Can jiffies freeze?

[sandeep kumar]

Hi All
I am seeing this problem at the very early in the start_kernel-->
mm_init--> free_highpages, at that time nothing is up and kernel is running
in single thread.

Thanks
Sandeep


On Tue, Jan 22, 2013 at 1:07 AM, hejianet <hejianet at linux.vnet.ibm.com>wrote:

> how about to check the disable/enable timer interrupt?
> cat /proc/stat before/after 2 seconds?
> On 2013-01-22 13:51, sandeep kumar wrote:
> > Hi all
> > As far as I know jiffie counter is incremented HZ times/second. And it is
> > used to measure the time lapses in the kernel code.
> >
> > I m seeing a case where, actualy time spent in some module using giffies
> is
> > zero, but while seeing UART logs i am seein 2 sec time difference. I dont
> > know how to interpret this. The case which i am seeing, hrtimers are not
> > enabled yet, so only thing i can rely are on jiffies.
> >
> > My question here is,
> > Is it possible that the measured time lapse shown is "0"(jiffie count is
> > same before and after), but actually some time is spent?(say some 2 sec)
> >
> > In another way..can jiffies may freeze for some time?
> >
> > Please clarify...
> >
> >
> >
> >
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>
>
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-- 
With regards,
Sandeep Kumar Anantapalli,
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