Re: [BENCHMARK] 2.5.68 and 2.5.68-mm2

[rwhron@earthlink.net]

>> The autoconf-2.53 make/make check is a fork test.   2.5.68
>> is about 13% faster here.

> I wonder why.  Which fs was it?

That was on ext2.  There isn't much i/o on autoconf "make check".
It's a lot of small perl scripts, m4 and gcc on tiny files.

>> On the AIM7 database test, -mm2 was about 18% faster and

> iirc, AIM7 is dominated by lots of O_SYNC writes.  I'd have expected the
> anticipatory scheduler to do worse.  Odd.  Which fs was it?

That was ext2 too.

> tiobench will create a bunch of processes, each growing a large file, all
> in the same directory.  

> The benchmark is hitting a pathologoical case.  Yeah, it's a problem, but
> it's not as bad as tiobench indicates.

Oracle doing reads/writes to preallocated, contiguous files is more 
important than tiobench.  Oracle datafiles are typically created
sequentially, which wouldn't exercise the pathology.

I pay more attention the OSDL-DBT-3 and "Winmark I" numbers than 
the i/o stuff I run.  (I look at my numbers more, but care about
theirs more).

What about the behavior where CPU utilization goes down as thread
count goes up?  Is she just i/o bound?

Sequential Reads ext2
	       Num                 
Kernel         Thr   Rate   (CPU%)  
----------     ---   -----  ------
2.5.68           8   36.65  18.04%  
2.5.68-mm2       8   23.96  11.15%  

2.5.68         256   34.10  16.88%  
2.5.68-mm2     256   18.84   8.96%  

-- 
Randy Hron
http://home.earthlink.net/~rwhron/kernel/bigbox.html