Re: [BENCHMARK] 2.5.39 with contest 0.41

Jens Axboe
2002-09-28T09:03:10Z

On Sat, Sep 28 2002, Con Kolivas wrote:
> > > io_load:
> > > Kernel Time CPU Ratio
> > > 2.4.19 216.05 33% 3.19
> > > 2.5.38 887.76 8% 13.11*
> > > 2.5.38-mm3 105.17 70% 1.55*
> > > 2.5.39 216.81 37% 3.20
> >
> > -mm3 has fifo_batch=16. 2.5.39 has fifo_batch=32.

That's not the only difference, btw.

> > > mem_load:
> > > Kernel Time CPU Ratio
> > > 2.4.19 105.40 70% 1.56
> > > 2.5.38 107.89 73% 1.59
> > > 2.5.38-mm3 117.09 63% 1.73*
> > > 2.5.39 103.72 72% 1.53
> >
> > 2.5's swapout is still fairly synchronously sucky. So low-latency
> > writeout could be advantageous there. This difference is probably
> > also the fifo_batch thing. Or maybe statistical?
> >
> >
> > I did some testing with your latest. 4xPIII, mem=512m, SCSI,
> > tag depth = 0, 2.5.39-mm1 candidate:
> >
> > fifo_batch=32:
> >
> > noload 2:34.53 291%
> > cpuload 2:36.20 286%
> > memload 2:19.44 333%
> > ioloadhalf 2:34.81 303%
> > ioloadfull 3:15.47 238%
> >
> > (err. memload sped it up!)
> >
> > fifo_batch=16:
> >
> > noload 2:00.03 380%
> > cpuload 2:27.62 304%
> > memload 2:22.59 326%
> > ioloadhalf 2:33.75 306%
> > ioloadfull 2:59.18 259%
> >
> > - Something went horridly wrong in the first `noload' test.
> > - fifo_batch=16 is better than 32.
> > - you see a 4x hit from io_load. I see a 1.5x hit.

So far fifo_batch=16 looks pretty good. Doesn't quite make sense to me.
Need to bench/test some more :-)

--
Jens Axboe