Re: [CALL FOR TESTING] Make Ext3 fsck way faster [2.6.24-rc6 -mm patch]

["Abhishek Rai" <abhishekrai@google.com>]

No, it didn't. I measured read from a 10GB sequentially laid out file
with standard benchmarking practices (cold cache, multiple runs, low
std. deviation in results, etc.) and here are the results:

File created by vanilla Ext3 being read by vanilla Ext3:
Total: 3m16.1s
User: 0.0.5s
Sys: 13.9

File created by mc Ext3 being read by mc Ext3 (with the buffer
boundary logic disabled):
Total: 3m15.5s
User: 0.05s
Sys: 13.6s

Thanks,
Abhishek

On Jan 24, 2008 2:49 AM, Andrew Morton <akpm@linux-foundation.org> wrote:
> > On Wed, 23 Jan 2008 04:12:16 -0500 Abhishek Rai <abhishekrai@google.com> wrote:
> > > I'm wondering about the interaction between this code and the
> > > buffer_boundary() logic.  I guess we should disable the buffer_boundary()
> > > handling when this code is in effect.  Have you reviewed and tested that
> > > aspect?
> >
> > Thanks for pointing this out, I had totally missed this issue in my change. I've now made the call to set_buffer_boundary() in ext3_get_blocks_handle() subject to metacluster option being set.
> >
>
> Did it make any performance difference?  iirc the buffer_boundary stuff was
> worth around 10% on a single linear read of a large, well-laid-out file.
>