Re: The performance and behaviour of the anti-fragmentation related patches

Bill Irwin
2007-03-02T21:39:25Z

At some point in the past, Mel Gorman wrote:
>> I can't think of a workload that totally makes a mess out of list-based.
>> However, list-based makes no guarantees on availability. If a system
>> administrator knows they need between 10,000 and 100,000 huge pages and
>> doesn't want to waste memory pinning too many huge pages at boot-time,
>> the zone-based mechanism would be what he wanted.

On Fri, Mar 02, 2007 at 10:31:39AM -0600, Joel Schopp wrote:
> From our testing with earlier versions of list based for memory hot-unplug
> on pSeries machines we were able to hot-unplug huge amounts of memory after
> running the nastiest workloads we could find for over a week. Without the
> patches we were unable to hot-unplug anything within minutes of running the
> same workloads.
> If something works for 99.999% of people (list based) and there is an easy
> way to configure it for the other 0.001% of the people ("zone" based) I
> call that a great solution. I really don't understand what the resistance
> is to these patches.

Sorry if I was unclear; I was anticipating others' objections and
offering to assist in responding to them. I myself have no concerns
about the above strategy, apart from generally wanting to recover the
list-based patch's hugepage availability without demanding it as a
merging criterion.

-- wli