Re: [BENCHMARK] 2.5.47{-mm1} with contest

[Andrew Morton <akpm@digeo.com>]

Con Kolivas wrote:
> 
> io_load:
> Kernel [runs]           Time    CPU%    Loads   LCPU%   Ratio
> 2.4.18 [3]              474.1   15      36      10      6.64
> 2.4.19 [3]              492.6   14      38      10      6.90
> 2.5.46 [1]              600.5   13      48      12      8.41
> 2.5.46-mm1 [5]          134.3   58      6       8       1.88
> 2.5.47 [3]              165.9   46      9       9       2.32
> 2.5.47-mm1 [5]          126.3   61      5       8       1.77
> 
> Very nice. Further improvement in 2.5.47-mm1 (note the big change in 2.5.46-47
> is consistent with the preempt addition as mentioned in a previous thread)
> 

Actually, 2.5.47 changed fifo_batch from 32 to 16.  That's what caused
this big shift.

We've increased the kernel build speed by 3.6x while decreasing the
speed at which writes are retired by 5.3x.

It could be argued that this is a net decrease in throughput.  Although
there's clearly a big increase in total CPU utilisation.

It's a tradeoff.  I think this is a better tradeoff than the old one
though.