Re: [Caml-list] Re: OCaml is broken

[Erik Rigtorp <erik@rigtorp.com>]

On Tue, Dec 22, 2009 at 14:27, Gerd Stolpmann <gerd@gerd-stolpmann.de> wrote:
>
> Am Dienstag, den 22.12.2009, 13:04 +0100 schrieb Erik Rigtorp:
>> On Mon, Dec 21, 2009 at 23:50, Erik Rigtorp <erik@rigtorp.com> wrote:
>> > Some IPC Benchmarks, Solaris 10 on a quad core Intel Core2 Duo. The
>> > benchmarks are running on a cpuset with 1 core. I measure the time
>> > from sending in one process until the other process receives the
>> > message. So a context switch and the message passing is included in
>> > the measurements.
>> >
>> > Max/Min/Avg
>> > * Pipes: 28205/5973/6259
>> > * Unix domain sockets: 44256/7748/8153
>> > * SYSv message queues: 19197/5895/6173
>> > * Posix message queues: 37399/10965/11303
>> > * TCP on loopback: 29017/7471/7885
>> >
>> > So the latency is roughly 10µs for all these solutions. That latency
>> > is pretty high and would be several times the processing time of the
>> > message itself.
>>
>> Some more benchmarks:
>>
>> Max/Min/Avg
>> * Spinlocking shm: 50897/403/761  (This one utilizes multiple cores,
>> since one core is just burning while waiting for data)
>> * Pthreads mutex shm: 27582/5246/6577
>>
>> Forgot to say that all measurements are in nanoseconds.
>
> That's for communication between processes, right? How would the picture
> be different (especially comparing the latter two) if you do message
> passing between threads? If I remember correctly, threads are more
> light-weight in Solaris than processes. That could also affect context
> switching times, and scheduler decisions.

With a system supporting green threads/tasklets/erlang processes over
multiple cores you can have 1µs message passing latencies without busy
waiting. I'll checkout the thread message passing too, but probably
not until after new years.

> Do you have source code? I could also run in on Linux, for comparison.

I'll have that approved by my company first. It would actually be
interesting to create a open source multiplatform IPC message passing
benchmark.

Erik