On 2009-03-12, Michael Schnell <mschn...@lumino.de> wrote:
>
>> it doesn't even have NPTL support.  That means that scheduling
>> of threads is being done by user-space code.

> I suppose that you are wrong with that conclusion.

Could be.  I'm not sure which posix implementation is used on
the NIOS.  Some implementations did do everything in
user-space, and I thought I read that the NIOS port used one of
those.

> If the thread scheduling in fact would be done completely in
> user-space it would be _really_ fast, as the OS would not be
> involved.

I don't follow that argument, but it's a moot point if NIOS is
using LinuxThreads.

> But on the contrary with "Linux Treads", each thread is a
> complete process and inter-thread communication is not better
> than inter-process communication (e.g. due to lack of TLS and
> FUTEX).

Agreed.  I was thinking for some reason that on NIOS the
pre-LinuxThreads library was being used.  If NIOS is using
LinuxThreads, then something other than user-space scheduling
is the source of the large latencies.

> But happily it seems that NIOS uCLinux will get MMU support
> quite soon

For large enough values of "quite soon". :/

IIRC, the MMU support has been coming "soon" for almost two
years.  I started working with NIOS about 4-5 years ago, and
have had to completely recalibrate what "soon" means when
Altera is involved.  I've also had do develop new definitions
for what "working" and "usable" mean.

> and we will be able to take advantage from these goodies :).

Good luck.

> I did not take any look into that but as the Microblaze can be
> compiled with an MMU even longer than the NIOS, maybe it's
> Linux can already do all that.

-- 
Grant Edwards                   grante             Yow! Now I'm concentrating
                                  at               on a specific tank battle
                               visi.com            toward the end of World
                                                   War II!

_______________________________________________
uClinux-dev mailing list
uClinux-dev@uclinux.org
http://mailman.uclinux.org/mailman/listinfo/uclinux-dev
This message was resent by uclinux-dev@uclinux.org
To unsubscribe see:
http://mailman.uclinux.org/mailman/options/uclinux-dev

Reply via email to