Date:	Tue, 22 Jan 2013 13:03:08 +0530
From:	anish singh <anish198519851985@...il.com>
To:	sandeep kumar <coolsandyforyou@...il.com>
Cc:	"kernelnewbies@...nelnewbies.org" <kernelnewbies@...nelnewbies.org>,
	linux-kernel@...r.kernel.org, linux-arm-msm@...r.kernel.org
Subject: Re: Can jiffies freeze?

On Tue, Jan 22, 2013 at 11:21 AM, sandeep kumar
<coolsandyforyou@...il.com> 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
Please post the code here regarding how did you find out it is zero.
> 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?
Is your watchdog enabled?If it is then you will see panic happening
i.e. soft lockup.
>
> Please clarify...
>
>
> --
> With regards,
> Sandeep Kumar Anantapalli,
>
> _______________________________________________
> Kernelnewbies mailing list
> Kernelnewbies@...nelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
>
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