Re: 2.4.18pre4aa1

[rwhron@earthlink.net]

>   [snip results:  -aa twice as fast as -rmap for dbench,
>                   -rmap twice as fast as -aa for tiobench]

Look closely at all the numbers:

dbench 64 128 192 on ext completed in 4500 seconds on 2.4.18pre4aa1
dbench 64 128 192 on ext completed in 12471 seconds on 2.4.17rmap12a

2.4.18pre4aa1 completed the three dbenches 277% faster.

For tiobench:

Tiobench is interesting because it has the CPU% column.  I mentioned 
sequential reads because it's a bench where 2.4.17rmap12a was faster.  
Someone else might say 2.4.18pre4aa1 was 271% faster at random reads.  
Let's analyze CPU efficiency where threads = 1:

               Num     Seq Read     Rand Read      Seq Write   Rand Write
               Thr    Rate (CPU%)  Rate (CPU%)    Rate (CPU%)  Rate (CPU%)
               ---  -------------  -----------  -------------  -----------
2.4.17rmap12a    1   22.85  32.2%   1.15  2.2%   13.10  83.5%   0.71  1.6%
2.4.18pre4aa1    1   11.23  21.3%   3.12  4.8%   11.92  66.1%   0.66  1.3%


Sequential Read CPU Efficiency
2.4.18pre4aa1   11.23 / .213 = 52.723
2.4.17rmap12a   22.85 / .322 = 70.962
2.4.17rmap12a was 35% more CPU efficent.

Random Read CPU Efficiency
2.4.18pre4aa1   3.12 / .048 = 65.000
2.4.17rmap12a   1.15 / .022 = 52.272
2.4.18pre4aa1 was 24% more CPU efficient.

Sequential Write CPU Efficiency
2.4.18pre4aa1   11.92 / .661 = 18.033
2.4.17rmap12a   13.10 / .835 = 15.688
2.4.18pre4aa1 was 15% more CPU efficient.

Random Write CPU Efficiency
2.4.18pre4aa1   .066 / .013 = 50.767
2.4.17rmap12a   .071 / .016 = 44.375
2.4.18pre4aa1 was 14% more CPU efficient.

> It would be interesting to see the dbench dots from both
> -aa and -rmap ;)

All the dots are at:
http://home.earthlink.net/~rwhron/kernel/dots/

-- 
Randy Hron