Subject: RE: NetBSD is not Linux
To: None <email@example.com>
From: ali \(Anders Lindgren\) <firstname.lastname@example.org>
Date: 06/12/2001 12:41:51
On Tue, 12 Jun 2001 email@example.com wrote:
[Why process threads are slow]
> because context switching takes time, especially in linux with lots of
With LWPs, you preemptively trap into kernel and switch LWPs. Since
neither method incur a user address-space switch, the kernel overhead
ought to be roughly the same?
I understand completely the difference between userland threads
implementations and kernel implementations; the question is why it is
"known to be inefficient" (as is said around here every time the issue of
kernel threads appear) to switch a struct proc instead of a struct lwp
when both will incur the kernel overhead of preemption and neither will
change the user address-space.
However, I will look into Brian's pointer on the issue -- should be
interesting reading -- and see if there are any answers there.
/ali: Computer Science Major and aspiring cartoonist. :-)
(dept) firstname.lastname@example.org - http://www.ludat.lth.se/~dat94ali
(home) email@example.com - http://h543.sparta.lu.se/
* A4000/040-40/CV3D/Ariadne·AmigaOS·NetBSD·A3000/040-25/Ariadne *