Re: [PATCH 0/4] Lumpy Reclaim V3

[Andy Whitcroft <apw@shadowen.org>]

Andrew Morton wrote:
> On Wed, 6 Dec 2006 16:59:04 +0000
> Andy Whitcroft <apw@shadowen.org> wrote:
> 
>> This is a repost of the lumpy reclaim patch set.
> 
> more...
> 
> One concern is that when the code goes to reclaim a lump and fails, we end
> up reclaiming a number of pages which we didn't really want to reclaim. 
> Regardless of the LRU status of those pages.
> 
> I think what we should do here is to add the appropriate vmstat counters
> for us to be able to assess the frequency of this occurring, then throw a
> spread of workloads at it.  If that work indicates that there's a problem
> then we should look at being a bit smarter about whether all the pages look
> to be reclaimable and if not, restore them all and give up.
> 
> Also, I suspect it would be cleaner and faster to pass the `active' flag
> into isolate_lru_pages(), rather than calculating it on the fly.  And I
> don't think we need to calculate it on every pass through the loop?
> 
> 
> We really do need those vmstat counters to let us see how effective this
> thing is being.  Basic success/fail stuff.  Per-zone, I guess.


Sounds like a cue ... I'll go do that.

-apw