Re: aio-stress throughput regressions from 2.6.11 to 2.6.12

[Sébastien Dugué]

On Fri, 2005-07-01 at 13:26 +0530, Suparna Bhattacharya wrote:
> Has anyone else noticed major throughput regressions for random
> reads/writes with aio-stress in 2.6.12 ?
> Or have there been any other FS/IO regressions lately ?
> 
> On one test system I see a degradation from around 17+ MB/s to 11MB/s
> for random O_DIRECT AIO (aio-stress -o3 testext3/rwfile5) from 2.6.11
> to 2.6.12. It doesn't seem filesystem specific. Not good :(
> 
> BTW, Chris/Ben, it doesn't look like the changes to aio.c have had an impact
> (I copied those back to my 2.6.11 tree and tried the runs with no effect)
> So it is something else ...
> 
> Ideas/thoughts/observations ?
> 
> Regards
> Suparna
> 

  I'm too seeing a regression, but between 2.6.10 and 2.6.12 and using
sysbench + MySQL (with POSIX AIO). The difference is roughly 8% slower
for 2.6.12. I'm currently trying to trace it.

  aio-stress shows no difference so it probably does not come from
kernel AIO.

  Sébastien.


-- 
------------------------------------------------------

  Sébastien Dugué                BULL/FREC:B1-247
  phone: (+33) 476 29 77 70      Bullcom: 229-7770

  mailto:sebastien.dugue@xxxxxxxx

  Linux POSIX AIO: http://www.bullopensource.org/posix
  
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