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Code Issues Releases Activity

priority comparison in maybe_resched() didn't work properly if current

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and chk process were on different scheduler queues.  Fixed.
This commit is contained in:
Matthew Dillon 1998-08-26 05:27:42 +00:00
parent 842d977707
commit 8e519d1f35
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=38551
1 changed files with 13 additions and 6 deletions
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19
sys/kern/kern_synch.c
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@ -36,7 +36,7 @@
* SUCH DAMAGE.
*
* @(#)kern_synch.c 8.9 (Berkeley) 5/19/95
* $Id: kern_synch.c,v 1.60 1998/07/11 13:06:41 bde Exp $
* $Id: kern_synch.c,v 1.61 1998/07/15 02:32:10 bde Exp $
*/
#include "opt_ktrace.h"
@ -107,14 +107,21 @@ static void maybe_resched(struct proc *chk)
{
struct proc *p = curproc; /* XXX */
/* If the current scheduler is the idle scheduler or
* the priority of the new one is higher then reschedule.
/*
* Compare priorities if the new process is on the same scheduler,
* otherwise the one on the more realtimeish scheduler wins.
*
* XXX idle scheduler still broken because proccess stays on idle
* scheduler during waits (such as when getting FS locks). If a
* standard process becomes runaway cpu-bound, the system can lockup
* due to idle-scheduler processes in wakeup never getting any cpu.
*/
if (p == 0 ||
RTP_PRIO_BASE(p->p_rtprio.type) == RTP_PRIO_IDLE ||
(chk->p_priority < curpriority &&
RTP_PRIO_BASE(p->p_rtprio.type) == RTP_PRIO_BASE(chk->p_rtprio.type)) )
(chk->p_priority < curpriority && RTP_PRIO_BASE(p->p_rtprio.type) == RTP_PRIO_BASE(chk->p_rtprio.type)) ||
RTP_PRIO_BASE(chk->p_rtprio.type) < RTP_PRIO_BASE(p->p_rtprio.type)
) {
need_resched();
}
}
#define ROUNDROBIN_INTERVAL (hz / quantum)