Re: [PATCH 0/14] Avoid overflowing of stack during page reclaim V3

[Andrew Morton]

On Tue, 29 Jun 2010 12:34:34 +0100
Mel Gorman <mel@xxxxxxxxx> wrote:

> Here is V3 that depends again on flusher threads to do writeback in
> direct reclaim rather than stack switching which is not something I'm
> likely to get done before xfs/btrfs are ignoring writeback in mainline
> (phd sucking up time).

IMO, implemetning stack switching for this is not a good idea.  We
_already_ have a way of doing stack-switching.  It's called
"schedule()".

The only reason I can see for implementing an in-place stack switch
would be if schedule() is too expensive.  And if we were to see
excessive context-switch overheads in this code path (and we won't)
then we should get in there and try to reduce the contect switch rate
first.

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