From mboxrd@z Thu Jan 1 00:00:00 1970 From: jbarnes@sgi.com (Jesse Barnes) Date: Wed, 24 Sep 2003 18:21:51 +0000 Subject: Re: [PATCH] do_gettimeofday() fails to compensate for lost ticks Message-Id: List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org On Wed, Sep 24, 2003 at 12:17:41PM -0600, Khalid Aziz wrote: > > This explanation doesn't sound right. See the "lost" variable in > > gettimeoffset(). It's supposed to account for lost ticks. > > > > --david > > David, > > So it would seem. What would then explain clock going backwards? Here is > what I see when the test fails: > > tpget37128357,995121000, tpset37128358,0 > > where tpget is what was returned by gettimeofday() and tpset is what was > set by settimeofday(). Clock seems to have moved back by 4.879 msec. Just FYI, Martin Hicks noticed recently that 2.6 on a machine with itc drift also has this problem. I think John Hawkes has some ideas on how to fix it, but I haven't had time to look at it yet. Thanks, Jesse