Re: [PATCH 4/4] Add a timer to allow the separation of consigned from steal time.

[Glauber Costa <glommer@parallels.com>]

On 02/06/2013 10:07 PM, Michael Wolf wrote:
> On 02/06/2013 08:36 AM, Glauber Costa wrote:
>> On 02/06/2013 01:49 AM, Michael Wolf wrote:
>>> Add a helper routine to scheduler/core.c to allow the kvm module
>>> to retrieve the cpu hardlimit settings.  The values will be used
>>> to set up a timer that is used to separate the consigned from the
>>> steal time.
>> Sorry: What is the business of a timer in here?
>> Whenever we read steal time, we know how much time has passed and with
>> that information we can know the entitlement for the period. This breaks
>> if we suspend, but we know that we suspended, so this is not a problem.
> I may be missing something, but how do we know how much time has
> passed?  That is why
> I had the timer in there.  I will go look again at the code but I
> thought the data was collected
> as ticks and passed at random times.  The ticks are also accumulating so
> we are looking at the
> difference in the count between reads.....

They can be collected at random times, but you can of course record the
time in which it happened.