[Bug 566319] New: Timekeeping in kernel-xen Dom0 drifts minutes-per-day; kenel-desktop OK.
http://bugzilla.novell.com/show_bug.cgi?id=566319 http://bugzilla.novell.com/show_bug.cgi?id=566319#c0 Summary: Timekeeping in kernel-xen Dom0 drifts minutes-per-day; kenel-desktop OK. Classification: openSUSE Product: openSUSE 11.2 Version: Final Platform: All OS/Version: openSUSE 11.2 Status: NEW Severity: Major Priority: P5 - None Component: Xen AssignedTo: jdouglas@novell.com ReportedBy: 0.bugs.only.0@gmail.com QAContact: qa@suse.de Found By: --- Blocker: --- User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2b5) Gecko/20091204 SUSE/3.6b5-2.4 Firefox/3.6b5 On a single server, booting to each of the three following kernels, (1) 2.6.31.5-0.1-desktop, x86_64 (2) 2.6.31.5-0.1-xen, x86_64 (3) 2.6.31.7-0.0.0.8.a22d080-xen, x86_64 time services are running, ps ax | grep ntp 22979 ? Ss 0:00 /usr/sbin/ntpd -p /var/run/ntp/ntpd.pid -g -u ntp:ntp -i /var/lib/ntp -c /etc/ntp.conf checking each after ~6 & 24 hours of up-time, ntpq -p -c rv returns low-jitter, low-offset, full-reach results for the non-xen case, (1), remote refid st t when poll reach delay offset jitter ============================================================================== *clock.fmt.he.ne .PPS. 1 u 2 128 377 14.472 6.176 21.235 +otc2.psu.edu 128.4.1.1 2 u 68 128 377 98.808 17.478 33.898 +clock.isc.org 216.200.141.8 2 u 67 128 377 15.491 -4.421 22.236 +clock.sjc.he.ne .CDMA. 1 u 66 128 377 14.973 14.981 23.539 +zorro.sf-bay.or 216.218.254.202 2 u 77 128 377 14.861 -5.981 14.786 +rrcs-64-183-56- .GPS. 1 u 124 128 377 34.705 11.295 36.253 +nist1.aol-ca.tr .ACTS. 1 u 62 128 377 16.302 8.190 24.812 but for Xen Dom0 (not DomU) for (2) &/or (3), @ full-reach, both offset & jitter remain unacceptably high, remote refid st t when poll reach delay offset jitter ============================================================================== +clock.fmt.he.ne .PPS. 1 u 60 64 377 21.185 -1690.8 658.866 +otc2.psu.edu 128.4.1.1 2 u 33 64 377 109.992 -1754.1 659.825 +clock.isc.org 216.200.141.8 2 u 2 64 377 13.304 -1827.8 676.431 *clock.sjc.he.ne .CDMA. 1 u 46 64 377 21.193 -1724.5 655.151 zorro.sf-bay.or 216.218.254.202 2 u 53 64 377 15.396 -1711.7 653.852 +rrcs-64-183-56- .GPS. 1 u 28 64 377 53.359 -1766.9 657.547 +nist1.aol-ca.tr .ACTS. 1 u 37 64 377 22.613 -1742.4 665.713 with jitter this high, the clock/time begin to drift over time. Over a period of days, the Dom0 clock will drift 10's of minutes. Checking ntpq> associations in each case, (1) ind assID status conf reach auth condition last_event cnt =========================================================== 1 34729 9114 yes yes none falsetick reachable 1 2 34730 9414 yes yes none candidat reachable 1 3 34731 9414 yes yes none candidat reachable 1 4 34732 9414 yes yes none candidat reachable 1 5 34733 9314 yes yes none outlyer reachable 1 6 34734 9414 yes yes none candidat reachable 1 7 34735 9614 yes yes none sys.peer reachable 1 (3) ind assID status conf reach auth condition last_event cnt =========================================================== 1 20495 9434 yes yes none candidat reachable 3 2 20496 9434 yes yes none candidat reachable 3 3 20497 9434 yes yes none candidat reachable 3 4 20498 9634 yes yes none sys.peer reachable 3 5 20499 9034 yes yes none reject reachable 3 6 20500 9434 yes yes none candidat reachable 3 7 20501 9434 yes yes none candidat reachable 3 shows all servers reachable, but different conditions. this noisy time drift in Dom0 is reproducible on 4 different machines i've tested, all similarly configured, all with X86_64 procs, but with different Motherboards Reproducible: Always Steps to Reproduce: 1. 2. 3. -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
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Charles Arnold
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song james
http://bugzilla.novell.com/show_bug.cgi?id=566319 http://bugzilla.novell.com/show_bug.cgi?id=566319#c2 --- Comment #2 from mail ignored <0.bugs.only.0@gmail.com> 2009-12-22 06:00:23 UTC --- (In reply to comment #1) ..
It seems little time drift. the kernel I used is: 2.6.31.5-26_8_xtp-xen, seems newer than yours "index 2"
Yes, newer than (2) 2.6.31.5-0.1-xen, x86_64 installed from distro which mirrors http://download.opensuse.org/repositories/openSUSE:/11.2/standard, but not as new as, (3) 2.6.31.7-0.0.0.8.a22d080-xen, x86_64 which was installed from "KOTD" @ http://ftp.suse.com/pub/projects/kernel/kotd/openSUSE-11.2/x86_64/ -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
http://bugzilla.novell.com/show_bug.cgi?id=566319 http://bugzilla.novell.com/show_bug.cgi?id=566319#c3 --- Comment #3 from mail ignored <0.bugs.only.0@gmail.com> 2009-12-22 17:30:38 UTC --- fyi, a test of updating Dom0 to, uname -a Linux t4 2.6.31.9-0.0.0.2.76fed8b-xen #1 SMP 2009-12-19 18:52:11 +0100 x86_64 x86_64 x86_64 GNU/Linux after ~ 8hrs uptime, still reports unacceptably high offset & jitter remote refid st t when poll reach delay offset jitter ============================================================================== +clock.fmt.he.ne .PPS. 1 u 44 64 377 24.661 -1095.1 617.255 +otc2.psu.edu 128.118.2.33 2 u 41 64 377 105.908 -1101.1 622.337 +clock.isc.org 204.123.2.5 2 u 43 64 377 14.948 -1100.1 620.845 +clock.sjc.he.ne .CDMA. 1 u 40 64 377 23.276 -1104.2 622.843 +zorro.sf-bay.or 216.218.254.202 2 u 33 64 377 15.958 -1121.3 632.686 +rrcs-64-183-56- .GPS. 1 u 36 64 377 49.034 -1119.0 624.295 *nist1.aol-ca.tr .ACTS. 1 u 38 64 377 24.509 -1102.4 613.754 with boot to kernel-desktop/default, i.e. non-xen, is, as before, OK. -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
http://bugzilla.novell.com/show_bug.cgi?id=566319 http://bugzilla.novell.com/show_bug.cgi?id=566319#c4 mail ignored <0.bugs.only.0@gmail.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |NEEDINFO Info Provider| |jsong@novell.com --- Comment #4 from mail ignored <0.bugs.only.0@gmail.com> 2009-12-24 17:18:01 UTC --- (In reply to comment #1)
It seems little time drift.
can you provide your @Dom0 output of: rpm -qa | egrep -i "xen-3|ntp|kernel-xen" cat /etc/ntp.conf cat /etc/sysconfig/ntp cat /sys/devices/system/clocksource/clocksource0/current_clocksource cat /proc/sys/xen/independent_wallclock cat /etc/sysctl.conf for comparison/test? thanks. -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
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--- Comment #5 from song james
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song james
http://bugzilla.novell.com/show_bug.cgi?id=566319 http://bugzilla.novell.com/show_bug.cgi?id=566319#c7 mail ignored <0.bugs.only.0@gmail.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |NEEDINFO Info Provider| |jsong@novell.com --- Comment #7 from mail ignored <0.bugs.only.0@gmail.com> 2009-12-25 02:26:50 UTC --- (In reply to comment #6)
information provide
thanks. looking at your info, ntp.conf is mostly the same. i note you've config'd an Undisciplined local clock (http://doc.ntp.org/4.2.4/drivers/driver1.html), cat ntp.conf ... server 127.127.1.0 # local clock (LCL) fudge 127.127.1.0 stratum 10 with 'fudge' @ stratum 10, and you've not set 'prefer' @ server. as a result, your server is sync'd to stratum 11, processor="x86_64", system="Linux/2.6.31.5-26_8_xtp-xen", leap=00, -> stratum=11, precision=-20, rootdelay=0.000, rootdispersion=948.773, peer=13435, refid=LOCAL(0), reftime=cedab95e.a26cbae8 Tue, Dec 22 2009 11:19:58.634, poll=6, clock=cedab987.6f80557e Tue, Dec 22 2009 11:20:39.435, state=4, offset=0.000, frequency=48.901, jitter=0.001, noise=0.001, stability=24.935, tai=0 remote refid st t when poll reach delay offset jitter ============================================================================== -> *LOCAL(0) .LOCL. 10 l 41 64 17 0.000 0.000 0.001 and not to the stratum 2/3 servers you're accessing via *pool* servers. could you either provision/discipline your local clock with LOCKCLOCK, or better yet, remove it, leaving only external, disciplined references? and re-post your results? also, your data above is @ system=Linux/2.6.31.5-26_8_xtp-xen (which I don't have access to), but which version of xen are you running from among xen-3.5.0_20605_01-1.x86_64 xen-3.4.1_19718_03-1_7_xtp.x86_64 xen-3.4.1_19718_05-1_9_xtp.x86_64 xen-3.4.1_19718_02-1.7.x86_64 xen-3.4.1_19718_03-1.x86_64 xen-3.4.1_19718_03-1_20_xtp.x86_64 xen-3.4.1_19718_05-1.x86_64 xen-3.5.0_20303_01-1.x86_64 ? i've, rpm -qa | grep -i xen-3 xen-3.4.1_19718_04-28.1.x86_64 (from http://download.opensuse.org/repositories/Virtualization/openSUSE_11.2) which is not in your collection. i'm not at all certain if xen pkg plays a part in timing, or if that's all/only in kernel-xen ... in any case, this should be behaving; atm, it reproducibly not across multiple boxes. -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
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--- Comment #8 from song james
http://bugzilla.novell.com/show_bug.cgi?id=566319 http://bugzilla.novell.com/show_bug.cgi?id=566319#c9 --- Comment #9 from mail ignored <0.bugs.only.0@gmail.com> 2009-12-25 05:30:06 UTC --- Created an attachment (id=334288) --> (http://bugzilla.novell.com/attachment.cgi?id=334288) requested config info
Could you give your output in comment #4 and your physical hardware list?
as requested; not sure what phys h/w you need. -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
http://bugzilla.novell.com/show_bug.cgi?id=566319 http://bugzilla.novell.com/show_bug.cgi?id=566319#c10 mail ignored <0.bugs.only.0@gmail.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEEDINFO |NEW Info Provider|jsong@novell.com | --- Comment #10 from mail ignored <0.bugs.only.0@gmail.com> 2009-12-25 05:30:58 UTC --- info provided -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
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--- Comment #11 from song james
http://bugzilla.novell.com/show_bug.cgi?id=566319 http://bugzilla.novell.com/show_bug.cgi?id=566319#c12 --- Comment #12 from mail ignored <0.bugs.only.0@gmail.com> 2009-12-28 02:22:14 UTC --- (1) from above, but which version of xen are you running from among xen-3.5.0_20605_01-1.x86_64 xen-3.4.1_19718_03-1_7_xtp.x86_64 xen-3.4.1_19718_05-1_9_xtp.x86_64 xen-3.4.1_19718_02-1.7.x86_64 xen-3.4.1_19718_03-1.x86_64 xen-3.4.1_19718_03-1_20_xtp.x86_64 xen-3.4.1_19718_05-1.x86_64 xen-3.5.0_20303_01-1.x86_64 ? (2) you've demonstrated that your box is different than each of my five. any hints as to what the difference/problem is? it's clearly reproducible here. -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
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--- Comment #13 from song james
(1) from above,
but which version of xen are you running from among
xen-3.5.0_20605_01-1.x86_64 xen-3.4.1_19718_03-1_7_xtp.x86_64 xen-3.4.1_19718_05-1_9_xtp.x86_64 xen-3.4.1_19718_02-1.7.x86_64 xen-3.4.1_19718_03-1.x86_64 xen-3.4.1_19718_03-1_20_xtp.x86_64 xen-3.4.1_19718_05-1.x86_64 xen-3.5.0_20303_01-1.x86_64
My version of xen is xen-3.4.1_19718_05-1.gz.
(2) you've demonstrated that your box is different than each of my five. any hints as to what the difference/problem is? it's clearly reproducible here.
The cpu of my box is "Intel(R) Core(TM)2 Duo CPU E6550 @ 2.33GHz". Moreover, the timer of dom0 I used is RTC, the ICH of mainboard is ICH9. CPU and time source all affect the timekeeping. -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
http://bugzilla.novell.com/show_bug.cgi?id=566319 http://bugzilla.novell.com/show_bug.cgi?id=566319#c14 --- Comment #14 from mail ignored <0.bugs.only.0@gmail.com> 2009-12-28 02:51:13 UTC --- (In reply to comment #13)
The cpu of my box is "Intel(R) Core(TM)2 Duo CPU E6550 @ 2.33GHz".
Do you think it's an AMD-specific problem?
Moreover, the timer of dom0 I used is RTC,
Unclear what you're doing here. I presume an RTC kernel module is involved? What/how are you invoking here? Is it *required* for accurate timekeeping @ Dom0?
the ICH of mainboard is ICH9.
Mine Southbridges are all AMD ... e.g., the box I'm looking at now has an SB700 (http://en.wikipedia.org/wiki/AMD_700_chipset_series#Southbridges).
CPU and time source all affect the timekeeping.
Is there a fix to consider here? -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
http://bugzilla.novell.com/show_bug.cgi?id=566319 http://bugzilla.novell.com/show_bug.cgi?id=566319#c15 --- Comment #15 from mail ignored <0.bugs.only.0@gmail.com> 2009-12-28 02:53:35 UTC --- fyi, @ 1 of the affected boxes cat /proc/driver/rtc rtc_time : 19:52:43 rtc_date : 2009-12-27 alrm_time : 21:40:37 alrm_date : ****-**-22 alarm_IRQ : no alrm_pending : no 24hr : yes periodic_IRQ : no update_IRQ : no HPET_emulated : no DST_enable : no periodic_freq : 1024 batt_status : okay -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
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--- Comment #16 from song james
(In reply to comment #6)
which is not in your collection. i'm not at all certain if xen pkg plays a part in timing, or if that's all/only in kernel-xen ...
-- yes， xen pkg and dom0's kernel all play part in timekeeping of dom0. -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
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--- Comment #17 from song james
http://bugzilla.novell.com/show_bug.cgi?id=566319 http://bugzilla.novell.com/show_bug.cgi?id=566319#c18 --- Comment #18 from mail ignored <0.bugs.only.0@gmail.com> 2009-12-28 16:06:46 UTC --- (In reply to comment #17)
Whether or not the systme time in dom0 is accurate after long time running without ntp involved?
I've turned off ntp service on two of the boxes, and will let them run for awhile as a test ... in any case, with ntp running, even if RTC is inaccurate, xen's supposed to write correct time to it: "... If domain 0 runs ntpdate, ntpd, etc. then the synchronised time will automatically be pushed down to Xen every minute (and written to the RTC every 11 minutes, just as normal x86 Linux does). ..." The problem here is clearly when using ntp with xen/Dom0 ... since with kernel-default -- i.e. no xen -- ntp timekeeping works perfectly. if RTC was, somehow, "the" problem it would also manifest in non-xen, kernel-default, no? -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
http://bugzilla.novell.com/show_bug.cgi?id=566319 http://bugzilla.novell.com/show_bug.cgi?id=566319#c19 --- Comment #19 from mail ignored <0.bugs.only.0@gmail.com> 2009-12-28 19:02:29 UTC --- I turned off ntp(d) service, and took a look at clock behavior @ kernel-xen & kernel-default. Follow the tests below, noting that @kernel-default, all clocks behave as expected and keep correct time across reboots. @kernel-xen, however, -- system boots to incorrect time -- allows set/reset at console -- loses those corrections across reboot to kernel-xen On reboot to kernel-default, everything returns to normal/expected behavior. I.e., there seems to be a problem with timekeeping/setting -- without the presence of NTP -- when using kernel-xen. ACTUAL/VERIFIED TIME: date Mon Dec 28 10:21:49 PST 2009 (boot to kernel-default) service ntp status Checking for network time protocol daemon (NTPD): unused chkconfig ntp off uname -a Linux server 2.6.31.9-0.0.0.2.76fed8b-default #1 SMP 2009-12-19 18:52:11 +0100 x86_64 x86_64 x86_64 GNU/Linux service ntp status Checking for network time protocol daemon (NTPD): unused sntp clock.isc.org && date && hwclock --show 2009 Dec 28 10:24:37.000416 + 3.249517 +/- 0.018179 secs Mon Dec 28 10:24:40 PST 2009 Mon 28 Dec 2009 10:24:41 AM PST -0.436828 seconds ntpd -q sntp clock.isc.org && date && hwclock --show 2009 Dec 28 10:25:42.000836 + 0.002397 +/- 0.020053 secs Mon Dec 28 10:25:42 PST 2009 Mon 28 Dec 2009 10:25:56 AM PST -0.031536 seconds (reboot to kernel-default) uname -a Linux server 2.6.31.9-0.0.0.2.76fed8b-default #1 SMP 2009-12-19 18:52:11 +0100 x86_64 x86_64 x86_64 GNU/Linux sntp clock.isc.org && date && hwclock --show 2009 Dec 28 10:27:56.000677 + 0.264198 +/- 0.016632 secs Mon Dec 28 10:27:56 PST 2009 Mon 28 Dec 2009 10:27:57 AM PST -0.171892 seconds (reboot to kernel-default) -> all times correct (reboot to kernel-default) -> all times correct etc etc (reboot to kernel-xen) uname -a Linux server 2.6.31.9-0.0.0.2.76fed8b-xen #1 SMP 2009-12-19 18:52:11 +0100 x86_64 x86_64 x86_64 GNU/Linux sntp clock.isc.org && date && hwclock --show ! 2009 Dec 28 10:31:32.000206 + 28800.725203 +/- 0.013941 secs ! Mon Dec 28 18:31:32 PST 2009 Mon 28 Dec 2009 10:31:33 AM PST -0.638684 seconds (reboot to kernel-default) uname -a Linux server 2.6.31.9-0.0.0.2.76fed8b-default #1 SMP 2009-12-19 18:52:11 +0100 x86_64 x86_64 x86_64 GNU/Linux sntp clock.isc.org && date && hwclock --show 2009 Dec 28 10:38:49.000867 + 0.250226 +/- 0.023099 secs Mon Dec 28 10:38:50 PST 2009 Mon 28 Dec 2009 10:38:51 AM PST -0.998094 seconds (reboot to kernel-xen) uname -a Linux server 2.6.31.9-0.0.0.2.76fed8b-xen #1 SMP 2009-12-19 18:52:11 +0100 x86_64 x86_64 x86_64 GNU/Linux sntp clock.isc.org && date && hwclock --show 2009 Dec 28 10:44:11.000592 + 28800.871300 +/- 0.022048 secs Mon Dec 28 18:44:12 PST 2009 Mon 28 Dec 2009 10:44:12 AM PST -0.267028 seconds ntpd -q sntp clock.isc.org && date && hwclock --show ! 2009 Dec 28 10:44:34.000303 + 28800.920231 +/- 0.024779 secs ! Mon Dec 28 18:44:35 PST 2009 Mon 28 Dec 2009 10:44:35 AM PST -0.556027 seconds hwclock --localtime hwclock --set --date="12/28/09 10:46:00" hwclock --hctosys sntp clock.isc.org && date && hwclock --show ! 2009 Dec 28 10:45:52.000935 + 9.124311 +/- 0.023619 secs ! Mon Dec 28 10:46:02 PST 2009 Mon 28 Dec 2009 10:46:03 AM PST -0.927803 seconds (reboot to kernel-xen) uname -a Linux server 2.6.31.9-0.0.0.2.76fed8b-xen #1 SMP 2009-12-19 18:52:11 +0100 x86_64 x86_64 x86_64 GNU/Linux sntp clock.isc.org && date && hwclock --show ! 2009 Dec 28 10:49:37.000666 + 28809.558159 +/- 0.015951 secs ! Mon Dec 28 18:49:47 PST 2009 Mon 28 Dec 2009 10:49:47 AM PST -0.193727 seconds (reboot to kernel-default) uname -a Linux server 2.6.31.9-0.0.0.2.76fed8b-default #1 SMP 2009-12-19 18:52:11 +0100 x86_64 x86_64 x86_64 GNU/Linux sntp clock.isc.org && date && hwclock --show 2009 Dec 28 10:55:20.000262 + 9.186972 +/- 0.022872 secs Mon Dec 28 10:55:29 PST 2009 Mon 28 Dec 2009 10:55:30 AM PST -0.608288 seconds -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
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Charles Arnold
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--- Comment #20 from song james
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Lin Ma
http://bugzilla.novell.com/show_bug.cgi?id=566319 http://bugzilla.novell.com/show_bug.cgi?id=566319#c22 --- Comment #22 from mail ignored <0.bugs.only.0@gmail.com> 2010-01-08 16:08:56 UTC --- on your *Intel* platform, what do you see with ntp *disabled*, as in Comment 19 (https://bugzilla.novell.com/show_bug.cgi?id=566319#c19)? specifically, checking the cycle of chkconfig ntp off (reboot to kernel-default) sntp clock.isc.org && date && hwclock --show ntpd -q sntp clock.isc.org && date && hwclock --show (reboot to kernel-xen) sntp clock.isc.org && date && hwclock --show (reboot to kernel-default) sntp clock.isc.org && date && hwclock --show ? will be interested to see what your results are for AMD ... -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
chkconfig ntp off
(reboot to kernel-default) sntp clock.isc.org && date && hwclock --show ntpd -q sntp clock.isc.org && date && hwclock --show
(reboot to kernel-xen) sntp clock.isc.org && date && hwclock --show
(reboot to kernel-default) sntp clock.isc.org && date && hwclock --show
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http://bugzilla.novell.com/show_bug.cgi?id=566319#c23
--- Comment #23 from Lin Ma
http://bugzilla.novell.com/show_bug.cgi?id=566319 http://bugzilla.novell.com/show_bug.cgi?id=566319#c24 --- Comment #24 from mail ignored <0.bugs.only.0@gmail.com> 2010-01-10 07:19:04 UTC --- (In reply to comment #23)
I still couldn't reproduce this bug with AMD platform (Dell 1501:AMD Turion64-X2 TL-50 + ATI Radeon Xpress 1150) .. offset=102.115, frequency=31.989, jitter=51.987, noise=79.580, ..
I'm stumped. I can reproduce this problem all day long on each/all of my boxes -- different mobos, different vendors, different installs. One thing does stand out re: your AMD test here -- you're running a Turion64-X2. I've got AMD Phenoms on all my boxes.
(In reply to comment #22) linux-ggdh:~ # sntp clock.isc.org && date && hwclock --show 2010 Jan 09 23:35:52.000936 - 0.006448 +/- 0.199398 secs Sat Jan 9 23:35:52 EST 2010 Sat Jan 9 23:35:53 2010 -0.382018 seconds
(reboot to kernel-xen) sntp clock.isc.org && date && hwclock --show linux-ggdh:~ # sntp clock.isc.org && date && hwclock --show 2010 Jan 09 23:41:43.000175 + 17999.454809 +/- 0.194981 secs Sun Jan 10 04:41:42 EST 2010 Sat Jan 9 23:41:43 2010 -0.146482 seconds
(reboot to kernel-default) sntp clock.isc.org && date && hwclock --show linux-ggdh:~ # sntp clock.isc.org && date && hwclock --show 2010 Jan 09 23:44:46.000300 + 0.483478 +/- 0.196259 secs Sat Jan 9 23:44:45 EST 2010 Sat Jan 9 23:44:47 2010 -0.987769 seconds
Something's really off here. For you, as in my test, the difference (~18000 secs!) between kernel-xen & kernel-default is evident. I have no clue, other than this is a real, observable, reproducible phenomenon. For servers that are time-critical (e.g., mail etc), the jitter and fluctations cause sometimes fatal errors. -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
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http://bugzilla.novell.com/show_bug.cgi?id=566319#c25
--- Comment #25 from Lin Ma
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--- Comment #26 from Lin Ma
(In reply to comment #24) For servers that are time-critical (e.g., mail etc), the jitter and fluctations cause sometimes fatal errors.
I will be tracing this issue and try to repro it. -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
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--- Comment #27 from Lin Ma
http://bugzilla.novell.com/show_bug.cgi?id=566319 http://bugzilla.novell.com/show_bug.cgi?id=566319#c28 --- Comment #28 from mail ignored <0.bugs.only.0@gmail.com> 2010-01-12 15:30:39 UTC --- (In reply to comment #26)
The bug really cound't be reproduced on my AMD box(8 Processors) I've run the test for 24 hours, the offset and the jitter both have correct values.
:-/ That' re: ntpd. You *are*, however, seeing the "off by ~18000 seconds", e.g.,
(reboot to kernel-xen) sntp clock.isc.org && date && hwclock --show linux-ggdh:~ # sntp clock.isc.org && date && hwclock --show 2010 Jan 09 23:41:43.000175 + 17999.454809 +/- 0.194981 secs Sun Jan 10 04:41:42 EST 2010
only when booted to -xen, without the presence of ntpd ...
I have no idea either.
The ability to reproduce this on multiple boxes, and the fact that timekeeping is just fine when !kernel-xen, still points to something unique to Xen ... &/or the xen kernel itself -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
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--- Comment #29 from Lin Ma
(reboot to kernel-xen) ...... sntp clock.isc.org && date && hwclock --show ! 2009 Dec 28 10:31:32.000206 + 28800.725203 +/- 0.013941 secs ! Mon Dec 28 18:31:32 PST 2009 Mon 28 Dec 2009 10:31:33 AM PST -0.638684 seconds ......
(In reply to comment #23)
(reboot to kernel-xen) ...... sntp clock.isc.org && date && hwclock --show linux-ggdh:~ # sntp clock.isc.org && date && hwclock --show 2010 Jan 09 23:41:43.000175 + 17999.454809 +/- 0.194981 secs Sun Jan 10 04:41:42 EST 2010 Sat Jan 9 23:41:43 2010 -0.146482 seconds ......
Why does the value look like above(~17999 or ~28800 or ...) ? The reason is: Xen kernel uses UTC/GMT time as its standard time. When we unselect "Hardware Clock Set to UTC" during SUSE installation, (*HWCLOCK="--localtime"* will be saved in /etc/sysconfig/clock) xen kernel think it needs to adjust the clock to UTC when it boots up every time. For 2 instances: if timezone we selected is PST(GMT-8) during installation, xen kernel will increase 8 hrs(28800s) for system clock if timezone we selected is EST(GMT-5) during installation, xen kernel will increase 5 hrs(18000s) for system clock When we select "Hardware Clock Set to UTC" during SUSE installation, (*HWCLOCK="-u"* will be saved in /etc/sysconfig/clock) xen kernel will think that the system clock is UTC time already. it doesn't need to adjust the system clock when it boots up every time. So as long as we ensure that *HWCLOCK="-u"* is saved in /etc/sysconfig/clock, Whatever we boot from default-kernel or xen-kernel, we will never see any "inappropriate" values when using "sntp clock.isc.org && date && hwclock --show". -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
http://bugzilla.novell.com/show_bug.cgi?id=566319 http://bugzilla.novell.com/show_bug.cgi?id=566319#c mail ignored <0.bugs.only.0@gmail.com> changed: What |Removed |Added ---------------------------------------------------------------------------- URL| |http://lists.xensource.com/ | |archives/html/xen-users/201 | |0-01/msg00298.html -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
http://bugzilla.novell.com/show_bug.cgi?id=566319 http://bugzilla.novell.com/show_bug.cgi?id=566319#c30 --- Comment #30 from mail ignored <0.bugs.only.0@gmail.com> 2010-01-16 03:52:44 UTC --- upgrading to, rpm -qa | grep -i ^xen xen-devel-4.0.0_20809_01-29.1.x86_64 xen-kmp-default-4.0.0_20809_01_2.6.31.5_0.1-29.1.x86_64 xen-4.0.0_20809_01-29.1.x86_64 xen-libs-4.0.0_20809_01-29.1.x86_64 xen-tools-4.0.0_20809_01-29.1.x86_64 with uname -a Linux server 2.6.31.8-0.1-xen #1 SMP 2009-12-15 23:55:40 +0100 x86_64 x86_64 x86_64 GNU/Linux unfortunately, seems to make little, if any, difference. after 6 hours runtime, ntpq -p -c rv Fri Jan 15 19:49:11 2010 assID=0 status=06f4 leap_none, sync_ntp, 15 events, event_peer/strat_chg, version="ntpd 4.2.4p8@1.1612 Mon Dec 28 17:26:30 UTC 2009 (1)", processor="x86_64", system="Linux/2.6.31.8-0.1-xen", leap=00, stratum=2, precision=-20, rootdelay=16.330, rootdispersion=168.890, peer=34002, refid=207.200.81.113, reftime=cefbb45c.591c7648 Fri, Jan 15 2010 19:43:24.348, poll=6, clock=cefbb5b7.7c7c61db Fri, Jan 15 2010 19:49:11.486, state=2, offset=-92.476, frequency=-500.000, jitter=396.383, noise=32.695, stability=74.213 remote refid st t when poll reach delay offset jitter ============================================================================== +clock.fmt.he.ne .PPS. 1 u 38 64 377 21.120 -610.08 395.815 +otc2.psu.edu 18.26.4.105 2 u 57 64 377 109.544 -569.92 336.500 +clock.isc.org .GPS. 1 u 4 64 377 21.495 -674.04 406.262 +clock.sjc.he.ne .CDMA. 1 u 18 64 377 20.902 -639.52 395.102 +zorro.sf-bay.or 216.218.254.202 2 u 39 64 377 18.867 -602.46 386.990 *nist1.aol-ca.tr .ACTS. 1 u 25 64 377 29.590 -623.97 394.603 -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
http://bugzilla.novell.com/show_bug.cgi?id=566319 http://bugzilla.novell.com/show_bug.cgi?id=566319#c31 --- Comment #31 from mail ignored <0.bugs.only.0@gmail.com> 2010-01-16 20:16:10 UTC --- per discussions on xen ML, in an attempt to determine if the timekeeping problems are kernel- or xen-related, built & booted to a non-opensuse, pvops kernel sourced from xen.git. booting to the hypervisor+non-opensuse kernel results in unacceptably high jitter/offset. booting to the non-opensuse kernel, with no hypervisor, timekeeping is, again, quiet & stable subject to interpretation of the following results, it seems xen, not kernel, related. unless three kernels, from two vendors, are coincidentally all suffering the same timekeeping-related problems. it's not clear whether the problem is opensuse-xen, or upstream-xen ... here are the details: following http://lists.xensource.com/archives/html/xen-devel/2009-12/msg01127.html http://wiki.xensource.com/xenwiki/XenParavirtOps http://wiki.xensource.com/xenwiki/Kernel.org_Linux_on_Xen cd /home/workspace && rm -rf linux-2.6-xen git clone git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen.git linux-2.6-xen cd linux-2.6-xen make clean cp -a .config .config-old wget -O .config http://pasik.reaktio.net/xen/pv_ops-dom0-debug/config-2.6.31.4-pvops_dom0-x8... make oldconfig ... Xen PCI Frontend (XEN_PCIDEV_FRONTEND) [N/m/y/?] (NEW) <-- m ... "IMQ" target support (NETFILTER_XT_TARGET_IMQ) [N/m/?] (NEW) <-- m ... IMQ (intermediate queueing device) support (IMQ) [M/y/?] (NEW) <-- [enter] ... Block-device tap backend driver (XEN_BLKDEV_TAP) [N/m/y/?] (NEW) <-- m ... make bzImage make modules make modules_install strip vmlinux -o vmlinux-stripped gzip vmlinux-stripped -c > vmlinuz-gzipped ls -al .config \ System.map \ arch/x86/boot/bzImage \ vmlinux \ vmlinux-stripped \ vmlinuz-gzipped cp -a .config /boot/config-2.6.31.6 cp -a System.map /boot/System.map-2.6.31.6 cp -a arch/x86/boot/bzImage /boot/vmlinuz-2.6.31.6 mkinitrd ls -al /boot/*2.6.31.6* -rw-r--r-- 1 root root 98510 2010-01-16 03:02 /boot/config-2.6.31.6 -rw-r--r-- 1 root root 21304611 2010-01-16 04:14 /boot/initrd-2.6.31.6 -rw-r--r-- 1 root root 1940879 2010-01-16 03:14 /boot/System.map-2.6.31.6 -rw-r--r-- 1 root root 3751936 2010-01-16 03:14 /boot/vmlinuz-2.6.31.6 vi /boot/grub/menu.lst .. title xen.git root (hd0,0) kernel /xen.gz loglvl=all loglvl_guest=all dom0_mem=1024M vga=gfx-1280x1024x32 console=vga,com1 com1=57600,8n1 module /vmlinuz-2.6.31.6 root=/dev/VG0/ROOT rootfstype=ext4 rootflags=journal_checksum resume=/dev/VG0/SWAP nomodeset selinux=0 SELINUX_INIT=NO vga=0x31a console=tty0 console=xvc0,57600 module /initrd-2.6.31.6 title xen.git DISABLED root (hd0,0) kernel /vmlinuz-2.6.31.6 root=/dev/VG_SVR/LV_SVR_DOM0_ROOT rootfstype=ext4 rootflags=journal_checksum resume=/dev/VG_SVR/LV_SVR_DOM0_SWAP nomodeset showopts splash=silent selinux=0 SELINUX_INIT=NO elevator=cfq vga=0x31a console=tty0 console=ttyS0,57600n8 module /initrd-2.6.31.6 .. boot to "xen.git" uname -a Linux test 2.6.31.6 #1 SMP Sat Jan 16 03:14:19 PST 2010 x86_64 x86_64 x86_64 GNU/Linux lsb_release -a LSB Version: core-2.0-noarch:core-3.2-noarch:core-4.0-noarch:core-2.0-x86_64:core-3.2-x86_64:core-4.0-x86_64:desktop-4.0-amd64:desktop-4.0-noarch:graphics-2.0-amd64:graphics-2.0-noarch:graphics-3.2-amd64:graphics-3.2-noarch:graphics-4.0-amd64:graphics-4.0-noarch Distributor ID: SUSE LINUX Description: openSUSE 11.2 (x86_64) Release: 11.2 Codename: n/a service ntp stop rm /etc/adjtime /var/ rm /var/lib/ntp/drift/ntp.drift cat << EOF > /etc/sysconfig/clock HWCLOCK="--utc" SYSTOHC="yes" TIMEZONE="America/Los_Angeles" DEFAULT_TIMEZONE="US/Pacific" EOF hwclock --systohc --utc service ntp start sntp clock.isc.org && date && hwclock --utc --show 2010 Jan 16 04:37:09.000729 + 1.435060 +/- 0.028944 secs Sat Jan 16 04:37:11 PST 2010 Sat 16 Jan 2010 04:37:11 AM PST -0.345191 seconds .. (wait ~ 6 hours) ... date Sat Jan 16 11:01:42 PST 2010 ntpq -p -c rv assID=0 status=06c4 leap_none, sync_ntp, 12 events, event_peer/strat_chg, version="ntpd 4.2.4p8@1.1612 Mon Dec 28 17:26:30 UTC 2009 (1)", processor="x86_64", system="Linux/2.6.31.6", leap=00, stratum=2, precision=-20, rootdelay=14.718, rootdispersion=135.995, peer=11390, refid=66.220.9.122, reftime=cefc89b2.a36f1342 Sat, Jan 16 2010 10:53:38.638, poll=6, clock=cefc8b82.7e523feb Sat, Jan 16 2010 11:01:22.493, state=2, offset=-115.130, frequency=-500.000, jitter=464.242, noise=29.343, stability=154.680 remote refid st t when poll reach delay offset jitter ============================================================================== *clock.fmt.he.ne .PPS. 1 u 29 64 377 21.438 -811.68 462.837 +otc2.psu.edu 129.6.15.29 2 u 7 64 377 109.399 -850.99 470.522 +clock.isc.org .GPS. 1 u 7 64 377 21.440 -854.82 468.274 +clock.sjc.he.ne .CDMA. 1 u 49 64 377 16.889 -780.55 469.481 +zorro.sf-bay.or 216.218.254.202 2 u 59 64 377 20.366 -762.14 458.947 +nist1.aol-ca.tr .ACTS. 1 u 38 64 377 16.260 -795.87 463.170 boot to "xen.git DISABLED" uname -a Linux test 2.6.31.6 #1 SMP Sat Jan 16 09:14:19 PST 2010 x86_64 x86_64 x86_64 GNU/Linux service ntp stop rm /etc/adjtime /var/ rm /var/lib/ntp/drift/ntp.drift service ntp start .. (wait ~ 10 minutes) ... date Sat Jan 16 11:15:05 PST 2010 ntpq -p -c rv assID=0 status=0664 leap_none, sync_ntp, 6 events, event_peer/strat_chg, version="ntpd 4.2.4p8@1.1612 Mon Dec 28 17:26:30 UTC 2009 (1)", processor="x86_64", system="Linux/2.6.31.6", leap=00, stratum=2, precision=-20, rootdelay=22.750, rootdispersion=975.184, peer=43091, refid=66.220.9.122, reftime=cefc8c7c.35ca466a Sat, Jan 16 2010 11:05:32.210, poll=6, clock=cefc8eb9.25103a1f Sat, Jan 16 2010 11:15:05.144, state=3, offset=27.534, frequency=0.000, jitter=6.740, noise=16.331, stability=0.000 remote refid st t when poll reach delay offset jitter ============================================================================== *clock.fmt.he.ne .PPS. 1 u 4 64 377 18.112 10.541 5.892 +otc2.psu.edu 147.84.59.145 2 u 64 64 377 101.103 12.106 8.621 +clock.isc.org .GPS. 1 u 57 64 377 14.990 4.830 9.622 +clock.sjc.he.ne .CDMA. 1 u 59 64 377 16.503 9.299 9.440 +zorro.sf-bay.or 216.218.254.202 2 u 56 64 377 22.212 6.323 11.031 +nist1.aol-ca.tr .ACTS. 1 u 60 64 377 17.076 14.316 9.260 in summary, kernel OS/distro xen timekeeping ------------------------------------- --------------- ------- ------------ opensuse kernel-default-2.6.31.8-0.1 opensuse 11.2 (n/a) OK opensuse kernel-default-2.6.32-41 opensuse 11.2 (n/a) OK opensuse kernel-xen-2.6.31.8-0.1 opensuse 11.2 3.4.x NOISY/FAIL opensuse kernel-xen-2.6.32-41 opensuse 11.2 3.4.x NOISY/FAIL opensuse kernel-xen-2.6.31.8-0.1 opensuse 11.2 4.0.x NOISY/FAIL opensuse kernel-xen-2.6.32-41 opensuse 11.2 4.0.x NOISY/FAIL xen.git kernel-2.6.31.6 (pvops Dom0) opensuse 11.2 4.0.x NOISY/FAIL xen.git kernel-2.6.31.6 opensuse 11.2 (n/a) OK i.e., 3 different kernel versions, from two different vendors, have low-noise/accurate timekeeping in NON-xen configs. boot any of those kernels with either v34x or v40x hypervisor in place, and timekeeping suffers from unusably excessive jitter & offset. again, all fully reproducible on multiple boxes. -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
http://bugzilla.novell.com/show_bug.cgi?id=566319 http://bugzilla.novell.com/show_bug.cgi?id=566319#c32 --- Comment #32 from mail ignored <0.bugs.only.0@gmail.com> 2010-01-18 22:19:09 UTC --- the issue is real, fully reproducible, and, is, apparently, a result of the default setting of Xen's default Platform Timer == HPET @ boot to default xen settings, xm dmesg | egrep -i "timer|clock" (XEN) ACPI: PM-Timer IO Port: 0x808 (XEN) ..TIMER: vector=0xF0 apic1=0 pin1=2 apic2=-1 pin2=-1 (XEN) Platform timer is 14.284MHz HPET (XEN) HPET: 4 timers in total, 3 timers will be used for broadcast (XEN) mcheck_poll: Machine check polling timer started. results in the above documented noisy ntp behavior. otoh, adding a default-override spec'n of "clocksource=" on the Xen cmd line, NOT the widely used spec'n ('xen' vs 'jiffies') on the kernel line, fixes the problem. afaict, assigning clocksource= on the Xen cmd line is completely undocumented @ either the Xen wiki or in the Xen user's guide. e.g., booting to, /xen.gz ... clocksource=acpi ... then, xm dmesg | grep -i timer (XEN) ACPI: PM-Timer IO Port: 0x808 (XEN) ..TIMER: vector=0xF0 apic1=0 pin1=2 apic2=-1 pin2=-1 (XEN) Platform timer is 3.579MHz ACPI PM Timer (XEN) HPET: 4 timers in total, 3 timers will be used for broadcast (XEN) mcheck_poll: Machine check polling timer started. ~ 15 minutes, quiet/stable operation @ stratum=2, full reach. assID=0 status=0684 leap_none, sync_ntp, 8 events, event_peer/strat_chg, version="ntpd 4.2.4p8@1.1612 Mon Dec 28 17:26:30 UTC 2009 (1)", processor="x86_64", system="Linux/2.6.31.8-0.1-xen", leap=00, stratum=2, precision=-20, rootdelay=13.970, rootdispersion=26.079, peer=33500, refid=216.218.254.202, reftime=ceff1d2c.ddbe13c0 Mon, Jan 18 2010 9:47:24.866, poll=6, clock=ceff1e07.464f2053 Mon, Jan 18 2010 9:51:03.274, state=4, offset=15.245, frequency=24.962, jitter=10.571, noise=17.706, stability=7.306 remote refid st t when poll reach delay offset jitter ============================================================================== -clock.fmt.he.ne .PPS. 1 u 41 64 377 16.047 20.346 10.336 -otc2.psu.edu 130.207.244.240 2 u 39 64 377 100.626 14.538 5.387 +clock.isc.org .GPS. 1 u 54 64 377 15.174 -0.843 10.578 *clock.sjc.he.ne .CDMA. 1 u 26 64 377 13.970 12.255 7.051 zorro.sf-bay.or 216.218.254.202 2 u 31 64 377 16.489 13.730 5.781 +nist1.aol-ca.tr .ACTS. 1 u 15 64 377 14.891 5.947 14.596 booting to, /xen.gz ... clocksource=pit ... xm dmesg | grep -i timer (XEN) ACPI: PM-Timer IO Port: 0x808 (XEN) ..TIMER: vector=0xF0 apic1=0 pin1=2 apic2=-1 pin2=-1 (XEN) Platform timer is 1.193MHz PIT (XEN) mcheck_poll: Machine check polling timer started. ~ 20 minutes, quiet/stable operation @ stratum=2, full reach. assID=0 status=0654 leap_none, sync_ntp, 5 events, event_peer/strat_chg, version="ntpd 4.2.4p8@1.1612 Mon Dec 28 17:26:30 UTC 2009 (1)", processor="x86_64", system="Linux/2.6.31.8-0.1-xen", leap=00, stratum=2, precision=-20, rootdelay=16.981, rootdispersion=31.958, peer=63536, refid=207.200.81.113, reftime=ceff2377.503b4ceb Mon, Jan 18 2010 10:14:15.313, poll=6, clock=ceff240e.fa89c747 Mon, Jan 18 2010 10:16:46.978, state=4, offset=9.641, frequency=4.070, jitter=12.958, noise=6.244, stability=0.834 remote refid st t when poll reach delay offset jitter ============================================================================== +clock.fmt.he.ne .PPS. 1 u 30 64 177 15.250 8.422 9.657 +otc2.psu.edu 147.84.59.145 2 u 33 64 177 99.375 10.359 8.906 +clock.isc.org .GPS. 1 u 25 64 177 13.060 2.679 9.501 +clock.sjc.he.ne .CDMA. 1 u 22 64 177 15.097 10.608 7.866 +zorro.sf-bay.or 216.218.254.202 2 u 27 64 177 15.082 9.639 8.443 *nist1.aol-ca.tr .ACTS. 1 u 23 64 177 16.981 15.780 7.743 wrt usgin clocksource=acpi vs clocksource=pit, reading @ http://the-b.org/Linux_timers, it seems (?) acpi may be, in general, the better options, as pit " ... doesn't gain lost time because it doesn't have lost tick correction code ..." iiuc, that references those timers @kernel -- not clear if it is/isn't relevant to Xen ... whether the noisy performance with clocksource=HPET is considered a bug or not is beyond me. as it's, apparently, the DEFAULT that's installed in/with opensuse 11.2, i'd suggest it is. -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
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Jason Douglas
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Preston Millett
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Chunyan Liu
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Chunyan Liu
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