lkml.org 
[lkml]   [1999]   [Jul]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: kernel thread support - LWP's
Date
Donald Sharp wrote:
>
> I have never understood this arguement. With LWP's you have to spend
> time in 2 schedulers: The kernel's and the Thread libraries. I guess
> they might be able to claim that the thread libraries scheduler is much
> much faster than the kernel's scheduler, so you end up with a bonus.

Splitting an N-job scheduling task into an M-job low-level scheduling
tasks and a single N/M-job high-level scheduling task is a win.
In theory.

In practice it depends. There's a list traversal in schedule() that would
speed up if you have a whole bunch of threads and you split the scheduling
into two levels, but it's probably going to take a lot of runnable tasks
before this loop dominates the other overhead, and at that point a bit of
overhead in schedule() is probably the least of your worries.

--
............................................................................
Peter Desnoyers
162 Pleasant St. (617) 661-1979 pjd@fred.cambridge.ma.us
Cambridge, Mass. 02139 (978) 461-0402 (work) pjd@giga-net.com

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:53    [W:0.083 / U:0.808 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site