On Wed 25-02-15 09:27:28, Minchan Kim wrote: > On Tue, Feb 24, 2015 at 05:14:08PM +0100, Michal Hocko wrote: > > On Tue 24-02-15 17:18:16, Minchan Kim wrote: > > > MADV_FREE is hint that it's okay to discard pages if memory is > > > pressure and we uses reclaimers(ie, kswapd and direct reclaim) > > > > s@if memory is pressure@if there is memory pressure@ > > > > > to free them so there is no worth to remain them in active > > > anonymous LRU list so this patch moves them to inactive LRU list. > > > > Makes sense to me. > > > > > A arguable issue for the approach is whether we should put it > > > head or tail in inactive list > > > > Is it really arguable? Why should active MADV_FREE pages appear before > > those which were living on the inactive list. This doesn't make any > > sense to me. > > It would be better to drop garbage pages(ie, freed from allocator) > rather than swap out and now anon LRU aging is seq model so > inacitve list can include a lot working set so putting hinted pages > into tail of LRU could enhance reclaim efficiency. > That's why I said it might be arguble. OK, maybe I misunderstood what you tried to tell. Sure we can discuss whether to put all MADV_FREE pages to the tail of inactive list. But the above wording suggested that _active_ MADV_FREE pages were discussed and treating them differently from the inactive pages simply didn't make sense to me. [...] -- 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>