Re: [KVM-AUTOTEST][PATCH] timedrift support

Yaniv Kaul <ykaul@xxxxxxxxxx> · Mon, 11 May 2009 14:05:01 +0300

On 5/11/2009 1:40 PM, Bear Yang wrote:
Hello.
I have modified my script according Marcelo's suggestion. and resubmit 
my script to you all. :)

Marcelo, Seems except you, no one care my script. I  still want to say 
any suggestion  on my script would be greatly appreciated.

Thanks.

Bear

Marcelo Tosatti wrote:
Bear,

Some comments below.

On Wed, May 06, 2009 at 12:02:21PM +0800, Bear Yang wrote:
Hello everyone,

I like to submit patch to add a new function for 'time drift check' 
for  guest running on KVM.

The TimeDrift design logic is below:
1. Set the host as the NTP server
2. Guest only sync it's clock with host *once* when it booted up.
* if the offset value of ntpdate large than 1 sec, the guest will 
sync  the clock with host.
* if the offset value of ntpdate less than 1 sec, the guest doesn't 
need  sync it's clock with host.
I don't see the value of doing all the NTP stuff above. It poses another 
requirement on the host.

3. Then the cpu stress testing will running on guest.
* a C program will give the real load to guest cpu
Isn't there any available program that can perform a load on the guest 
CPU? Moreover, I believe we want different kinds of loads to be tested 
(mixed with I/O, for example).
4.when the cpustress testing finished. running the commandline 
<ntpdate  -q host-ip> totally 20 times on guest to query the time 
from host and  judge whether the guest clock has drift or not.

The details of my patch is attached.

thanks.

Bear.

I might be missing something, but generally, what I feel should be the 
test is:
1. Load the guest (AND the host - configurable!)
2. Run a program for X minutes on the guest - as measured by the guest 
(say 3 minutes).
3. When it exits, check that indeed Xhost = Xguest (in some cases we've 
seen here: 3:15 on the host, vs. 3:00 on the guest).

Looks like a much simpler plan than yours. And should also be pretty 
portable to Windows.

Y.

diff -urN kvm_runtest_2.bak/cpu_stress.c kvm_runtest_2/cpu_stress.c

--- kvm_runtest_2.bak/cpu_stress.c    1969-12-31 19:00:00.000000000 
-0500
+++ kvm_runtest_2/cpu_stress.c    2009-05-05 22:35:34.000000000 -0400
@@ -0,0 +1,61 @@
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <pthread.h>
+#include <sched.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <math.h>
+#include <unistd.h>
+
+#define MAX_CPUS 256
+#define BUFFSIZE 1024
+
+
+void worker_child(int cpu)
+{
+    int cur_freq;
+    int min_freq;
+    int max_freq;
+    int last_freq;
+    cpu_set_t mask;
+    int i;
+    double x;
+        int d = 0;
+    /*
+     * bind this thread to the specified cpu +     */
+    CPU_ZERO(&mask);
+    CPU_SET(cpu, &mask);
+    sched_setaffinity(0, CPU_SETSIZE, &mask);
+
+    while (d++ != 500000) {
+            for (i=0; i<100000; i++)
+                x = sqrt(x);
+    }
+
+    _exit(0);
+
+}
+
+
+main() {
+    cpu_set_t mask;
+    int i;
+    int code;
+
+    if (sched_getaffinity(0, CPU_SETSIZE, &mask) < 0){
+        perror ("sched_getaffinity");
+        exit(1);
+    }
+
+    for (i=0; i<CPU_SETSIZE; i++)
+        if (CPU_ISSET(i, &mask)){
+            printf ("CPU%d\n",i);
+            if (fork() == 0)
+                worker_child(i);
+        }
+
+
+    wait(&code);
+    exit (WEXITSTATUS(code));
+}
diff -urN kvm_runtest_2.bak/kvm_runtest_2.py 
kvm_runtest_2/kvm_runtest_2.py
--- kvm_runtest_2.bak/kvm_runtest_2.py    2009-04-29 
06:17:29.000000000 -0400
+++ kvm_runtest_2/kvm_runtest_2.py    2009-04-29 08:06:32.000000000 
-0400
@@ -36,6 +36,8 @@
                 "autotest":     test_routine("kvm_tests",           
"run_autotest"),
                 "kvm_install":  test_routine("kvm_install",         
"run_kvm_install"),
                 "linux_s3":     test_routine("kvm_tests",           
"run_linux_s3"),
+                "ntp_server_setup": test_routine("kvm_tests",       
"run_ntp_server_setup"),
+                "timedrift":    test_routine("kvm_tests",           
"run_timedrift"),
                 }

         # Make it possible to import modules from the test's bindir
diff -urN kvm_runtest_2.bak/kvm_tests.cfg.sample 
kvm_runtest_2/kvm_tests.cfg.sample
--- kvm_runtest_2.bak/kvm_tests.cfg.sample    2009-04-29 
06:17:29.000000000 -0400
+++ kvm_runtest_2/kvm_tests.cfg.sample    2009-04-29 
08:09:36.000000000 -0400
@@ -81,6 +81,10 @@
     - linux_s3:      install setup
         type = linux_s3

+    - ntp_server_setup:
+        type = ntp_server_setup
+    - timedrift:      ntp_server_setup
+        type = timedrift
 # NICs
 variants:
     - @rtl8139:
diff -urN kvm_runtest_2.bak/kvm_tests.py kvm_runtest_2/kvm_tests.py
--- kvm_runtest_2.bak/kvm_tests.py    2009-04-29 06:17:29.000000000 
-0400
+++ kvm_runtest_2/kvm_tests.py    2009-05-05 23:45:57.000000000 -0400
@@ -394,3 +394,235 @@
     kvm_log.info("VM resumed after S3")

     session.close()
+
+def run_ntp_server_setup(test, params, env):
+    +    """NTP server configuration and related network file 
modification
+    """
+    kvm_log.debug("run ntp server setup")
+    status = 1
+    # stop firewall for NTP server if it is running.
+    status = os.system("/etc/init.d/iptables status")
+    if status == 0:
+        os.system("/etc/init.d/iptables stop")
+        status = 1
+
+    # prevent dhcp client modify the ntp.conf
+    kvm_log.info("prevent dhcp client modify the ntp.conf")
+
+    config_file = "/etc/sysconfig/network"
+    network_file = open("/etc/sysconfig/network", "a")
+    string = "PEERNTP=no"
+
+    if os.system("grep %s %s" % (string, config_file)):
+        network_file.writelines(str(string)+'\n')
+    +    network_file.close()
+  +    # start ntp server on host
+    kvm_log.info("backup ntp config file")
+
+    ntp_filename = os.path.expanduser("/etc/ntp.conf")
+    # backup ntp config file
+    backup_bootloader_filename = ntp_filename + "_backup"
+    if os.path.exists(ntp_filename):
+        os.rename(ntp_filename, backup_bootloader_filename)
+    +    status = os.system("/etc/init.d/ntpd status")
+    if status == 0:
+        os.system("/etc/init.d/ntpd stop")
+        status = 1    +
+    kvm_log.info("start ntp server on host")
+
+    ntp_cmd = '''
+        echo "restrict default kod nomodify notrap nopeer noquery" 
>> /etc/ntp.conf;\
+        echo "restrict 127.0.0.1" >> /etc/ntp.conf;\
+        echo "driftfile /var/lib/ntp/drift" >> /etc/ntp.conf;\
+        echo "keys /etc/ntp/keys" >> /etc/ntp.conf;\
+        echo "server 127.127.1.0" >> /etc/ntp.conf;\
+        echo "fudge 127.127.1.0 stratum 1" >> /etc/ntp.conf;\
+        service ntpd start;
+        '''

I think it would be better to copy /etc/ntp.conf to a temporary file,
modify that, and start ntpd with the -c option.

After the test is finished, restart ntpd with the default config (if it
was running) via service ntpd restart.

Also I don't see whether your script reports the content of

/sys/devices/system/clocksource/clocksource0/current_clocksource

On the guest? Its important that information is displayed on the test
report.

Looks fine to me other than that, but the kvm-autotest guys probably
have more comments.

Thanks
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