From: cheloha <cheloha@openbsd.org>
Date: Thu, 22 Jun 2023 16:23:50 +0000 (+0000)
Subject: Revert "clockintr_cpu_init: initialize starting offsets with clockintr_stagger()"
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=76f68ffd642506cd16fc7c53d08c95a06ef6f97b;p=openbsd

Revert "clockintr_cpu_init: initialize starting offsets with clockintr_stagger()"

octeon machines do not increment the global variable "ncpus"
(init_main.c) in the same spot as other platforms, which violates the
KASSERT in clockintr_stagger(), causing a panic.

We need to bring octeon's behavior into alignment with every other
platform before proceeding with this patch.

Reported and debugged by bluhm@.
---

diff --git a/sys/kern/kern_clockintr.c b/sys/kern/kern_clockintr.c
index 22a21996d00..21fad46338b 100644
--- a/sys/kern/kern_clockintr.c
+++ b/sys/kern/kern_clockintr.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: kern_clockintr.c,v 1.24 2023/06/18 23:19:01 cheloha Exp $ */
+/* $OpenBSD: kern_clockintr.c,v 1.25 2023/06/22 16:23:50 cheloha Exp $ */
 /*
  * Copyright (c) 2003 Dale Rahn <drahn@openbsd.org>
  * Copyright (c) 2020 Mark Kettenis <kettenis@openbsd.org>
@@ -107,7 +107,7 @@ clockintr_init(u_int flags)
 void
 clockintr_cpu_init(const struct intrclock *ic)
 {
-	uint64_t multiplier = 0;
+	uint64_t multiplier = 0, offset;
 	struct cpu_info *ci = curcpu();
 	struct clockintr_queue *cq = &ci->ci_queue;
 	int reset_cq_intrclock = 0;
@@ -170,8 +170,8 @@ clockintr_cpu_init(const struct intrclock *ic)
 			clockintr_advance(cq->cq_hardclock, hardclock_period);
 	} else {
 		if (cq->cq_hardclock->cl_expiration == 0) {
-			clockintr_stagger(cq->cq_hardclock, hardclock_period,
-			    multiplier, ncpus);
+			offset = hardclock_period / ncpus * multiplier;
+			cq->cq_hardclock->cl_expiration =  offset;
 		}
 		clockintr_advance(cq->cq_hardclock, hardclock_period);
 	}
@@ -179,16 +179,12 @@ clockintr_cpu_init(const struct intrclock *ic)
 	/*
 	 * We can always advance the statclock and schedclock.
 	 */
-	if (cq->cq_statclock->cl_expiration == 0) {
-		clockintr_stagger(cq->cq_statclock, statclock_avg, multiplier,
-		    ncpus);
-	}
+	offset = statclock_avg / ncpus * multiplier;
+	clockintr_schedule(cq->cq_statclock, offset);
 	clockintr_advance(cq->cq_statclock, statclock_avg);
 	if (schedhz != 0) {
-		if (cq->cq_schedclock->cl_expiration == 0) {
-			clockintr_stagger(cq->cq_schedclock, schedclock_period,
-			    multiplier, ncpus);
-		}
+		offset = schedclock_period / ncpus * multiplier;
+		clockintr_schedule(cq->cq_schedclock, offset);
 		clockintr_advance(cq->cq_schedclock, schedclock_period);
 	}