Continual reading from the PowerPc time base register is not stable

[Csdncannon]

         In my program, the value of the 64-bit time base register is read
out, and you will find the later value is even smaller than the earlier
value from the log “log_timebase”. While the kernel depends on the accuracy
of the timebase for the compensation of the lost PIT interrupt, the negative
value between two continual timebase reading will bring to the jump of the
jiffies. And this timebase problem will bring to the instability of the
gettimeofday system call.

         Do you have any idea about this problem, thanks for your any
advice. Attached is the code and log.


Thanks

Gino
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.ozlabs.org/pipermail/linuxppc-dev/attachments/20100325/9ba21bd2/attachment-0001.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: gettime.c
Type: application/octet-stream
Size: 766 bytes
Desc: not available
URL: <http://lists.ozlabs.org/pipermail/linuxppc-dev/attachments/20100325/9ba21bd2/attachment-0002.obj>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: log_timebase
Type: application/octet-stream
Size: 51492 bytes
Desc: not available
URL: <http://lists.ozlabs.org/pipermail/linuxppc-dev/attachments/20100325/9ba21bd2/attachment-0003.obj>