From mboxrd@z Thu Jan  1 00:00:00 1970
From: Dave Winchell <dwinchell@virtualiron.com>
Subject: Re: [PATCH] Add a timer mode that disables pending missed
	ticks
Date: Thu, 08 Nov 2007 10:08:23 -0500
Message-ID: <47332667.1090701@virtualiron.com>
References: <C358D357.181CD%Keir.Fraser@cl.cam.ac.uk>
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To: Keir Fraser <Keir.Fraser@cl.cam.ac.uk>
Cc: "Shan, Haitao" <haitao.shan@intel.com>, Dave Winchell <dwinchell@virtualiron.com>, xen-devel@lists.xensource.com, "Dong,
	Eddie" <eddie.dong@intel.com>, "Jiang, Yunhong" <yunhong.jiang@intel.com>
List-Id: xen-devel@lists.xenproject.org

ok, I'll try your new code and let you know what
I find.

-Dave

Keir Fraser wrote:

>On 8/11/07 14:43, "Dave Winchell" <dwinchell@virtualiron.com> wrote:
>
>  
>
>>I agree that this could be a problem. I have an idea that could give us full
>>SYNC and eliminate the long periods without clock interrupts.
>>In pt_process_missed_ticks() when missed_ticks > 0 set pt->run_timer = 1.
>>In pt_save_timer():
>>
>>    list_for_each_entry ( pt, head, list )
>>        if(!pt->run_timer)
>>             stop_timer(&pt->timer);
>>
>>And in pt_timer_fn():
>>
>>    pt->run_timer = 0;
>>
>>So, for a guest that misses a tick, we will interrupt him once from the
>>descheduled state and then leave him alone in the descheduled state.
>>    
>>
>
>Well, I'd rather not complicate the code if it's avoidable. I checked in a
>SYNC/ASYNC combo and code simplification as changeset 16341, and it'd be
>interesting to know how that fares against your suggested scheme. I suppose
>as long as we're better than ntpd's tolerance it doesn't actually matter all
>that much.
>
> -- Keir
>
>
>  
>