lkml.org 
[lkml]   [2003]   [Mar]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] limits on SCHED_FIFO tasks
Andrew Morton wrote:
> george anzinger <george@mvista.com> wrote:
>
>>If the issue is regaining control after some RT task goes into a loop,
>>the way this is usually done is to keep a session around with a higher
>>priority. Using this concept, one might provide tools that, from
>>userland, insure that such a session exists prior to launching the
>>"suspect" code. I fail to see the need for this sort of code in the
>>kernel.
>
>
> That works, until your shell calls ext3_mark_inode_dirty(), which blocks on
> kjournald activity. kjournald is SCHED_OTHER, and never runs...
>
That is classic priority inversion. It would be "nice" to find a fix
for that :) I think that the proposed action should not be triggered
until there is some "notice" that something is wrong. I suppose it
could be a watchdog timer of some sort. Still, if the priority
inversion issue were solved, all the rest could be done in user land.

>
>

--
George Anzinger george@mvista.com
High-res-timers: http://sourceforge.net/projects/high-res-timers/
Preemption patch: http://www.kernel.org/pub/linux/kernel/people/rml

-
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 13:34    [W:0.039 / U:2.436 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site