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Date: Thu, 10 Apr 2008 20:02:58 +0200
From: "Bart Van Assche" <bart.vanassche@gmail.com>
To: "Jack Harvard" <jack.harvard@googlemail.com>
Subject: Re: gettimeofday() resolution in Linux?
Cc: LKML <linux-kernel@vger.kernel.org>
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On Thu, Apr 10, 2008 at 7:57 PM, Jack Harvard
<jack.harvard@googlemail.com> wrote:
> On Thu, Apr 10, 2008 at 6:41 PM, Bart Van Assche
>  <bart.vanassche@gmail.com> wrote:
>  > On Thu, Apr 10, 2008 at 5:59 PM, Jack Harvard
>  > <jack.harvard@googlemail.com> wrote:
>  >
>  > >  Here is an example of gettimeofday results, the time rolls back sometimes.
>  >
>  >  If the result of gettimeofday() rolls back, and there is no process on
>  >  your system that sets the time (like ntpd or hwclock --hctosys) then
>  >  this is a kernel bug. Which kernel version are you using, and which
>  >  kernel patches have been applied to that kernel ?
>
>  It's an embedded system with an ARM processor, uname -a give the following info:
>  Linux (none) 2.6.21-arm1-t2_1 #20 Thu Apr 10 15:20:46 BST 2008 armv6l unknown

Where did the kernel sources come from -- from kernel.org or from an
company that modified the kernel ? Most companies that offer support
for Linux on embedded devices modify the kernel with e.g. hard
real-time support and high resolution timers. It is easy to introduce
bugs by doing so.

Bart.