stock 2.4.20: loading amd76x_pm makes time jiggle on A7M266-D

From: Kay Diederichs (kay.diederichs@uni-konstanz.de)
Date: Wed Dec 04 2002 - 07:29:55 EST


the subject says it all:

if I use the powersaving module amd76x_pm then the time is not kept. The
hardware is Asus A7M266-D with 2 MP1900 processors, BIOS is 1004 (but I
tried later BIOS versions as well).

Symptoms are:

- ping times vary and there are 'time of day goes back' messages:

64 bytes from xx (1.2.3.4): icmp_seq=4 ttl=64 time=19.549 msec
64 bytes from xx (1.2.3.4): icmp_seq=5 ttl=64 time=2.684 sec
Warning: time of day goes back, taking countermeasures.
64 bytes from xx (1.2.3.4): icmp_seq=6 ttl=64 time=9.799 msec
64 bytes from xx (1.2.3.4): icmp_seq=7 ttl=64 time=88 usec
64 bytes from xx (1.2.3.4): icmp_seq=8 ttl=64 time=20.011 msec
(addresses edited)

- ntpq -p shows a very high jitter:
     remote refid st t when poll reach delay offset
jitter
==============================================================================
 loop8.biologie. 134.34.3.18 2 u 6 64 77 0.807 -1920.6
1804.31
 helix1.biologie 134.34.3.18 2 u 13 64 77 0.348 -1914.9
1803.99

- ntpd complains:

Dec 3 19:18:51 turn22 ntpd[730]: synchronisation lost
Dec 3 20:12:15 turn22 ntpd[730]: synchronisation lost
Dec 3 22:50:40 turn22 ntpd[730]: synchronisation lost
Dec 3 23:01:18 turn22 ntpd[730]: synchronisation lost

- the program 'check_time' (attached) which was once posted by R.
Johnson on this list shows that the internal timekeeping is
inconsistent:

Time = 3dedf443
Last = 3dedf440
Time = 3dedf440
Last = 3dedf443
Time = 3dedf443
Last = 3dedf440
Time = 3dedf440
Last = 3dedf443
Time = 3dedf443
Last = 3dedf440
Time = 3dedf440
Last = 3dedf443
Time = 3dedf443
Last = 3dedf440
Time = 3dedf440

Any ideas? Am I really the only one who has seen these problems (on 4
identical machines, BTW)?

Kay

-- 
Kay Diederichs         http://strucbio.biologie.uni-konstanz.de/~kay 
email: Kay.Diederichs@uni-konstanz.de  Tel +49 7531 88 4049 Fax 3183
When replying to my email, please remove the blanks before and after the
"@" !
Fakultaet fuer Biologie, Universitaet Konstanz, Box M656, D-78457
Konstanz

#include <stdio.h> #include <time.h>

int main() { time_t tim; time_t last; (void)time(&last); (void)time(&tim); for(;;) { (void)time(&tim); if(tim != last) { if((last +1) != tim) { fprintf(stderr,"Time = %08lx\n", tim); fprintf(stderr,"Last = %08lx\n", last); } last = tim; } } }

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