lkml.org 
[lkml]   [2007]   [Aug]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: allow non root users to set io priority "idle" ?
On Wed, Aug 08, 2007 at 01:51:32PM +0400, Sheplyakov Alexei wrote:
> On Mon, Aug 06, 2007 at 01:11:01PM +0200, Andi Kleen wrote:
>
> > Very low priority can starve others when it holds some kernel resource
> > needed by another task.
>
> Nevertheless ordinary users are permitted to lower priority ([re]nice)

Low priority as allowed by renice is ok -- the resource holder will
run eventually and the system make progress.

> I don't quite understand. There are a lot of other ways to starve such
> high-priority process:
> 1. renice the low-priority process

That requires user action.

e.g. if you google a bit you can find a famous story where the NASA
had to do that remotely to solve a PI problem on one of the Mars rovers. But I'm
sure they weren't very pleased about it. And not everybody has a JPL
control room to patch things up in the backhand.

> 2. send it a signal
> 3. ptrace it

Only root can do these.

-Andi

-
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: 2007-08-08 12:23    [from the cache]
©2003-2011 Jasper Spaans