libthr and 1:1 threading.

[Terry Lambert]

Sheldon Hearn wrote:
> On (2003/04/02 07:38), Terry Lambert wrote:
> > Is the disk I/O really that big of an issue?  All writes will
> > be on underlying non-blocking descriptors; I guess you are
> > saying that the interleaved I/O is more important, further
> > down the system call interface than the top, and this becomes
> > an issue?
> 
> Dude, you should really try this stuff for yourself before naysaying
> performance improvements on principle.  It's actually quite impressive
> for desktop users (at least).

I have.  I can't tell if it's the scheduler quantums or the
concurrency from the threads.

I'm going to have to specifically write code to find out, and
it may take me a while to do it; I have to figure out a way
to put the user space stalls back for descriptor accesses, so
the tests run on an equal footing.

Right now, I have to decide whether it's worth the hassle of
combining the libc_r and libthr code to do that, or if I should
just drop it, and let you guys turn FreeBSD's threads into Linux.

PS: My gut tells me it's not the concurrency; the resolver is
the bottleneck for things like Mozilla (IMO), and it still has
to stall concurrency.

PPS: I'll get back to you after I size the job, and decide.

-- Terry