[PATCH 2/2] xfs: reclaim all inodes by background tree walks

[Dave Chinner]

On Fri, Jan 08, 2010 at 05:24:08AM -0500, Christoph Hellwig wrote:
> 
> Looks safe to me.  I wonder whaimpact leaving the inodes around for
> longer has to memory usage for inode heavy workloads, though.

In terms of wall time, nothing I can measure, but it seems to reduce
system time slightly. My main concern is memory pressure - maybe it
needs a shrinker registered to reclaim inodes immediately rather
than waiting for the next xfsssyncd run...

> >  unlock_and_requeue:
> > +	/*
> > +	 * We could return EAGAIN here to make reclaim rescan the inode tree in
> > +	 * a short while. However, this just burns CPU time scanning the tree
> > +	 * waiting for IO to complete and xfssyncd never goes back to the idle
> > +	 * state. Instead, return 0 to let the next scheduled background reclaim
> > +	 * attempt to reclaim the inode again.
> > +	 */
> >  	xfs_iflags_clear(ip, XFS_IRECLAIM);
> >  	xfs_iunlock(ip, XFS_ILOCK_EXCL);
> > -	return EAGAIN;
> > +	return 0;
> 
> This is an unrelated change and should be a patch of it's own.

Yup.

Cheers,

Dave.
-- 
Dave Chinner
david at fromorbit.com