On Fri, Sep 18, 2020 at 09:27:23AM +0200, David Hildenbrand wrote: >On 18.09.20 04:07, Wei Yang wrote: >> On Wed, Sep 16, 2020 at 08:34:09PM +0200, David Hildenbrand wrote: >>> __putback_isolated_page() already documents that pages will be placed to >>> the tail of the freelist - this is, however, not the case for >>> "order >= MAX_ORDER - 2" (see buddy_merge_likely()) - which should be >>> the case for all existing users. >>> >>> This change affects two users: >>> - free page reporting >>> - page isolation, when undoing the isolation. >>> >>> This behavior is desireable for pages that haven't really been touched >>> lately, so exactly the two users that don't actually read/write page >>> content, but rather move untouched pages. >>> >>> The new behavior is especially desirable for memory onlining, where we >>> allow allocation of newly onlined pages via undo_isolate_page_range() >>> in online_pages(). Right now, we always place them to the head of the >> >> The code looks good, while I don't fully understand the log here. >> >> undo_isolate_page_range() is used in __offline_pages and alloc_contig_range. I >> don't connect them with online_pages(). Do I miss something? > >Yeah, please look at -mm / -next instead. See > >https://lkml.kernel.org/r/20200819175957.28465-11-david@xxxxxxxxxx > Thanks, I get the point. > >-- >Thanks, > >David / dhildenb -- Wei Yang Help you, Help me
