Re: Mainline kernel OLTP performance update

On Saturday 17 January 2009 05:11:02 Rick Jones wrote:

Nick Piggin wrote:

quoted

OK, I have these numbers to show I'm not completely off my rocker to
suggest we merge SLQB :) Given these results, how about I ask to merge
SLQB as default in linux-next, then if nothing catastrophic happens,
merge it upstream in the next merge window, then a couple of releases
after that, given some time to test and tweak SLQB, then we plan to bite
the bullet and emerge with just one main slab allocator (plus SLOB).


System is a 2socket, 4 core AMD.

Not exactly a large system :)  Barely NUMA even with just two sockets.

You're right ;)

But at least it is exercising the NUMA paths in the allocator, and
represents a pretty common size of system...

I can run some tests on bigger systems at SUSE, but it is not always
easy to set up "real" meaningful workloads on them or configure
significant IO for them.

quoted

Netperf UDP unidirectional send test (10 runs, higher better):

Server and client bound to same CPU
SLAB AVG=60.111 STD=1.59382
SLQB AVG=60.167 STD=0.685347
SLUB AVG=58.277 STD=0.788328

Server and client bound to same socket, different CPUs
SLAB AVG=85.938 STD=0.875794
SLQB AVG=93.662 STD=2.07434
SLUB AVG=81.983 STD=0.864362

Server and client bound to different sockets
SLAB AVG=78.801 STD=1.44118
SLQB AVG=78.269 STD=1.10457
SLUB AVG=71.334 STD=1.16809

 > ...

quoted

I haven't done any non-local network tests. Networking is the one of the
subsystems most heavily dependent on slab performance, so if anybody
cares to run their favourite tests, that would be really helpful.

I'm guessing, but then are these Mbit/s figures? Would that be the sending
throughput or the receiving throughput?

Yes, Mbit/s. They were... hmm, sending throughput I think, but each pair
of numbers seemed to be identical IIRC?

I love to see netperf used, but why UDP and loopback?

No really good reason. I guess I was hoping to keep other variables as
small as possible. But I guess a real remote test would be a lot more
realistic as a networking test. Hmm, but I could probably set up a test
over a simple GbE link here.  I'll try that.

Also, how about the
service demands?

Well, over loopback and using CPU binding, I was hoping it wouldn't
change much... but I see netperf does some measurements for you. I
will consider those in future too.

BTW. is it possible to do parallel netperf tests?