| |
|
 |
|
 |
|
|
|
| |
|
|
xen-devel
RE: [Xen-devel] [PATCH] linux/balloon: don't allow ballooningdowna domai
> Can't vm_committed_space grow *bigger* than available memory
> when using
> swap? It may indicate the 'static' demand for memory (in
> terms of requested
> allocations so far) but we're interested in dynamic demand
> (how much of that
> allocated memory is actually used), which afaics
> vm_committed_space doesn't
> appear very useful for.
>
> Some indication of paging churn, or average age of pages in memory, or
> something like that, would seem more useful (albeit
> arbitrarily harder to
> work out from within the balloon driver!).
>
> Maybe I'm missing something. I've only had a quick look at usage of
> vm_committed_space.
You are right about vm_committed_space growing bigger. I was
too terse: I was trying to use it in a min(x,y,z) calculation
with the existing algorithm, but apparently it becomes too small
sometimes (e.g. during shutdown) and I observed OOM problems.
However vm_committed_space seems to be a pretty good dynamic demand
indicator in general. Try watch'ing it in a window while doing
other tasks on a machine/VM, e.g.:
watch grep Committed_AS /proc/meminfo
It grows rapidly when memory hogs are launched and shrinks
rapidly when the machine goes idle. So it seems to work
well for at least a first approximation for selfballooning.
Dan
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel
|
|
|
| |
|
Home