linux-mips
[Top] [All Lists]

Re: [pathch] kernel/sched.c bogon?

To: "Jun Sun" <jsun@mvista.com>
Subject: Re: [pathch] kernel/sched.c bogon?
From: "Kip Walker" <kwalker@broadcom.com>
Date: Thu, 24 Apr 2003 10:03:05 -0700
Cc: "Ralf Baechle" <ralf@linux-mips.org>, linux-mips@linux-mips.org
Organization: Broadcom Corp. BPBU
Original-recipient: rfc822;linux-mips@linux-mips.org
References: <3E67EF64.152CFC6C@broadcom.com> <20030306174001.K26071@mvista.com> <20030310135531.B2206@linux-mips.org> <20030310095907.U26071@mvista.com>
Sender: linux-mips-bounce@linux-mips.org
Jun Sun wrote:
> 
> On Mon, Mar 10, 2003 at 01:55:31PM +0100, Ralf Baechle wrote:
> > On Thu, Mar 06, 2003 at 05:40:01PM -0800, Jun Sun wrote:
> >
> > > I reported this bug last May.  Apparently it is still not
> > > taken up-stream.   Ralf, why don't we fix it here and push
> > > it up from you?
> > >
> > > BTW, this bug actually has effect on real-time performance under
> > > preemptible kernel.
> >
> > < = 2.4.x preemptible kernel is OPP.
> >
> > >  It can delay the execution of the highest
> > > priority real-time process from execution up to 1 jiffy.
> >
> > Quite a number of users get_cycles() in the kernel assume it to return a
> > 64-bit number.  I guess we'll have to fake a 64-bit counter in software ...
> >
> 
> Whether we fake 64-bit or not, oldest_idle is declared as cycles_t.
> So comparing it with (cycles_t)-1 should be always be correct.  And it
> actually makes a correct C program. :-)
> 
> I don't see any possible reason for rejecting the change.  My previous
> report is probably just lost in the noise.

And once again, the patch hasn't made it in.  Can we either apply it get
a good reason not to?

Kip


<Prev in Thread] Current Thread [Next in Thread>