Messages in this thread |  | | Date | Mon, 17 Sep 2001 08:42:35 -0700 (PDT) | From | Linus Torvalds <> | Subject | Re: broken VM in 2.4.10-pre9 |
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On Mon, 17 Sep 2001, Rik van Riel wrote: > > > - I don't like the lack of aging in 'reclaim_page()'. It will walk the > > whole LRU list if required, which kind of defeats the purpose of having > > reference bits and LRU on that list. The code _claims_ that it almost > > always succeeds with the first page, but I don't see why it would. I > > think that comment assumed that the inactive_clean list cannot have any > > referenced pages, but that's never been true. > > This depends on whether we do reactivation in __find_page_nolock() > or if we leave the page alone and wait for kswapd to do that for > us.
We should not do _anything_ in __find_page_nolock().
It's positively wrong to touch any aging information there - if you do, you are guaranteed to not get read-ahead right (ie a page that gets read-ahead first will behave differently than a page that got read directly, which just cannot be right).
The aging has to be done at a higher level (ie when you actually _use_ it, not when you search the hash queues).
Linus
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