Module Name: src
Committed By: snj
Date: Thu Jul 14 06:56:03 UTC 2016
Modified Files:
src/sys/kern [netbsd-6]: kern_softint.c
Log Message:
Pull up following revision(s) (requested by knakahara in ticket #1356):
sys/kern/kern_softint.c: revision 1.42
fix the following softint parallel operation problem.
(0) softint handler "handler A" is established
(1) CPU#X does softint_schedule() for "handler A"
- the softhand_t is set SOFTINT_PENDING flag
- the softhand_t is NOT set SOFTINT_ACTIVE flag yet
(2) CPU#X begins other H/W interrupt processing
(3) CPU#Y does softint_disestablish() for "handler A"
- waits until softhand_t's SOFTINT_ACTIVE of all CPUs is clear
- the softhand_t is set not SOFTINT_ACTIVE but SOFTINT_PENDING,
so CPU#Y does not wait
- unset the function of "handler A"
(4) CPU#X does softint_execute()
- the function of "handler A" is already clear, so panic
To generate a diff of this commit:
cvs rdiff -u -r1.38.8.1 -r1.38.8.2 src/sys/kern/kern_softint.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_softint.c
diff -u src/sys/kern/kern_softint.c:1.38.8.1 src/sys/kern/kern_softint.c:1.38.8.2
--- src/sys/kern/kern_softint.c:1.38.8.1 Fri Feb 8 19:32:07 2013
+++ src/sys/kern/kern_softint.c Thu Jul 14 06:56:03 2016
@@ -1,4 +1,4 @@
-/* $NetBSD: kern_softint.c,v 1.38.8.1 2013/02/08 19:32:07 riz Exp $ */
+/* $NetBSD: kern_softint.c,v 1.38.8.2 2016/07/14 06:56:03 snj Exp $ */
/*-
* Copyright (c) 2007, 2008 The NetBSD Foundation, Inc.
@@ -176,7 +176,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_softint.c,v 1.38.8.1 2013/02/08 19:32:07 riz Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_softint.c,v 1.38.8.2 2016/07/14 06:56:03 snj Exp $");
#include <sys/param.h>
#include <sys/proc.h>
@@ -424,8 +424,8 @@ softint_disestablish(void *arg)
KASSERT(sh->sh_func != NULL);
flags |= sh->sh_flags;
}
- /* Inactive on all CPUs? */
- if ((flags & SOFTINT_ACTIVE) == 0) {
+ /* Neither pending nor active on all CPUs? */
+ if ((flags & (SOFTINT_PENDING | SOFTINT_ACTIVE)) == 0) {
break;
}
/* Oops, still active. Wait for it to clear. */
