KSE system scope vs non system scope threads

Jeff Roberson jroberson at chesapeake.net
Sat Nov 29 21:26:50 PST 2003


On Sat, 29 Nov 2003, Christopher M. Sedore wrote:

>
> I have a fairly simple question about KSE threads: In a threaded program using KSE threads, what is the effective difference between a system-scope thread and a non-system-scope thread?  If I understand the KSE architecture correctly, there should not be a significant functional difference.  If my reading lead me to the right conclusion, at the nitty-gritty level, there are multiple KSE groups created with system-scope threads, as I understand it, meaning that the kernel scheduler actually does the scheduling work for system-scope threads, instead of the userland KSE scheduler.
>
> I ask this because I'm observing some behavior that I don't expect.  When running a threaded program with KSE and non-system-scope threads, I see performance degradation in my network traffic when I'm attempting to connect to remote hosts that are down.  Libthr doesn't see this degradation, and KSE with system-scope threads doesn't perform as well as libthr, but is much closer.

Can you describe the threaded application some?  For certain types of
tasks thr is likely to remain faster due to its simplicity.  I'm mostly
just curious to hear what your observations are.

Thanks,
Jeff

>
> If there is a canonical document that describes all this, a pointer would be very welcome.
>
> -Chris
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