Messages in this thread | | | Date | Fri, 18 Jul 2014 17:12:54 +0200 | Subject | Re: [patch 13/13] mm: memcontrol: rewrite uncharge API | From | Miklos Szeredi <> |
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On Fri, Jul 18, 2014 at 4:45 PM, Johannes Weiner <hannes@cmpxchg.org> wrote:
> I assumed the source page would always be new, according to this part > in fuse_try_move_page(): > > /* > * This is a new and locked page, it shouldn't be mapped or > * have any special flags on it > */ > if (WARN_ON(page_mapped(oldpage))) > goto out_fallback_unlock; > if (WARN_ON(page_has_private(oldpage))) > goto out_fallback_unlock; > if (WARN_ON(PageDirty(oldpage) || PageWriteback(oldpage))) > goto out_fallback_unlock; > if (WARN_ON(PageMlocked(oldpage))) > goto out_fallback_unlock; > > However, it's in the page cache and I can't really convince myself > that it's not also on the LRU. Miklos, I have trouble pinpointing > where oldpage is instantiated exactly and what state it might be in - > can it already be on the LRU?
oldpage comes from ->readpages() (*NOT* ->readpage()), i.e. readahead.
AFAICS it is added to the LRU in read_cache_pages(), so it looks like it is definitely on the LRU at that point.
Thanks, Miklos
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