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

Ingo Molnar
2007-02-23T12:26:48Z

* Michael K. Edwards <medwards.linux@gmail.com> wrote:

> On 2/22/07, Ingo Molnar <mingo@elte.hu> wrote:

> > maybe it will, maybe it wont. Lets try? There is no true difference
> > between having a 'request structure' that represents the current
> > state of the HTTP connection plus a statemachine that moves that
> > request between various queues, and a 'kernel stack' that goes in
> > and out of runnable state and carries its processing state in its
> > stack - other than the amount of RAM they take. (the kernel stack is
> > 4K at a minimum - so with a million outstanding requests they would
> > use up 4 GB of RAM. With 20k outstanding requests it's 80 MB of RAM
> > - that's acceptable.)
>
> This is a fundamental misconception. [...]

> The scheduler, on the other hand, has to blow and reload all of the
> hidden state associated with force-loading the PC and wherever your
> architecture keeps its TLS (maybe not the whole TLB, but not nothing,
> either). [...]

please read up a bit more about how the Linux scheduler works. Maybe
even read the code if in doubt? In any case, please direct kernel newbie
questions to http://kernelnewbies.org/, not linux-kernel@vger.kernel.org.

Ingo