Re: freemem-slack and large memory environments

[Ian Campbell <ian.campbell@citrix.com>]

On Thu, 2015-02-26 at 08:36 -0700, Mike Latimer wrote:
> On Wednesday, February 25, 2015 02:09:50 PM Stefano Stabellini wrote:
> > > Is the upshot that Mike doesn't need to do anything further with his
> > > patch (i.e. can drop it)? I think so?
> > 
> > Yes, I think so. Maybe he could help out testing the patches I am going
> > to write :-)
> 
> Sorry for not responding to this yesterday.
> 
> There is still one aspect of my original patch that is important. As the code 
> currently stands, the target for dom0 is set lower during each iteration of 
> the loop. Unless only one iteration is required, dom0 will end up being set to 
> a much lower target than is actually required.

Is this because some sort of slack is applied once per iteration rather
than once at the start or is it something else?

> 
> There are two ways to fix this issue:
> 
>  - Set the memory target for dom0 once, before entering the loop
>  - During each iteration of the loop, compare the amount of needed memory to 
> the amount of memory which will be available once dom0 hits the target, and 
> only lower the target if additional memory is needed.
> 
> My patch earlier in this thread does the former, but I think the second option 
> is also possible. Is there a preference between those approaches (or a better 
> idea)?
> 
> Thanks,
> Mike
> 
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