Module Name: src
Committed By: mlelstv
Date: Fri Nov 30 15:05:35 UTC 2018
Modified Files:
src/sys/kern: kern_synch.c
Log Message:
The SHOULDYIELD flag doesn't indicate that other LWPs could run but only
that the current LWP was seen on two consecutive scheduler intervals.
There are currently at least 3 cases for calling preempt().
- always call preempt()
- check the SHOULDYIELD flag
- check the real ci_want_resched
So the forced check for SHOULDYIELD changed the scheduler timing. Revert
it for now.
To generate a diff of this commit:
cvs rdiff -u -r1.321 -r1.322 src/sys/kern/kern_synch.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/kern/kern_synch.c
diff -u src/sys/kern/kern_synch.c:1.321 src/sys/kern/kern_synch.c:1.322
--- src/sys/kern/kern_synch.c:1.321 Wed Nov 28 19:46:22 2018
+++ src/sys/kern/kern_synch.c Fri Nov 30 15:05:35 2018
@@ -1,4 +1,4 @@
-/* $NetBSD: kern_synch.c,v 1.321 2018/11/28 19:46:22 mlelstv Exp $ */
+/* $NetBSD: kern_synch.c,v 1.322 2018/11/30 15:05:35 mlelstv Exp $ */
/*-
* Copyright (c) 1999, 2000, 2004, 2006, 2007, 2008, 2009
@@ -69,7 +69,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_synch.c,v 1.321 2018/11/28 19:46:22 mlelstv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_synch.c,v 1.322 2018/11/30 15:05:35 mlelstv Exp $");
#include "opt_kstack.h"
#include "opt_dtrace.h"
@@ -286,10 +286,6 @@ preempt(void)
{
struct lwp *l = curlwp;
- /* check if the scheduler has another LWP to run */
- if ((l->l_cpu->ci_schedstate.spc_flags & SPCF_SHOULDYIELD) == 0)
- return;
-
KERNEL_UNLOCK_ALL(l, &l->l_biglocks);
lwp_lock(l);
KASSERT(lwp_locked(l, l->l_cpu->ci_schedstate.spc_lwplock));
