Messages in this thread | | | Date | Thu, 25 May 2006 19:33:36 -0700 (PDT) | From | Christoph Lameter <> | Subject | Re: [PATCH 1/3] mm: tracking shared dirty pages |
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On Thu, 25 May 2006, Jeff Anderson-Lee wrote:
> Christoph Lameter wrote: > > > I am a bit confused about the need for Davids patch. set_page_dirty() is > > already a notification that a page is to be dirtied. Why do we need it > > twice? set_page_dirty could return an error code and the file system can > > use the set_page_dirty() hook to get its notification. What we would need > > to do is to make sure that set_page_dirty can sleep. > > set_page_dirty() is actually called fairly late in the game by > zap_pte_range() and follow_page(). Thus, it is a notification that a page > HAS BEEN dirtied and needs a writeback.
The tracking patch changes that behavior. set_page_dirty is called before the write to the page occurs and so its similar to the new method introduced by David's patch.
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