Messages in this thread | | | Date | Mon, 12 Sep 2011 10:34:34 +0100 | From | Mel Gorman <> | Subject | Re: [PATCH 03/10] mm: Add support for a filesystem to control swap files |
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On Mon, Sep 12, 2011 at 11:04:45AM +0200, Peter Zijlstra wrote: > On Fri, 2011-09-09 at 09:36 -0400, Christoph Hellwig wrote: > > The equivalent of ->direct_IO should be used for both reads and writes. > > So the difference between DIO and swapIO is that swapIO needs the block > map pinned in memory.. So at the very least you'll need those > swap_{activate,deactivate} aops. The read/write-page thingies could > indeed be shared with DIO. >
I'm travelling at the moment so it'll be later in the week when I investigate properly but I agree swap_[de|a]ctivate are still necessary. NFS does not need to pin a block map but it's still necessary for calling xs_set_memalloc.
-- Mel Gorman SUSE Labs
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