On 06/08/2016 09:06 AM, Michal Hocko wrote: >> > Do we have any statistics that tell us how many pages are sitting the >> > lru pvecs? Although this helps the problem overall, don't we still have >> > a problem with memory being held in such an opaque place? > Is it really worth bothering when we are talking about 56kB per CPU > (after this patch)?
That was the logic why we didn't have it up until now: we didn't *expect* it to get large. A code change blew it up by 512x, and we had no instrumentation to tell us where all the memory went. I guess we don't have any other ways to group pages than compound pages, and _that_ one is covered now... for one of the 5 classes of pvecs. Is there a good reason we don't have to touch the other 4 pagevecs, btw?