Re: freemem-slack and large memory environments

[Mike Latimer <mlatimer@suse.com>]

On Friday, February 27, 2015 10:52:17 AM Stefano Stabellini wrote:
> On Thu, 26 Feb 2015, Mike Latimer wrote:
> >    libxl_set_memory_target = 1
> 
> The new memory target is set for dom0 successfully.
> 
> >    libxl_wait_for_free_memory = -5
> 
> Still there isn't enough free memory in the system.
> 
> >    libxl_wait_for_memory_target = 0
> 
> However dom0 reached the new memory target already.
> Who is stealing your memory?

I just realized I was missing commit 2048aeec, which corrects the hardcoded 
return value of libxl_wait_for_memory_target from 0 to rc. I'll retest with 
this change in place.

> In any case in the context of libxl_wait_for_memory_target, ERROR_FAIL
> means that the memory target has not been reached.

I'm expecting this commit to to change what I'm seeing, but I'm not convinced 
it will be a good change...  There is zero chance dom0 will balloon down 64GB 
(or 512GB) in the 10 second window set by freemem. This will likely mean the 
entire process will fail (when given a bit more time it would have succeeded).

I'll add the missing commit, and send a complete set of debug logs later 
today.

-Mike