linux-kernel - [PATCH 1/2] Revert "cpu hotplug: adjust root-domain->online span in response to hotplug

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 10 Mar 2008 16:52:41 -0400
From:	Gregory Haskins <ghaskins@...ell.com>
To:	unlisted-recipients:; (no To-header on input)
Cc:	linux-kernel@...r.kernel.org, ghaskins@...ell.com,
	Gregory Haskins <ghaskins@...ell.com>
Subject: [PATCH 1/2] Revert "cpu hotplug: adjust root-domain->online span in
	response to hotplug

event"

This reverts commit 393d94d98b19089ec172566e23557997931b137e.

I submitted 393d94d98b1 to -mm and sched-devel, and then quickly realized
it was flawed.  However, the patch was already "in flight" and made it
to Linus' tree and is in .25-rc5.  So this patch reverts the
original/flawed fix, and the patch that follows has the updated version.

Signed-off-by: Gregory Haskins <ghaskins@...ell.com>
Cc: Gautham R Shenoy <ego@...ibm.com>
Cc: "Siddha, Suresh B" <suresh.b.siddha@...el.com>
Cc: Ingo Molnar <mingo@...e.hu>
Cc: "Rafael J. Wysocki" <rjw@...k.pl>
Cc: Andrew Morton <akpm@...ux-foundation.org>
---

 kernel/sched.c |   18 +++++++++++-------
 1 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/kernel/sched.c b/kernel/sched.c
index b02e4fc..52b9867 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -5813,13 +5813,6 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
 		/* Must be high prio: stop_machine expects to yield to it. */
 		rq = task_rq_lock(p, &flags);
 		__setscheduler(rq, p, SCHED_FIFO, MAX_RT_PRIO-1);
-
-		/* Update our root-domain */
-		if (rq->rd) {
-			BUG_ON(!cpu_isset(cpu, rq->rd->span));
-			cpu_set(cpu, rq->rd->online);
-		}
-
 		task_rq_unlock(rq, &flags);
 		cpu_rq(cpu)->migration_thread = p;
 		break;
@@ -5828,6 +5821,15 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
 	case CPU_ONLINE_FROZEN:
 		/* Strictly unnecessary, as first user will wake it. */
 		wake_up_process(cpu_rq(cpu)->migration_thread);
+
+		/* Update our root-domain */
+		rq = cpu_rq(cpu);
+		spin_lock_irqsave(&rq->lock, flags);
+		if (rq->rd) {
+			BUG_ON(!cpu_isset(cpu, rq->rd->span));
+			cpu_set(cpu, rq->rd->online);
+		}
+		spin_unlock_irqrestore(&rq->lock, flags);
 		break;
 
 #ifdef CONFIG_HOTPLUG_CPU
@@ -6103,6 +6105,8 @@ static void rq_attach_root(struct rq *rq, struct root_domain *rd)
 	rq->rd = rd;
 
 	cpu_set(rq->cpu, rd->span);
+	if (cpu_isset(rq->cpu, cpu_online_map))
+		cpu_set(rq->cpu, rd->online);
 
 	for (class = sched_class_highest; class; class = class->next) {
 		if (class->join_domain)

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/