Re: XFS unlink still slow on 3.1.9 kernel ?

Richard Ems
2012-02-13T17:53:23Z

On 02/13/2012 06:29 PM, Christoph Hellwig wrote:
> On Mon, Feb 13, 2012 at 06:26:46PM +0100, Richard Ems wrote:
>> YES. All files (and dirs) that I checked do show something as
>>
>> 0: [0..7]: 18531216..18531223
>>
>> So, what improvements can I expect from a kernel > 3.2 ?
>> Can I read somewhere about the changes/patches introduced?
>
> On some crazy workloads I've seen speedups up to a factor of 10.000 (5
> orders or magnitude). You probably won't get that much of a speedup,
> but it will still be significant.
>
> The patch in mainline for this is:
>
> commit 859f57ca00805e6c482eef1a7ab073097d02c8ca
> Author: Christoph Hellwig <hch@infradead.org>
> Date: Sat Aug 27 14:45:11 2011 +0000
>
> xfs: avoid synchronous transactions when deleting attr blocks
>
>> Is there another way to mount/create/mkfs the XFS to improve the unlink
>> time for this case?
>
> Try increasing the inode size during filesystem creating using the
> "-i size=512" option or even "-i size=1024" if you still have
> out of line attributes. The should give you even bigger speedups
> for this workload than the patch above.
>

Ok, Many thanks for this good info!

I will try to install a > 3.2 kernel and will create new XFS partitions
with "-i size=1024", since we use ACLs a lot for user access.
Is there a chance to change existing XFS partitions to "-i size=1024" ?
I already have 5 big partitions, all full of ACLs and not running
kernels > 3.2 !

Many thanks again,
Richard