On Mon, 18 Jul 2011, Mel Gorman wrote:

> > We may be able to simplify the function by:
> >
> > 1.  Checking for the special case that the first zone is ok and that we do
> > not want to call zlc_setup before we get to the loop.
> >
> > 2. Do the zlc_setup() before the loop.
> >
> > 3. Remove the zlc_setup() code as you did from the loop as well as the
> > checks for zlc_active. zlc_active becomes not necessary since a zlc
> > is always available when we go through the loop.
> >
>
> That initial test will involve duplication of things like the cpuset and
> no watermarks check just to place the zlc_setup() in a different place.
> I might be missing your point but it seems like the gain would be
> marginal. Fancy posting a patch?

Looked at it for some time. Would have to create a new function for the
watermark checks, the call to buffer_rmqueue and the marking of a zone as
full. After that the goto mess could be unraveled. But I am out of time
for today.