On Mon, Jul 07, 2014 at 05:50:09PM +0200, Vlastimil Babka wrote: > On 07/04/2014 09:57 AM, Joonsoo Kim wrote: > >Currently, when we free the page from pcp list to buddy, we check > >pageblock of the page in order to isolate the page on isolated > >pageblock. Although this could rarely happen and to check migratetype of > >pageblock is somewhat expensive, we check it on free fast path. I think > >that this is undesirable. To prevent this situation, I introduce new > >variable, nr_isolate_pageblock on struct zone and use it to determine > >if we should check pageblock migratetype. Isolation on pageblock rarely > >happens so we can mostly avoid this pageblock migratetype check. > > Better, but still there's a zone flag check and maintenance. So if > it could be avoided, it would be better. > > >Additionally, unify freepage counting code, because it can be done in > >common part, __free_one_page(). This unifying provides extra guarantee > >that the page on isolate pageblock don't go into non-isolate buddy list. > >This is similar situation describing in previous patch so refer it > >if you need more explanation. > > You should make it clearer that you are solving misplacement of the > type "page should be placed on isolated freelist but it's not" > through free_one_page(), which was solved only for > free_pcppages_bulk() in patch 03/10. Mentioning patch 04/10 here, > which solves the opposite problem "page shouldn't be placed on > isolated freelist, but it is", only confuses the situation. Also > this patch undoes everything of 04/10 and moves it elsewhere, so > that would make it harder to git blame etc. I would reorder 04 and > 05. Okay. I will clarify what I am solving in commit description and reorder patches appropriately. Thanks. -- 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>