Can jiffies freeze?

hejianet hejianet at linux.vnet.ibm.com
Tue Jan 22 04:07:37 EST 2013


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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