On Thu, Aug 07, 2014 at 03:49:17PM +0200, Vlastimil Babka wrote: > On 08/06/2014 09:18 AM, Joonsoo Kim wrote: > >The check '!PageBuddy(page) && page_count(page) == 0 && > >migratetype == MIGRATE_ISOLATE' would mean the page on free processing. > > What is "the page on free processing"? I thought this test means the > page is on some CPU's pcplist? Yes, you are right. > > >Although it could go into buddy allocator within a short time, > >futher operation such as isolate_freepages_range() in CMA, called after > >test_page_isolated_in_pageblock(), could be failed due to this unstability > > By "unstability" you mean the page can be allocated again from the > pcplist instead of being freed to buddy list? Yes. > >since it requires that the page is on buddy. I think that removing > >this unstability is good thing. > > > >And, following patch makes isolated freepage has new status matched with > >this condition and this check is the obstacle to that change. So remove > >it. > > You could also say that pages from isolated pageblocks can no longer > appear on pcplists after the later patches. Okay. I will do it. 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>