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Date: Thu, 6 Mar 2003 17:40:01 -0800
From: Jun Sun <jsun@mvista.com>
To: Kip Walker <kwalker@broadcom.com>
Cc: linux-mips@linux-mips.org, jsun@mvista.com
Subject: Re: [pathch] kernel/sched.c bogon?
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In-Reply-To: <3E67EF64.152CFC6C@broadcom.com>; from kwalker@broadcom.com on Thu, Mar 06, 2003 at 05:01:24PM -0800
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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.  It can delay the execution of the highest
priority real-time process from execution up to 1 jiffy.

Jun

On Thu, Mar 06, 2003 at 05:01:24PM -0800, Kip Walker wrote:
> 
> The comparisons of oldest_idle below trigger compiler warnings and
> should probably be safely type-cast:
> 
> Kip
> 
> Index: kernel/sched.c
> ===================================================================
> RCS file: /home/cvs/linux/kernel/sched.c,v
> retrieving revision 1.64.2.6
> diff -u -r1.64.2.6 sched.c
> --- kernel/sched.c      25 Feb 2003 22:03:13 -0000      1.64.2.6
> +++ kernel/sched.c      7 Mar 2003 00:57:35 -0000
> @@ -282,7 +282,7 @@
>                                 target_tsk = tsk;
>                         }
>                 } else {
> -                       if (oldest_idle == -1ULL) {
> +                       if (oldest_idle == (cycles_t) -1) {
>                                 int prio = preemption_goodness(tsk, p,
> cpu);
>  
>                                 if (prio > max_prio) {
> @@ -294,7 +294,7 @@
>         }
>         tsk = target_tsk;
>         if (tsk) {
> -               if (oldest_idle != -1ULL) {
> +               if (oldest_idle != (cycles_t) -1) {
>                         best_cpu = tsk->processor;
>                         goto send_now_idle;
>                 }
> 
>