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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-users] ntpd under Xen Dom0 exhibits extremely high jitter/noise? runs stable/quiet under non-xen kernel.
Keir and others, Please check the table in the end of the mail below.. is there hypervisor (boot time) option to make it behave better for ntpd? -- Pasi On Sat, Jan 16, 2010 at 11:17:36AM -0800, mail ignored wrote: > On Thu, Jan 14, 2010 at 8:20 PM, Fajar A. Nugraha <fajar@xxxxxxxxx> wrote: > >> @ novell say it's xen & ntp > >> @ ntp say it's novell & xen > >> @ xen say it's novell & ntp > >> > > > That's why I suggested you use a workaround: use 2.6.18 kernel, either > > from RHEL or from xen.org :D > > If this works -> novell problem > > If this doesn't work -> xen problem > > On Sat, Jan 16, 2010 at 5:05 AM, Fajar A. Nugraha <fajar@xxxxxxxxx> wrote: > > You might want to try latest pv_ops as well > > (http://wiki.xensource.com/xenwiki/XenParavirtOps), which should be > > easier to work with Opensuse since the version number is close. > > it seems it's _not_ the kernel -- unless there's a coincident kernel > problem across source/vendor ... > > per > 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-x86_64 > 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@xxxxxx 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@xxxxxx 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. > > _______________________________________________ > Xen-users mailing list > Xen-users@xxxxxxxxxxxxxxxxxxx > http://lists.xensource.com/xen-users _______________________________________________ Xen-users mailing list Xen-users@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-users
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