = vm.get_shared_meminfo()
+        if shm is None:
+            raise error.TestError("Could not get shared meminfo from "
+                                  "VM %s" % vm)
+        meminfo += "%dM; " % shm
+    meminfo = meminfo[0:-2] + "}"
+
+    return meminfo
diff --git a/client/tests/kvm/kvm_utils.py b/client/tests/kvm/kvm_utils.py
index df26a77..c9cd2e1 100644
--- a/client/tests/kvm/kvm_utils.py
+++ b/client/tests/kvm/kvm_utils.py
@@ -713,6 +713,22 @@  def generate_random_string(length):
     return str
 
 
+def generate_tmp_file_name(file, ext=None, dir='/tmp/'):
+    """
+    Returns a temporary file name. The file is not created.
+    """
+    while True:
+        file_name = (file + '-' + time.strftime("%Y%m%d-%H%M%S-") +
+                     generate_random_string(4))
+        if ext:
+            file_name += '.' + ext
+        file_name = os.path.join(dir, file_name)
+        if not os.path.exists(file_name):
+            break
+
+    return file_name
+
+
 def format_str_for_message(str):
     """
     Format str so that it can be appended to a message.
diff --git a/client/tests/kvm/kvm_vm.py b/client/tests/kvm/kvm_vm.py
index 6731927..5790dff 100755
--- a/client/tests/kvm/kvm_vm.py
+++ b/client/tests/kvm/kvm_vm.py
@@ -760,6 +760,23 @@  class VM:
         return self.process.get_pid()
 
 
+    def get_shared_meminfo(self):
+        """
+        Returns the VM's shared memory information.
+
+        @return: Shared memory used by VM (MB)
+        """
+        if self.is_dead():
+            logging.error("Could not get shared memory info from dead VM.")
+            return None
+
+        cmd = "cat /proc/%d/statm" % self.params.get('pid_' + self.name)
+        shm = int(os.popen(cmd).readline().split()[2])
+        # statm stores informations in pages, translate it to MB
+        shm = shm * 4 / 1024
+        return shm
+
+
     def remote_login(self, nic_index=0, timeout=10):
         """
         Log into the guest via SSH/Telnet/Netcat.
diff --git a/client/tests/kvm/scripts/allocator.py b/client/tests/kvm/scripts/allocator.py
new file mode 100644
index 0000000..e0b8c75
--- /dev/null
+++ b/client/tests/kvm/scripts/allocator.py
@@ -0,0 +1,230 @@ 
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+"""
+Auxiliary script used to allocate memory on guests.
+
+@copyright: 2008-2009 Red Hat Inc.
+@author: Jiri Zupka (jzupka@redhat.com)
+"""
+
+
+import os, array, sys, struct, random, copy, inspect, tempfile, datetime
+
+PAGE_SIZE = 4096 # machine page size
+
+
+class MemFill(object):
+    """
+    Fills guest memory according to certain patterns.
+    """
+    def __init__(self, mem, static_value, random_key):
+        """
+        Constructor of MemFill class.
+
+        @param mem: Amount of test memory in MB.
+        @param random_key: Seed of random series used for fill up memory.
+        @param static_value: Value used to fill all memory.
+        """
+        if (static_value < 0 or static_value > 255):
+            print ("FAIL: Initialization static value"
+                   "can be only in range (0..255)")
+            return
+
+        self.tmpdp = tempfile.mkdtemp()
+        ret_code = os.system("mount -o size=%dM tmpfs %s -t tmpfs" %
+                             ((mem + 25), self.tmpdp))
+        if ret_code != 0:
+            if os.getuid() != 0:
+                print ("FAIL: Unable to mount tmpfs "
+                       "(likely cause: you are not root)")
+            else:
+                print "FAIL: Unable to mount tmpfs"
+        else:
+            self.f = tempfile.TemporaryFile(prefix='mem', dir=self.tmpdp)
+            self.allocate_by = 'L'
+            self.npages = (mem * 1024 * 1024) / PAGE_SIZE
+            self.random_key = random_key
+            self.static_value = static_value
+            print "PASS: Initialization"
+
+
+    def __del__(self):
+        if (os.path.ismount(self.tmpdp)):
+            self.f.close()
+            os.system("umount %s" % (self.tmpdp))
+
+
+    def compare_page(self, original, inmem):
+        """
+        Compare pages of memory.
+
+        @param original: Data that was expected to be in memory.
+        @param inmem: Data in memory.
+        """
+        for ip in range(PAGE_SIZE / original.itemsize):
+            if (not original[ip] == inmem[ip]): # find which item is wrong
+                originalp = array.array("B")
+                inmemp = array.array("B")
+                originalp.fromstring(original[ip:ip+1].tostring())
+                inmemp.fromstring(inmem[ip:ip+1].tostring())
+                for ib in range(len(originalp)): # find wrong byte in item
+                    if not (originalp[ib] == inmemp[ib]):
+                        position = (self.f.tell() - PAGE_SIZE + ip *
+                                    original.itemsize + ib)
+                        print ("Mem error on position %d wanted 0x%Lx and is "
+                               "0x%Lx" % (position, originalp[ib], inmemp[ib]))
+
+
+    def value_page(self, value):
+        """
+        Create page filled by value.
+
+        @param value: String we want to fill the page with.
+        @return: return array of bytes size PAGE_SIZE.
+        """
+        a = array.array("B")
+        for i in range(PAGE_SIZE / a.itemsize):
+            try:
+                a.append(value)
+            except:
+                print "FAIL: Value can be only in range (0..255)"
+        return a
+
+
+    def random_page(self, seed):
+        """
+        Create page filled by static random series.
+
+        @param seed: Seed of random series.
+        @return: Static random array series.
+        """
+        random.seed(seed)
+        a = array.array(self.allocate_by)
+        for i in range(PAGE_SIZE / a.itemsize):
+            a.append(random.randrange(0, sys.maxint))
+        return a
+
+
+    def value_fill(self, value=None):
+        """
+        Fill memory page by page, with value generated with value_page.
+
+        @param value: Parameter to be passed to value_page. None to just use
+                what's on the attribute static_value.
+        """
+        self.f.seek(0)
+        if value is None:
+            value = self.static_value
+        page = self.value_page(value)
+        for pages in range(self.npages):
+            page.tofile(self.f)
+        print "PASS: Mem value fill"
+
+
+    def value_check(self):
+        """
+        Check memory to see if data is correct.
+
+        @return: if data in memory is correct return PASS
+                else print some wrong data and return FAIL
+        """
+        self.f.seek(0)
+        e = 2
+        failure = False
+        page = self.value_page(self.static_value)
+        for pages in range(self.npages):
+            pf = array.array("B")
+            pf.fromfile(self.f, PAGE_SIZE / pf.itemsize)
+            if not (page == pf):
+                failure = True
+                self.compare_page(page, pf)
+                e = e - 1
+                if e == 0:
+                    break
+        if failure:
+            print "FAIL: value verification"
+        else:
+            print "PASS: value verification"
+
+
+    def static_random_fill(self, n_bytes_on_end=PAGE_SIZE):
+        """
+        Fill memory by page with static random series with added special value
+        on random place in pages.
+
+        @param n_bytes_on_end: how many bytes on the end of page can be changed.
+        @return: PASS.
+        """
+        self.f.seek(0)
+        page = self.random_page(self.random_key)
+        random.seed(self.random_key)
+        p = copy.copy(page)
+
+        t_start = datetime.datetime.now()
+        for pages in range(self.npages):
+            rand = random.randint(((PAGE_SIZE / page.itemsize) - 1) -
+                                  (n_bytes_on_end / page.itemsize),
+                                  (PAGE_SIZE/page.itemsize) - 1)
+            p[rand] = pages
+            p.tofile(self.f)
+            p[rand] = page[rand]
+
+        t_end = datetime.datetime.now()
+        delta = t_end - t_start
+        milisec = delta.microseconds / 1e3 + delta.seconds * 1e3
+        print "PASS: filling duration = %Ld ms" % milisec
+
+
+    def static_random_verify(self, n_bytes_on_end=PAGE_SIZE):
+        """
+        Check memory to see if it contains correct contents.
+
+        @return: if data in memory is correct return PASS
+                else print some wrong data and return FAIL.
+        """
+        self.f.seek(0)
+        e = 2
+        page = self.random_page(self.random_key)
+        random.seed(self.random_key)
+        p = copy.copy(page)
+        failure = False
+        for pages in range(self.npages):
+            rand = random.randint(((PAGE_SIZE/page.itemsize) - 1) -
+                                  (n_bytes_on_end/page.itemsize),
+                                  (PAGE_SIZE/page.itemsize) - 1)
+            p[rand] = pages
+            pf = array.array(self.allocate_by)
+            pf.fromfile(self.f, PAGE_SIZE / pf.itemsize)
+            if not (p == pf):
+                failure = True
+                self.compare_page(p, pf)
+                e = e - 1
+                if e == 0:
+                    break
+            p[rand] = page[rand]
+        if failure:
+            print "FAIL: Random series verification"
+        else:
+            print "PASS: Random series verification"
+
+
+def die():
+    """
+    Quit allocator.
+    """
+    exit(0)
+
+
+def main():
+    """
+    Main (infinite) loop of allocator.
+    """
+    print "PASS: Start"
+    end = False
+    while (not end):
+        str = raw_input()
+        exec str
+
+
+if __name__ == "__main__":
+    main()
diff --git a/client/tests/kvm/tests/ksm_overcommit.py b/client/tests/kvm/tests/ksm_overcommit.py
new file mode 100644
index 0000000..6e8f412
--- /dev/null
+++ b/client/tests/kvm/tests/ksm_overcommit.py
@@ -0,0 +1,582 @@ 
+import logging, time, random, string, math, os, tempfile
+from autotest_lib.client.common_lib import error
+from autotest_lib.client.bin import utils
+import kvm_subprocess, kvm_test_utils, kvm_utils, kvm_preprocessing
+
+
+def run_ksm_overcommit(test, params, env):
+    """
+    Test how KSM (Kernel Shared Memory) act with more than physical memory is
+    used. In second part is also tested, how KVM can handle the situation,
+    when the host runs out of memory (it is expected to pause the guest system,
+    wait until some process returns the memory and bring the guest back to life)
+
+
+
+    @param test: kvm test object.
+    @param params: Dictionary with test parameters.
+    @param env: Dictionary with the test wnvironment.
+    """
+
+    def initialize_guests():
+        """
+        Initialize guests (fill their memories with specified patterns).
+        """
+        logging.info("Starting phase 1: filling with 0")
+        logging.info("Preparing the guests and fill in pages with 0")
+        for session in lsessions:
+            vm = lvms[lsessions.index(session)]
+
+            ret = session.get_command_status("swapoff -a", timeout=300)
+            if ret is None or ret:
+                raise error.TestFail("Failed to swapoff on VM %s" % vm.name)
+
+            # Start the allocator
+            session.sendline("python /tmp/allocator.py")
+            (ret, data) = session.read_until_last_line_matches(
+                                                              ["PASS:","FAIL:"],
+                               	                              60 * perf_ratio)
+            if ret is None or ret == 1:
+                raise error.TestFail("Could not run vksmd in %s errno: %s\n"
+                                     "Output:\n%s" % (vm.name, ret, data))
+
+        # Set allocator keys
+        for i in range(0, vmsc):
+            vm = lvms[i]
+
+            lsessions[i].sendline("mem = MemFill(%d, %s, %s)" %
+                                  (ksm_size, skeys[i], dkeys[i]))
+
+            (match, data) = lsessions[i].read_until_last_line_matches(
+                                                              ["PASS:","FAIL:"],
+                                                              60 * perf_ratio)
+            if match == 1 or match is None:
+                raise error.TestFail("Could not allocate memory on guest %s\n"
+                                     "Output:\n%s" % (vm.name, data))
+
+            lsessions[i].sendline("mem.value_fill(%d)"% (skeys[0]))
+            (match,data) = lsessions[i].read_until_last_line_matches(
+                                                              ["PASS:","FAIL:"],
+                                                              120 * perf_ratio)
+            if match == 1 or match is None:
+                raise error.TestFail("Could not allocate memory on guest %s\n"
+                                     "Output: %s" % (vm.name, data))
+
+            # Let kksmd works (until shared mem reaches expected value)
+            shm = 0
+            i = 0
+            while shm < ksm_size:
+                if i > 64:
+                    logging.info(kvm_test_utils.get_memory_info(lvms))
+                    raise error.TestError("SHM didn't merge the memory until "
+                                          "the DL on guest: %s"% (vm.name))
+                st = ksm_size / 200 * perf_ratio
+                logging.debug("Sleep (%d)" % st)
+                time.sleep(st)
+                shm = vm.get_shared_meminfo()
+                i = i + 1
+
+        # Keep some reserve
+        time.sleep(ksm_size / 200 * perf_ratio)
+
+        logging.info(kvm_test_utils.get_memory_info(lvms))
+        logging.info("Phase 1 => passed")
+
+
+    def separate_first_guest():
+        """
+        Separate memory of the first guest by generating special random series
+        """
+        logging.info("Starting phase 2: Split the pages on the first guest")
+
+        lsessions[0].sendline("mem.static_random_fill()")
+
+        (match, data) = lsessions[0].read_until_last_line_matches(
+                                                              ["PASS:","FAIL:"],
+                                                              120 * perf_ratio)
+        if match == 1:
+            raise error.TestFail("Could not fill memory by random on guest %s"
+                                 "\nOutput:\n%s" % (vm.name, data))
+
+        if match == None:
+            raise error.TestFail("Generating random series timeout on "
+                                 "guest %s" % vm.name)
+
+        r_msg = data.splitlines()[-1]
+        logging.debug("Return message of static_random_fill: %s", r_msg)
+        out = int(r_msg.split()[4])
+        logging.info("PERFORMANCE: %dMB * 1000 / %dms = %dMB/s", ksm_size, out,
+                     (ksm_size * 1000 / out))
+        logging.info(kvm_test_utils.get_memory_info(lvms))
+        logging.info("Phase 2 => passed")
+
+
+    def split_guest():
+        """
+        Sequential split of pages on guests up to memory limit
+        """
+        logging.info("Starting phase 3a: Sequentional split of pages on "
+                     "guests up to memory limit")
+        last_vm = 0
+        session = None
+        vm = None
+        for i in range(1, vmsc):
+            vm = lvms[i]
+            session = lsessions[i]
+            session.sendline("mem.static_random_fill()")
+            
+            out = ""
+            try:
+                while not out.startswith("PASS") and not out.startswith("FAIL"):
+                    free_mem = int(utils.read_from_meminfo("MemFree"))
+                    if (ksm_swap):
+                        free_mem = (free_mem +
+                                    int(utils.read_from_meminfo("SwapFree")))
+                    logging.debug("FreeMem = %d" % (free_mem))
+                    # We need to keep some memory for python to run.
+
+                    if (free_mem < 64000) or (ksm_swap and free_mem < (450000*perf_ratio)):
+                        vm.send_monitor_cmd('stop')
+                        for j in range(0, i):
+                            lvms[j].destroy(gracefully = False)
+                        time.sleep(20)
+                        vm.send_monitor_cmd('c')
+                        logging.debug("Only %s free memory, killing 0 - %d hosts" %
+                                      (free_mem, (i-1)))
+                        last_vm = i
+                        break
+                    out = session.read_nonblocking(0.1)
+            except OSError, (err):
+		vm.send_monitor_cmd('stop')
+		for j in range(0, i):
+			lvms[j].destroy(gracefully = False)
+		time.sleep(20)
+		vm.send_monitor_cmd('c')
+		logging.debug("Only %s free memory, killing 0 - %d hosts" %
+			 	  (free_mem, (i-1)))
+		last_vm = i
+
+            if last_vm != 0:
+                break
+
+        logging.info("Memory filled by the guest %s" % (vm.name))
+        logging.info("Phase 3a => passed")
+
+        # Check if memory in max loading guest is right
+        logging.info("Starting phase 3b")
+
+        # Kill rest of machines
+        for i in range(last_vm + 1, vmsc):
+            lsessions[i].close()
+            if i == (vmsc - 1):
+                logging.info(kvm_test_utils.get_memory_info([lvms[i]]))
+            lvms[i].destroy(gracefully = False)
+
+        # Verify last machine with randomly generated memory
+        session.sendline("mem.static_random_verify()")
+        (match, data) = session.read_until_last_line_matches(
+                                                  ["PASS:","FAIL:"],
+                                                  (mem / 200 * 50 * perf_ratio))
+        if (match == 1):
+            raise error.TestError("Memory error dump: %s" % data)
+        logging.info(kvm_test_utils.get_memory_info([lvms[last_vm]]))
+        (status,data) = lsessions[i].get_command_status_output("die()",20)
+        lvms[last_vm].destroy(gracefully = False)
+        logging.info("Phase 3b => passed")
+
+
+    def split_parallel():
+        """
+        Parallel page spliting
+        """
+        logging.info("Phase 1: parallel page spliting")
+        # We have to wait until allocator is finished (it waits 5 seconds to
+        # clean the socket
+
+        session = lsessions[0]
+        vm = lvms[0]
+        for i in range(1,max_alloc):
+            lsessions.append(kvm_utils.wait_for(vm.remote_login, 360, 0, 2))
+            if not lsessions[i]:
+                raise error.TestFail("Could not log into guest %s" %
+                                     lvms[i].name)
+
+        ret = session.get_command_status("swapoff -a", timeout=300)
+        if ret is None or ret:
+            raise error.TestFail("Failed to swapoff in the %s" % (vm.name))
+
+        for i in range(0, max_alloc):
+            lsessions[i].sendline("python /tmp/allocator.py")
+            (ret,data) = lsessions[i].read_until_last_line_matches(
+                                        ["PASS:","FAIL:"], (60 * perf_ratio))
+            if ret == None:
+                raise error.TestFail("Could not run vksmd in guest %s" %
+                                     vm.name)
+            if ret == 1:
+                raise error.TestFail("Could not run allocator in %s errno: %d"
+                                     "\nOutput:\n%s" % (vm.name, ret, data))
+
+        logging.info("Phase 4a: Simultaneous merging")
+        for i in range(0, max_alloc):
+            logging.info("Memory to guest allocator = %dMB" %
+                         (ksm_size / max_alloc))
+            lsessions[i].sendline("mem = MemFill(%d, %s, %s)" %
+                                  ((ksm_size / max_alloc), skeys[i], dkeys[i]))
+
+        for i in range(0, max_alloc):
+            (match, data) = lsessions[i].read_until_last_line_matches(
+                                        ["PASS:","FAIL:"], (60 * perf_ratio))
+            if match == 1:
+                raise error.TestFail("Could not allocate memory on guest %s"
+                                     "\nOutput:\n%s" % (vm.name, data))
+
+        for i in range(0, max_alloc):
+            lsessions[i].sendline("mem.value_fill(%d)" % (skeys[0]))
+
+        for i in range(0, max_alloc):
+            (match,data) = lsessions[i].read_until_last_line_matches(
+                                        ["PASS:","FAIL:"], (90 * perf_ratio))
+            if match == 1:
+                raise error.TestFail("Could not allocate memory on guest %s"
+                                     "\nOutput:\n%s" % (vm.name, data))
+        # Wait until kksmd merges the pages (3 * ksm_size / 3)
+        shm = 0
+        i = 0
+        while shm < ksm_size:
+            if i > 64:
+                logging.info(kvm_test_utils.get_memory_info(lvms))
+                raise error.TestError("SHM didn't merge the memory until DL")
+            logging.debug("Sleep(%d)" % (ksm_size / 200 * perf_ratio))
+            time.sleep(ksm_size / 200 * perf_ratio)
+            shm = vm.get_shared_meminfo()
+            i = i + 1
+        logging.info(kvm_test_utils.get_memory_info([vm]))
+
+        logging.info("Phases 4b: Simultaneous spliting")
+        # Actual splitting
+        for i in range(0, max_alloc):
+            lsessions[i].sendline("mem.static_random_fill()")
+
+        for i in range(0, max_alloc):
+            (match,data) = lsessions[i].read_until_last_line_matches(
+                                        ["PASS:","FAIL:"], (90 * perf_ratio))
+            if match == 1:
+                raise error.TestFail("Could not fill memory with random "
+                                     "pattern on guest %s\n"
+                                     "Output:\n%s" % (vm.name, data))
+
+            if match == None:
+                raise error.TestFail("Generating rantime.sleepdom series timeout on "
+                                     "guest %s" % (vm.name))
+
+            data = data.splitlines()[-1]
+            logging.debug(data)
+            out = int(data.split()[4])
+            logging.info("PERFORMANCE: %dMB * 1000 / %dms = %dMB/s" %
+                         ((ksm_size / max_alloc), out,
+                          (ksm_size * 1000 / out / max_alloc)))
+        logging.info(kvm_test_utils.get_memory_info([vm]))
+
+        logging.info("Phase 4c: Simultaneous verification")
+        for i in range(0, max_alloc):
+            lsessions[i].sendline("mem.static_random_verify()")
+        for i in range(0, max_alloc):
+            (match, data) = lsessions[i].read_until_last_line_matches(
+                                                  ["PASS:","FAIL:"],
+                                                  (mem / 200 * 50 * perf_ratio))
+            if (match == 1):
+                raise error.TestError("Memory error dump: %s" % data)
+
+        logging.info("Phases 4d: Simultaneous merging")
+
+        # Actual splitting
+        for i in range(0, max_alloc):
+            lsessions[i].sendline("mem.value_fill(%d)" % (skeys[0]))
+        for i in range(0, max_alloc):
+            (match, data) = lsessions[i].read_until_last_line_matches(
+                                                             ["PASS:","FAIL:"],
+                                                             (120 * perf_ratio))
+            if match == 1:
+                raise error.TestFail("Could not fill memory by random on guest "
+                                     "%s\nOutput:\n%s" % vm.name)
+        logging.info(kvm_test_utils.get_memory_info([vm]))
+
+        logging.info("Phase 4e: Simultaneous verification")
+        for i in range(0, max_alloc):
+            lsessions[i].sendline("mem.value_fill(%d)" % (skeys[0]))
+        for i in range(0, max_alloc):
+            (match, data) = lsessions[i].read_until_last_line_matches(
+                                                  ["PASS:","FAIL:"],
+                                                  (mem / 200 * 50 * perf_ratio))
+            if match == 1:
+                raise error.TestError("Memory error dump: %s" % data)
+
+        logging.info("Phases 4f: Simultaneous spliting last 96B")
+
+        # Actual splitting
+        for i in range(0, max_alloc):
+            lsessions[i].sendline("mem.static_random_fill(96)")
+
+        for i in range(0, max_alloc):
+            (match, data) = lsessions[i].read_until_last_line_matches(
+                                                              ["PASS:","FAIL:"],
+                                                              (60 * perf_ratio))
+            if match == 1:
+                raise error.TestFail("Could not fill memory by zero on guest "
+                                     "%s\nOutput:\n%s" % (vm.name))
+
+            if match == None:
+                raise error.TestFail("Generating random series timeout on "
+                                     "guest %s" % vm.name)
+
+            data = data.splitlines()[-1]
+            out = int(data.split()[4])
+            logging.info("PERFORMANCE: %dMB * 1000 / %dms = %dMB/s",
+                         ksm_size/max_alloc, out,
+                         (ksm_size * 1000 / out / max_alloc))
+        logging.info(kvm_test_utils.get_memory_info([vm]))
+
+        logging.info("Phase 4g: Simultaneous verification last 96B")
+        for i in range(0, max_alloc):
+            lsessions[i].sendline("mem.static_random_verify(96)")
+        for i in range(0, max_alloc):
+            (match,data) = lsessions[i].read_until_last_line_matches(
+                                                  ["PASS:","FAIL:"],
+                                                  (mem / 200 * 50 * perf_ratio))
+            if (match == 1):
+                raise error.TestError("Memory error dump: %s" % data)
+
+        logging.info(kvm_test_utils.get_memory_info([vm]))
+
+        logging.info("Phase 4 => passed")
+
+        # Clean up
+        for i in range(0, max_alloc):
+            lsessions[i].get_command_status_output("die()", 20)
+        session.close()
+        vm.destroy(gracefully = False)
+
+
+    # Main test code
+    logging.info("Starting phase 0: Initialization")
+    # host_reserve: mem reserve kept for the host system to run
+    host_reserve = 256
+    # guest_reserve: mem reserve which is not used by allocator on the
+    # guests
+    guest_reserve = 256
+    max_vms = params.get("max_vms")
+    if max_vms:
+        max_vms = int(max_vms)
+    else:
+        max_vms = 2
+
+    overcommit = params.get("ksm_overcommit_ratio")
+    if overcommit:
+        overcommit = float(overcommit)
+    else:
+        overcommit = 2.0
+
+    max_alloc = params.get("ksm_parallel_ratio")
+    if max_alloc:
+        max_alloc = int(max_alloc)
+    else:
+        max_alloc = 1
+
+    # vmsc: count of all used VMs
+    vmsc = int(overcommit) + 1
+    vmsc = max(vmsc, max_vms)
+
+    if (params['ksm_test_size'] == "serial"):
+        max_alloc = vmsc
+
+    host_mem = (int(utils.memtotal()) / 1024 - host_reserve)
+
+    ksm_swap = False
+    if params.get("ksm_swap") == "yes":
+        ksm_swap = True
+
+    # Performance ratio
+    perf_ratio = params.get("ksm_perf_ratio")
+    if perf_ratio:
+        perf_ratio = float(perf_ratio)
+    else:
+        perf_ratio = 1
+
+    if (params['ksm_test_size'] == "parallel"):
+        vmsc = 1
+        overcommit = 1
+        mem = host_mem
+        # 32bit system adjustment
+        if not params['image_name'].endswith("64"):
+            logging.debug("Probably i386 guest architecture, "
+                          "max allocator mem = 2G")
+            # Guest can have more than 2G but
+            # kvm mem + 1MB (allocator itself) can't
+            if (host_mem > 3100):
+                mem = 3100
+
+        if os.popen("uname -i").readline().startswith("i386"):
+            logging.debug("Host is i386 architecture, max guest mem is 2G")
+            # Guest system with qemu overhead (64M) can't have more than 2G
+            if mem > 3100 - 64:
+                mem = 3100 - 64
+
+    else:
+        # mem: Memory of the guest systems. Maximum must be less than
+        # host's physical ram
+        mem = int(overcommit * host_mem / vmsc)
+
+        # 32bit system adjustment
+        if not params['image_name'].endswith("64"):
+            logging.debug("Probably i386 guest architecture, "
+                          "max allocator mem = 2G")
+            # Guest can have more than 2G but
+            # kvm mem + 1MB (allocator itself) can't
+            if mem - guest_reserve - 1 > 3100:
+                vmsc = int(math.ceil((host_mem * overcommit) /
+                                     (3100 + guest_reserve)))
+                mem = int(math.floor(host_mem * overcommit / vmsc))
+
+        if os.popen("uname -i").readline().startswith("i386"):
+            logging.debug("Host is i386 architecture, max guest mem is 2G")
+            # Guest system with qemu overhead (64M) can't have more than 2G
+            if mem > 3100 - 64:
+                vmsc = int(math.ceil((host_mem * overcommit) /
+                                     (3100 - 64.0)))
+                mem = int(math.floor(host_mem * overcommit / vmsc))
+
+    logging.debug("Checking KSM status...")
+    ksm_flag = 0
+    for line in os.popen('ksmctl info').readlines():
+        if line.startswith('flags'):
+            ksm_flag = int(line.split(' ')[1].split(',')[0])
+    if int(ksm_flag) != 1:
+        logging.info("KSM module is not loaded! Trying to load module and "
+                     "start ksmctl...")
+        try:
+            utils.run("modprobe ksm")
+            utils.run("ksmctl start 5000 100")
+        except error.CmdError, e:
+            raise error.TestFail("Failed to load KSM: %s" % e)
+    logging.debug("KSM module loaded and ksmctl started")
+
+    logging.info("overcommit = %f", overcommit)
+    logging.info("true overcommit = %f ", (float(vmsc * mem) /
+                                           float(host_mem)))
+    logging.info("host mem = %dM", host_mem)
+    logging.info("mem = %dM", mem)
+    logging.info("using swap = %s", ksm_swap)
+    swap = int(utils.read_from_meminfo("SwapTotal")) / 1024
+    logging.info("swap = %dM", swap)
+    logging.info("max_vms = %d", max_vms)
+    logging.info("vmsc = %d", vmsc)
+    logging.info("performance_ratio = %f", perf_ratio)
+
+    # Generate unique keys for random series
+    skeys = []
+    dkeys = []
+    for i in range(0, max(vmsc, max_alloc)):
+        key = random.randrange(0, 255)
+        while key in skeys:
+            key = random.randrange(0, 255)
+        skeys.append(key)
+
+        key = random.randrange(0, 999)
+        while key in dkeys:
+            key = random.randrange(0, 999)
+        dkeys.append(key)
+
+    lvms = []
+    lsessions = []
+
+    # As we don't know the number and memory amount of VMs in advance,
+    # we need to specify and create them here (FIXME: not a nice thing)
+    vm_name = params.get("main_vm")
+    params['mem'] = mem
+    params['vms'] = vm_name
+    # Associate pidfile name
+    params['pid_' + vm_name] = kvm_utils.generate_tmp_file_name(vm_name,
+                                                                'pid')
+    if not params.get('extra_params'):
+        params['extra_params'] = ' '
+    params['extra_params_' + vm_name] = params.get('extra_params')
+    params['extra_params_' + vm_name] += (" -pidfile %s" %
+                                          (params.get('pid_' + vm_name)))
+    params['extra_params'] = params.get('extra_params_'+vm_name)
+
+    # ksm_size: amount of memory used by allocator
+    ksm_size = mem - guest_reserve
+    logging.info("ksm_size = %dM" % (ksm_size))
+
+    # Creating the first guest
+    kvm_preprocessing.preprocess_vm(test, params, env, vm_name)
+    lvms.append(kvm_utils.env_get_vm(env, vm_name))
+    if not lvms[0]:
+        raise error.TestError("VM object not found in environment")
+    if not lvms[0].is_alive():
+        raise error.TestError("VM seems to be dead; Test requires a living "
+                              "VM")
+
+    logging.info("Booting the first guest %s", lvms[0].name)
+
+    lsessions.append(kvm_utils.wait_for(lvms[0].remote_login, 360, 0, 2))
+    if not lsessions[0]:
+        raise error.TestFail("Could not log into first guest")
+    # Associate vm PID
+    try:
+        tmp = open(params.get('pid_' + vm_name), 'r')
+        params['pid_' + vm_name] = int(tmp.readline())
+    except:
+        raise error.TestFail("Could not get PID of %s" % (vm_name))
+
+    # Creating other guest systems
+    for i in range(1, vmsc):
+        vm_name = "vm" + str(i + 1)
+        params['pid_' + vm_name] = kvm_utils.generate_tmp_file_name(vm_name,
+                                                                    'pid')
+        params['extra_params_' + vm_name] = params.get('extra_params')
+        params['extra_params_' + vm_name] += (" -pidfile %s" %
+                                             (params.get('pid_' + vm_name)))
+        params['extra_params'] = params.get('extra_params_' + vm_name)
+
+        # Last VM is later used to run more allocators simultaneously
+        lvms.append(lvms[0].clone(vm_name, params))
+        kvm_utils.env_register_vm(env, vm_name, lvms[i])
+        params['vms'] += " " + vm_name
+
+        logging.info("Booting guest %s" % lvms[i].name)
+        if not lvms[i].create():
+            raise error.TestFail("Cannot create VM %s" % lvms[i].name)
+        if not lvms[i].is_alive():
+            raise error.TestError("VM %s seems to be dead; Test requires a"
+                                  "living VM" % lvms[i].name)
+
+        lsessions.append(kvm_utils.wait_for(lvms[i].remote_login, 360, 0, 2))
+        if not lsessions[i]:
+            raise error.TestFail("Could not log into guest %s" %
+                                 lvms[i].name)
+        try:
+            tmp = open(params.get('pid_' + vm_name), 'r')
+            params['pid_' + vm_name] = int(tmp.readline())
+        except:
+            raise error.TestFail("Could not get PID of %s" % (vm_name))
+
+    # Let systems take a rest :-)
+    time.sleep(vmsc * 2 * perf_ratio)
+    logging.info(kvm_test_utils.get_memory_info(lvms))
+
+    # Copy allocator.py into guests
+    pwd = os.path.join(os.environ['AUTODIR'],'tests/kvm')
+    vksmd_src = os.path.join(pwd, "scripts/allocator.py")
+    dst_dir = "/tmp"
+    for vm in lvms:
+        if not vm.copy_files_to(vksmd_src, dst_dir):
+            raise error.TestFail("copy_files_to failed %s" % vm.name)
+    logging.info("Phase 0 => passed")
+
+    if params['ksm_test_size'] == "parallel":
+        split_parallel()
+    elif params['ksm_test_size'] == "serial":
+        initialize_guests()
+        separate_first_guest()
+        split_guest()
diff --git a/client/tests/kvm/tests_base.cfg.sample b/client/tests/kvm/tests_base.cfg.sample
index 2d03f1f..c259a3c 100644
--- a/client/tests/kvm/tests_base.cfg.sample
+++ b/client/tests/kvm/tests_base.cfg.sample
@@ -273,6 +273,24 @@  variants:
         type = physical_resources_check
         catch_uuid_cmd = dmidecode | awk -F: '/UUID/ {print $2}'
 
+    - ksm_overcommit:
+        # Don't preprocess any vms as we need to change its params
+        vms = ''
+        image_snapshot = yes
+        kill_vm_gracefully = no
+        type = ksm_overcommit
+        ksm_swap = yes
+        no hugepages
+        # Overcommit of host memmory
+        ksm_overcommit_ratio = 3
+        # Max paralel runs machine
+        ksm_parallel_ratio = 4
+        variants:
+            - ksm_serial
+                ksm_test_size = "serial"
+            - ksm_parallel
+                ksm_test_size = "parallel"
+
 # NICs
 variants:
     - @rtl8139: