On Tue, 3 Jan 2012 19:22:42 -0800 (PST)
Hugh Dickins [off-list ref] wrote:

quoted

quoted

quoted

Now, a way out here is to remove lumpy reclaim (please).  And make the
problem not come back by promising to never call putback_lru_pages(lots
of pages) (how do we do this?).

We can very easily put a counter in it, doing a spin_unlock_irq every
time we hit the max.  Nothing prevents that, it's just an excrescence
I'd have preferred to omit and have not today implemented.

Yes.  It's ultra-cautious, but perhaps we should do this at least until
lumpy goes away.

I don't think you'll accept my observations above as excuse to do
nothing, but please clarify which you think is more cautious.  Should
I or should I not break up the isolating end in the same way as the
putting back?

If we already have the latency problem at the isolate_lru_pages() stage
then I suppose we can assume that nobody is noticing it, so we'll
probably be OK.

For a while.  Someone will complain at some stage and we'll probably
end up busting this work into chunks.

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>