Re: Some baseline tests on new hardware (was Re: [PATCH] xfs: optimise CIL insertion during transaction commit [RFC])

[Dave Chinner <david@fromorbit.com>]

On Tue, Jul 09, 2013 at 08:43:32AM +0800, Zheng Liu wrote:
> Hi Dave,
> 
> On Mon, Jul 08, 2013 at 10:44:53PM +1000, Dave Chinner wrote:
> [...]
> > So, lets look at ext4 vs btrfs vs XFS at 16-way (this is on the
> > 3.10-cil kernel I've been testing XFS on):
> > 
> > 	    create		 walk		unlink
> > 	 time(s)   rate		time(s)		time(s)
> > xfs	  222	266k+-32k	  170		  295
> > ext4	  978	 54k+- 2k	  325		 2053
> > btrfs	 1223	 47k+- 8k	  366		12000(*)
> > 
> > (*) Estimate based on a removal rate of 18.5 minutes for the first
> > 4.8 million inodes.
> > 
> > Basically, neither btrfs or ext4 have any concurrency scaling to
> > demonstrate, and unlinks on btrfs a just plain woeful.
> > 
> > ext4 create rate is limited by the extent cache LRU locking:
> 
> I have a patch to fix this problem and the patch has been applied into
> 3.11-rc1.  The patch is (d3922a77):
>   ext4: improve extent cache shrink mechanism to avoid to burn CPU time
> 
> I do really appreicate that if you could try your testing again against
> this patch.  I just want to make sure that this problem has been fixed.
> At least in my own testing it looks fine.

I'll redo them when 3.11-rc1 comes around. I'll let you know how
much better it is, and where the next ring of the onion lies.

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com