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.
>
> 3. Then the cpu stress testing will running on guest.
> * a C program will give the real load to guest cpu
> 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.
> 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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