On Wed 08-06-16 09:34:01, Dave Hansen wrote: > 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... exactly and that is why I am not sure it is needed. I do not expect we would ever change the pagevec size or have a different way of grouping pages on the LRU list. That being said I am not objecting to the counter, I am just not sure it is worth it. > for one of the 5 classes of pvecs. > > Is there a good reason we don't have to touch the other 4 pagevecs, btw? I agree it would be better to do the same for others as well. Even if this is not an immediate problem for those. -- Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>