Re: [PATCH, RFC] Move AIL pushing into a separate thread

[Christoph Hellwig <hch@xxxxxxxxxxxxx>]

On Fri, Nov 16, 2007 at 11:43:10AM +1100, David Chinner wrote:
> > >+          /* Too many items we can't do anything with? */
> > >+          if (stuck > 100)
> > 100?  Arbitrary magic number or was there reason for this?
> 
> Arbitrary magic number based on observation. basically, if
> we are skipping too many items because we can't flush them or
> they are already being flushed we back off and given them time
> to complete whatever operation is being done. i.e. remove pressure
> from the AIL while we can't make progress so traversals don't
> slow down further inserts and remov?ls to/from the AIL.

Might be worth adding something like this as a comment.