Re: [PATCH 4/5] xfs: speed up directory bestfree block scanning

[Christoph Hellwig <hch@infradead.org>]

On Thu, Aug 29, 2019 at 06:45:30PM +1000, Dave Chinner wrote:
> > 
> > The label rename while more descriptive also seems entirely unrelated.
> 
> That was one of your previous suggestions :)
> 
> I'll push it back up one patch into the cleanup patch and leave this
> as an optimisation only patch.

Oh well.  Just keep it then :)

> > > +		/* Scan the free entry array for a large enough free space. */
> > > +		do {
> > > +			if (be16_to_cpu(bests[findex]) != NULLDATAOFF &&
> > > +			    be16_to_cpu(bests[findex]) >= length) {
> > > +				dbno = freehdr.firstdb + findex;
> > > +				goto found_block;
> > >  			}
> > > +		} while (++findex < freehdr.nvalid);
> > 
> > Nit: wou;dn't this be better written as a for loop also taking the
> > initialization of findex into the loop?
> 
> Agreed - the next patch does that with the reversal of the search
> order. The end result is what you're asking for, so I'll leave this
> alone for now....

If you touch this patch anyway please just switch to the for loop
here, that keeps the churn down in the next one.