Re: realtime scheduling problems with 2.4 linux kernel >= 2.4.10

[Andrea Arcangeli]

On Mon, Jun 03, 2002 at 01:08:17PM -0700, Andrew Morton wrote:
> Mike Kravetz wrote:
> > 
> > ...
> > Seems that this tells people to leave a high priority real-
> > time shell running on the console.  However, if one can not
> > get to the console, then there is no point in leaving a high
> > priority shell running there.  Part of the problem may be
> > in the definition of 'console'.  Different console implementations
> > behave differently.
> > 
> > Is this something we should 'fix'?  I would envision a 'solution'
> > for each console implementation.  OR we could remove the above
> > from the man page. :)
> > 
> 
> keventd is a "process context bottom half handler".  It's designed
> for use by interrupt handlers for handing off awkward, occasional
> things which need process context.  For example, device hotplugging,
> which was the original reason for its introduction.
> 
> So it makes sense to give keventd SCHED_RR policy and maximum
> priority.  Which should fix this problem as well, yes?
> 
> keventd is also being (ab)used for performing disk I/O.
> You know who you are ;)  But even given that, I don't expect
> that elevating its policy&priority will cause any problems.

that's correct, infact that's almost required, kupdate also doesn't have
RT prio and inodes are flushed either by kupdate or keventd.

Andrea