Messages in this thread | | | Date | Thu, 23 Jul 2009 12:43:25 +0100 (BST) | From | Hugh Dickins <> | Subject | Re: [PATCH 06/10] ksm: identify PageKsm pages |
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On Thu, 23 Jul 2009, KAMEZAWA Hiroyuki wrote: > On Wed, 22 Jul 2009 13:54:06 +0100 (BST) > Hugh Dickins <hugh.dickins@tiscali.co.uk> wrote: > > > > (At this instant I've forgotten why there's an unevictable list at > > all - somewhere in vmscan.c which is accustomed to dealing with > > pages on lists, so easier to have them on a list than not?) > > > I forget, too. But in short thinking, Unevictable pages should be > on LRU (marked as PG_lru) for isolating page (from LRU) called by > page migration etc. > > isolate_lru_page() > -> put page on private list > -> do some work > -> putback_lru_page() > > sequence is useful at handling pages in a list. > Because mlock/munclock can be called arbitrarily, unevicatable lru > works enough good for making above kinds of code simpler.
Yes, I think that's it, thanks.
And for the moment, the KSM pages are therefore unmigratable as well as unswappable; but that should change in 2.6.33.
Hugh
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