Re: [patch] Prevent excessive xfsaild wakeups

[David Chinner <dgc@sgi.com>]

On Wed, Feb 20, 2008 at 02:10:00PM -0500, Christoph Hellwig wrote:
> On Tue, Feb 19, 2008 at 09:59:06AM +1100, David Chinner wrote:
> > +	if (count && (XFS_LSN_CMP(lsn, target) >= 0)) {
> > +		/*
> > +		 * We reached the target so wait a bit longer for I/O to
> > +		 * complete and remove pushed items from the AIL before we
> > +		 * start the next scan from the start of the AIL.
> > +		 */
> >  		tout += 20;
> >  		last_pushed_lsn = 0;
> > +	} else if (!count) {
> > +		/* We're past our target or empty, so idle */
> > +		tout = 1000;
> >  	} else if ((restarts > XFS_TRANS_PUSH_AIL_RESTARTS) ||
> >  		   (count && ((stuck * 100) / count > 90))) {
> >  		/*
> 
> When looking at this conditions it confuses the hell out of me.  Having
> count checked in each of three nested conditionals simply isn't readable
> :)

Yeah, I noticed that when posting it. Got to keep you busy, Christoph. ;)

> Also some checks seem to be superflous, so how about:

Yup, fixed to be like this. I'll run it through a qa run
and go from there...

Cheers,

Dave.
-- 
Dave Chinner
Principal Engineer
SGI Australian Software Group