Messages in this thread | | | From | Nick Piggin <> | Subject | Re: [PATCH] mm fix page writeback accounting to fix oom condition under heavy I/O | Date | Tue, 10 Feb 2009 16:56:13 +1100 |
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On Tuesday 10 February 2009 16:23:56 Linus Torvalds wrote: > On Mon, 9 Feb 2009, Mathieu Desnoyers wrote: > > So this patch fixes this behavior by only decrementing the page > > accounting _after_ the block I/O writepage has been done. > > This makes no sense, really. > > Or rather, I don't mind the notion of updating the counters only after IO > per se, and _that_ part of it probably makes sense. But why is it that you > only then fix up two of the call-sites. There's a lot more call-sites than > that for this function.
Well if you do that, then I'd think you also have to change some calculations that today use dirty+writeback.
In some ways it does make sense, but OTOH it is natural in the pagecache since it was introduced to treat writeback as basically equivalent to dirty. So writeback && !dirty pages shouldn't cause things to blow up, or if it does then hopefully it is a simple bug somewhere.
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