Attachment 159325 Details for Bug 248368 – time drift measurements with ntpd off, varying HT enabled versus disabled.

time drift measurements with ntpd off, varying HT enabled versus disabled.

kernel-time.txt (text/plain), 13.46 KB, created by James Robinson on 2007-07-16 14:34:49 UTC

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Creator: James Robinson

Created: 2007-07-16 14:34:49 UTC

Size: 13.46 KB

patch

obsolete

>Here's how fast it looses time -- about 1.5 seconds per each ~10 seconds. Start out with HT on, ntpd off, then
>use ntpdate in debug mode to show time drift relative to our ntp master. Then, lower in the file, run same experiment
>with HT disabled in the bios. Kernel accounts for time pretty much just fine -- or at least well within tolerance
>for ntpd to keep it in sync.
>
>--------------------
>
>HT ON
>
>[root@build-db02 ~]# uname -a
>Linux build-db02.socialserve.com 2.6.20-1.2962.fc6 #1 SMP Tue Jun 19 18:24:12 EDT 2007 i686 i686 i386 GNU/Linux
>[root@build-db02 ~]# sleep 10; ntpdate -d router
>16 Jul 10:02:20 ntpdate[2274]: ntpdate 4.2.4p2@1.1495-o Thu Jun 21 12:57:42 UTC 2007 (1)
>Looking for host router and service ntp
>host found : router.socialserve.com
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>server 10.1.1.254, port 123
>stratum 3, precision -20, leap 00, trust 000
>refid [10.1.1.254], delay 0.02577, dispersion 0.00002
>transmitted 4, in filter 4
>reference time:    ca45f319.13d6bfea  Mon, Jul 16 2007  9:37:29.077
>originate timestamp: ca45f8ee.93365469  Mon, Jul 16 2007 10:02:22.575
>transmit timestamp:  ca45f8ec.3968a505  Mon, Jul 16 2007 10:02:20.224
>filter delay:  0.02579  0.02579  0.02577  0.02579 
>         0.00000  0.00000  0.00000  0.00000 
>filter offset: 2.350658 2.350649 2.350686 2.350683
>         0.000000 0.000000 0.000000 0.000000
>delay 0.02577, dispersion 0.00002
>offset 2.350686
>
>16 Jul 10:02:20 ntpdate[2274]: step time server 10.1.1.254 offset 2.350686 sec
>[root@build-db02 ~]# sleep 10; ntpdate -d router
>16 Jul 10:02:36 ntpdate[2278]: ntpdate 4.2.4p2@1.1495-o Thu Jun 21 12:57:42 UTC 2007 (1)
>Looking for host router and service ntp
>host found : router.socialserve.com
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>server 10.1.1.254, port 123
>stratum 3, precision -20, leap 00, trust 000
>refid [10.1.1.254], delay 0.02577, dispersion 0.00002
>transmitted 4, in filter 4
>reference time:    ca45f319.13d6bfea  Mon, Jul 16 2007  9:37:29.077
>originate timestamp: ca45f900.b165d15c  Mon, Jul 16 2007 10:02:40.692
>transmit timestamp:  ca45f8fc.bfcd141a  Mon, Jul 16 2007 10:02:36.749
>filter delay:  0.02580  0.02577  0.02579  0.02577 
>         0.00000  0.00000  0.00000  0.00000 
>filter offset: 3.943578 3.943591 3.943602 3.943637
>         0.000000 0.000000 0.000000 0.000000
>delay 0.02577, dispersion 0.00002
>offset 3.943591
>
>16 Jul 10:02:36 ntpdate[2278]: step time server 10.1.1.254 offset 3.943591 sec
>[root@build-db02 ~]# sleep 10; ntpdate -d router
>16 Jul 10:02:47 ntpdate[2282]: ntpdate 4.2.4p2@1.1495-o Thu Jun 21 12:57:42 UTC 2007 (1)
>Looking for host router and service ntp
>host found : router.socialserve.com
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>server 10.1.1.254, port 123
>stratum 3, precision -20, leap 00, trust 000
>refid [10.1.1.254], delay 0.02577, dispersion 0.00002
>transmitted 4, in filter 4
>reference time:    ca45f319.13d6bfea  Mon, Jul 16 2007  9:37:29.077
>originate timestamp: ca45f90c.e37e5862  Mon, Jul 16 2007 10:02:52.888
>transmit timestamp:  ca45f907.df66a550  Mon, Jul 16 2007 10:02:47.872
>filter delay:  0.02583  0.02577  0.02579  0.02577 
>         0.00000  0.00000  0.00000  0.00000 
>filter offset: 5.015806 5.015842 5.015851 5.015885
>         0.000000 0.000000 0.000000 0.000000
>delay 0.02577, dispersion 0.00002
>offset 5.015842
>
>16 Jul 10:02:47 ntpdate[2282]: step time server 10.1.1.254 offset 5.015842 sec
>[root@build-db02 ~]# sleep 10; ntpdate -d router
>16 Jul 10:02:58 ntpdate[2286]: ntpdate 4.2.4p2@1.1495-o Thu Jun 21 12:57:42 UTC 2007 (1)
>Looking for host router and service ntp
>host found : router.socialserve.com
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>server 10.1.1.254, port 123
>stratum 3, precision -20, leap 00, trust 000
>refid [10.1.1.254], delay 0.02577, dispersion 0.00000
>transmitted 4, in filter 4
>reference time:    ca45f319.13d6bfea  Mon, Jul 16 2007  9:37:29.077
>originate timestamp: ca45f919.21ef4eee  Mon, Jul 16 2007 10:03:05.132
>transmit timestamp:  ca45f913.0a42aed1  Mon, Jul 16 2007 10:02:59.040
>filter delay:  0.02583  0.02579  0.02577  0.02577 
>         0.00000  0.00000  0.00000  0.00000 
>filter offset: 6.092300 6.092321 6.092346 6.092375
>         0.000000 0.000000 0.000000 0.000000
>delay 0.02577, dispersion 0.00000
>offset 6.092346
>
>16 Jul 10:02:59 ntpdate[2286]: step time server 10.1.1.254 offset 6.092346 sec
>[root@build-db02 ~]# sleep 10; ntpdate -d router
>16 Jul 10:03:10 ntpdate[2290]: ntpdate 4.2.4p2@1.1495-o Thu Jun 21 12:57:42 UTC 2007 (1)
>Looking for host router and service ntp
>host found : router.socialserve.com
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>server 10.1.1.254, port 123
>stratum 3, precision -20, leap 00, trust 000
>refid [10.1.1.254], delay 0.02577, dispersion 0.00000
>transmitted 4, in filter 4
>reference time:    ca45f319.13d6bfea  Mon, Jul 16 2007  9:37:29.077
>originate timestamp: ca45f925.65d0b428  Mon, Jul 16 2007 10:03:17.397
>transmit timestamp:  ca45f91e.3a145953  Mon, Jul 16 2007 10:03:10.226
>filter delay:  0.02585  0.02577  0.02579  0.02599 
>         0.00000  0.00000  0.00000  0.00000 
>filter offset: 7.170646 7.170690 7.170702 7.170620
>         0.000000 0.000000 0.000000 0.000000
>delay 0.02577, dispersion 0.00000
>offset 7.170690
>
>16 Jul 10:03:10 ntpdate[2290]: step time server 10.1.1.254 offset 7.170690 sec
>[root@build-db02 ~]# sleep 10; ntpdate -d router
>16 Jul 10:03:23 ntpdate[2294]: ntpdate 4.2.4p2@1.1495-o Thu Jun 21 12:57:42 UTC 2007 (1)
>Looking for host router and service ntp
>host found : router.socialserve.com
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>server 10.1.1.254, port 123
>stratum 3, precision -20, leap 00, trust 000
>refid [10.1.1.254], delay 0.02576, dispersion 0.00003
>transmitted 4, in filter 4
>reference time:    ca45f319.13d6bfea  Mon, Jul 16 2007  9:37:29.077
>originate timestamp: ca45f933.aafd3173  Mon, Jul 16 2007 10:03:31.667
>transmit timestamp:  ca45f92b.3e113404  Mon, Jul 16 2007 10:03:23.242
>filter delay:  0.02596  0.02576  0.02580  0.02576 
>         0.00000  0.00000  0.00000  0.00000 
>filter offset: 8.425224 8.425339 8.425350 8.425384
>         0.000000 0.000000 0.000000 0.000000
>delay 0.02576, dispersion 0.00003
>offset 8.425339
>
>16 Jul 10:03:23 ntpdate[2294]: step time server 10.1.1.254 offset 8.425339 sec
>[root@build-db02 ~]# sleep 10; ntpdate -d router
>16 Jul 10:03:34 ntpdate[2298]: ntpdate 4.2.4p2@1.1495-o Thu Jun 21 12:57:42 UTC 2007 (1)
>Looking for host router and service ntp
>host found : router.socialserve.com
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>server 10.1.1.254, port 123
>stratum 3, precision -20, leap 00, trust 000
>refid [10.1.1.254], delay 0.02577, dispersion 0.00002
>transmitted 4, in filter 4
>reference time:    ca45f319.13d6bfea  Mon, Jul 16 2007  9:37:29.077
>originate timestamp: ca45f93f.b6003310  Mon, Jul 16 2007 10:03:43.710
>transmit timestamp:  ca45f936.3a04af92  Mon, Jul 16 2007 10:03:34.226
>filter delay:  0.02579  0.02577  0.02579  0.02577 
>         0.00000  0.00000  0.00000  0.00000 
>filter offset: 9.484152 9.484158 9.484168 9.484199
>         0.000000 0.000000 0.000000 0.000000
>delay 0.02577, dispersion 0.00002
>offset 9.484158
>
>16 Jul 10:03:34 ntpdate[2298]: step time server 10.1.1.254 offset 9.484158 sec
>[root@build-db02 ~]# sleep 10; ntpdate -d router
>16 Jul 10:03:49 ntpdate[2303]: ntpdate 4.2.4p2@1.1495-o Thu Jun 21 12:57:42 UTC 2007 (1)
>Looking for host router and service ntp
>host found : router.socialserve.com
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>server 10.1.1.254, port 123
>stratum 3, precision -20, leap 00, trust 000
>refid [10.1.1.254], delay 0.02577, dispersion 0.00002
>transmitted 4, in filter 4
>reference time:    ca45f319.13d6bfea  Mon, Jul 16 2007  9:37:29.077
>originate timestamp: ca45f950.3ab2eb48  Mon, Jul 16 2007 10:04:00.229
>transmit timestamp:  ca45f945.4aecbfb1  Mon, Jul 16 2007 10:03:49.292
>filter delay:  0.02596  0.02577  0.02579  0.02577 
>         0.00000  0.00000  0.00000  0.00000 
>filter offset: 10.93635 10.93646 10.93647 10.93651
>         0.000000 0.000000 0.000000 0.000000
>delay 0.02577, dispersion 0.00002
>offset 10.936463
>
>16 Jul 10:03:49 ntpdate[2303]: step time server 10.1.1.254 offset 10.936463 sec
>[root@build-db02 ~]# 
>
>
>----------------
>
>HT Off, ntpd off:
>
>[root@build-db02 ~]# uname -a
>Linux build-db02.socialserve.com 2.6.20-1.2962.fc6 #1 SMP Tue Jun 19 18:24:12 EDT 2007 i686 i686 i386 GNU/Linux
>[root@build-db02 ~]# sleep 10; ntpdate -d router
>16 Jul 09:51:52 ntpdate[2250]: ntpdate 4.2.4p2@1.1495-o Thu Jun 21 12:57:42 UTC 2007 (1)
>Looking for host router and service ntp
>host found : router.socialserve.com
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>server 10.1.1.254, port 123
>stratum 3, precision -20, leap 00, trust 000
>refid [10.1.1.254], delay 0.02579, dispersion 0.00000
>transmitted 4, in filter 4
>reference time:    ca45f319.13d6bfea  Mon, Jul 16 2007  9:37:29.077
>originate timestamp: ca45f678.48018d20  Mon, Jul 16 2007  9:51:52.281
>transmit timestamp:  ca45f678.41b06812  Mon, Jul 16 2007  9:51:52.256
>filter delay:  0.02591  0.02580  0.02579  0.02580 
>         0.00000  0.00000  0.00000  0.00000 
>filter offset: 0.024508 0.024548 0.024555 0.024547
>         0.000000 0.000000 0.000000 0.000000
>delay 0.02579, dispersion 0.00000
>offset 0.024555
>
>16 Jul 09:51:52 ntpdate[2250]: adjust time server 10.1.1.254 offset 0.024555 sec
>[root@build-db02 ~]# sleep 10; ntpdate -d router
>16 Jul 09:52:40 ntpdate[2287]: ntpdate 4.2.4p2@1.1495-o Thu Jun 21 12:57:42 UTC 2007 (1)
>Looking for host router and service ntp
>host found : router.socialserve.com
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>server 10.1.1.254, port 123
>stratum 3, precision -20, leap 00, trust 000
>refid [10.1.1.254], delay 0.02580, dispersion 0.00000
>transmitted 4, in filter 4
>reference time:    ca45f319.13d6bfea  Mon, Jul 16 2007  9:37:29.077
>originate timestamp: ca45f6a8.28a8cb41  Mon, Jul 16 2007  9:52:40.158
>transmit timestamp:  ca45f6a8.27f67f4d  Mon, Jul 16 2007  9:52:40.156
>filter delay:  0.02591  0.02582  0.02580  0.02582 
>         0.00000  0.00000  0.00000  0.00000 
>filter offset: 0.002560 0.002595 0.002600 0.002595
>         0.000000 0.000000 0.000000 0.000000
>delay 0.02580, dispersion 0.00000
>offset 0.002600
>
>16 Jul 09:52:40 ntpdate[2287]: adjust time server 10.1.1.254 offset 0.002600 sec
>[root@build-db02 ~]# sleep 10; ntpdate -d router
>16 Jul 09:52:57 ntpdate[2291]: ntpdate 4.2.4p2@1.1495-o Thu Jun 21 12:57:42 UTC 2007 (1)
>Looking for host router and service ntp
>host found : router.socialserve.com
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>server 10.1.1.254, port 123
>stratum 3, precision -20, leap 00, trust 000
>refid [10.1.1.254], delay 0.02580, dispersion 0.00000
>transmitted 4, in filter 4
>reference time:    ca45f319.13d6bfea  Mon, Jul 16 2007  9:37:29.077
>originate timestamp: ca45f6b9.b94b1575  Mon, Jul 16 2007  9:52:57.723
>transmit timestamp:  ca45f6b9.baa71583  Mon, Jul 16 2007  9:52:57.729
>filter delay:  0.02580  0.02582  0.02580  0.02582 
>         0.00000  0.00000  0.00000  0.00000 
>filter offset: -0.00540 -0.00543 -0.00543 -0.00543
>         0.000000 0.000000 0.000000 0.000000
>delay 0.02580, dispersion 0.00000
>offset -0.005409
>
>16 Jul 09:52:57 ntpdate[2291]: adjust time server 10.1.1.254 offset -0.005409 sec
>[root@build-db02 ~]# sleep 10; ntpdate -d router
>16 Jul 09:53:14 ntpdate[2295]: ntpdate 4.2.4p2@1.1495-o Thu Jun 21 12:57:42 UTC 2007 (1)
>Looking for host router and service ntp
>host found : router.socialserve.com
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>receive(10.1.1.254)
>transmit(10.1.1.254)
>server 10.1.1.254, port 123
>stratum 3, precision -20, leap 00, trust 000
>refid [10.1.1.254], delay 0.02576, dispersion 0.00002
>transmitted 4, in filter 4
>reference time:    ca45f319.13d6bfea  Mon, Jul 16 2007  9:37:29.077
>originate timestamp: ca45f6ca.f8c2f059  Mon, Jul 16 2007  9:53:14.971
>transmit timestamp:  ca45f6ca.fc22ff08  Mon, Jul 16 2007  9:53:14.984
>filter delay:  0.02576  0.02582  0.02582  0.02582 
>         0.00000  0.00000  0.00000  0.00000 
>filter offset: -0.01326 -0.01331 -0.01331 -0.01330
>         0.000000 0.000000 0.000000 0.000000
>delay 0.02576, dispersion 0.00002
>offset -0.013264
>
>16 Jul 09:53:14 ntpdate[2295]: adjust time server 10.1.1.254 offset -0.013264 sec
>[root@build-db02 ~]# 
>

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Attachments on bug 248368: 159325