Re: [patch 00/13] Syslets, "Threadlets", generic AIO support, v3

Evgeniy Polyakov
2007-02-22T11:37:05Z

Hi Ingo, developers.

On Thu, Feb 22, 2007 at 08:40:44AM +0100, Ingo Molnar (mingo@elte.hu) wrote:
> Syslets/threadlets on the other hand, once the core is implemented, have
> near zero ongoing maintainance cost (compared to KAIO pushed into every
> IO subsystem) and cover all IO disciplines and API variants immediately,
> and they are as perfectly asynchronous as it gets.
>
> So all in one, i used to think that AIO state-machines have a long-term
> place within the kernel, but with syslets i think i've proven myself
> embarrasingly wrong =B-)

Hmm...
Try to have a network web server with huge load made on top of
syslets/threadlets.

It is not a TUX anymore - you had 1024 threads, and all of them will be
consumed by tcp_sendmsg() for slow clients - rescheduling will kill a
machine.

My tests show that with 4k connections per second (8k concurrency) more
than 20k connections of 80k total block in tcp_sendmsg() over gigabit
lan between quite fast machines.

Or threadlet/syslet AIO should not be used with networking too?

> Ingo

--
Evgeniy Polyakov