Subject: Re: [PATCH] New x86_64 time code for 2.5.70
From: john stultz <johnstul@us.ibm.com>
To: "Bryan O'Sullivan" <bos@serpentine.com>
Cc: Andi Kleen <ak@suse.de>, vojtech@suse.cz, discuss@x86-64.org,
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Date: 11 Jun 2003 14:41:31 -0700
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On Wed, 2003-06-11 at 14:36, Bryan O'Sullivan wrote:
> On Wed, 2003-06-11 at 14:23, john stultz wrote:
> 
> > Hmmm. Thats likely part to blame for the lost-ticks code not working. I
> > believe tick_usec is calculated USER_HZ rather then HZ, so you'll be off
> > by an order of magnitude. I ran into the exact same problem. 
> 
> Unlikely.  On my systems, the offset values are off by three orders of
> magnitude, and are always negative.  There's a more basic error
> somewhere before that test.

Ok, that was just the first thing I noticed. Let me dig in and see what
I can find. 


> The actual impact of lost jiffies is pretty low, though.  I've beaten
> vigorously on my systems with the time patch, and they don't lose timer
> interrupts.

Hmm. In my (very quick) testing I'm seeing very frequent 10,000us
inconsistencies. This is w/ and w/o the vsyscall code enabled, so I'm
not sure whats causing it yet. I'll let you know if I trip over
anything.

thanks
-john

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