lkml.org 
[lkml]   [2004]   [Nov]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [Fwd: Re: [patch] Real-Time Preemption, -RT-2.6.9-mm1-V0.4]

* Bill Huey <bhuey@lnxw.com> wrote:

> The lock chains aren't that deep in Linux so the algorithmic
> complexity is not going to hit some crazy polynomial time unless
> there's some seriously nasty contention at a certain point in the
> kernel (billions of readers for example against a write aquire). But
> when we start to see things like that under pressure is when we need
> to start shortening the need for that/those lock(s) for that/those
> critical section(s) in question.

also note that in the -U series i removed the true 'read' logic from
semaphores. What we have now are single writers only, plus readers
emulated as a writer plus the ability to self-recurse. ('writers' are
not allowed to self-recurse.) This is quite close to the semantic needs
of Linux rwlocks and rwsems and it simplified both locking, deadlock
detection and PI quite significantly.

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

\
 
 \ /
  Last update: 2005-03-22 14:07    [W:0.121 / U:0.484 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site