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From: zanussi@kernel.org
To: LKML <linux-kernel@vger.kernel.org>,
	linux-rt-users <linux-rt-users@vger.kernel.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Carsten Emde <C.Emde@osadl.org>, John Kacur <jkacur@redhat.com>,
	Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
	Daniel Wagner <wagi@monom.org>, Tom Zanussi <zanussi@kernel.org>
Subject: [PATCH RT 19/23] sched/core: migrate_enable() must access takedown_cpu_task on !HOTPLUG_CPU
Date: Thu, 27 Feb 2020 08:33:30 -0600	[thread overview]
Message-ID: <fc234fb7e45164ddd61e0dbf1f8455a8252994c3.1582814004.git.zanussi@kernel.org> (raw)
In-Reply-To: <cover.1582814004.git.zanussi@kernel.org>
In-Reply-To: <cover.1582814004.git.zanussi@kernel.org>

From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

v4.14.170-rt75-rc2 stable review patch.
If anyone has any objections, please let me know.

-----------


[ Upstream commit a61d1977f692e46bad99a100f264981ba08cb4bd ]

The variable takedown_cpu_task is never declared/used on !HOTPLUG_CPU
except for migrate_enable(). This leads to a link error.

Don't use takedown_cpu_task in !HOTPLUG_CPU.

Reported-by: Dick Hollenbeck <dick@softplc.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
---
 kernel/cpu.c        | 2 ++
 kernel/sched/core.c | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/kernel/cpu.c b/kernel/cpu.c
index 17b1ed41bc06..861712ebb81d 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -858,7 +858,9 @@ static int take_cpu_down(void *_param)
 	return 0;
 }
 
+#ifdef CONFIG_PREEMPT_RT_BASE
 struct task_struct *takedown_cpu_task;
+#endif
 
 static int takedown_cpu(unsigned int cpu)
 {
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index ceddb1e27caf..e10e3956bb29 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -6987,9 +6987,11 @@ void migrate_enable(void)
 
 	p->migrate_disable = 0;
 	rq->nr_pinned--;
+#ifdef CONFIG_HOTPLUG_CPU
 	if (rq->nr_pinned == 0 && unlikely(!cpu_active(cpu)) &&
 	    takedown_cpu_task)
 		wake_up_process(takedown_cpu_task);
+#endif
 
 	if (!p->migrate_disable_scheduled)
 		goto out;
-- 
2.14.1


  parent reply	other threads:[~2020-02-27 14:34 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-27 14:33 [PATCH RT 00/23] Linux v4.14.170-rt75-rc2 zanussi
2020-02-27 14:33 ` [PATCH RT 01/23] Fix wrong-variable use in irq_set_affinity_notifier zanussi
2020-02-27 14:33 ` [PATCH RT 02/23] i2c: exynos5: Remove IRQF_ONESHOT zanussi
2020-02-27 14:33 ` [PATCH RT 03/23] i2c: hix5hd2: " zanussi
2020-02-27 14:33 ` [PATCH RT 04/23] x86: preempt: Check preemption level before looking at lazy-preempt zanussi
2020-02-27 14:33 ` [PATCH RT 05/23] sched: migrate_dis/enable: Use sleeping_lock…() to annotate sleeping points zanussi
2020-02-27 14:33 ` [PATCH RT 06/23] sched: __set_cpus_allowed_ptr: Check cpus_mask, not cpus_ptr zanussi
2020-02-27 14:33 ` [PATCH RT 07/23] sched: Remove dead __migrate_disabled() check zanussi
2020-02-27 14:33 ` [PATCH RT 08/23] sched: migrate disable: Protect cpus_ptr with lock zanussi
2020-02-27 14:33 ` [PATCH RT 09/23] lib/smp_processor_id: Don't use cpumask_equal() zanussi
2020-02-27 14:33 ` [PATCH RT 10/23] futex: Make the futex_hash_bucket spinlock_t again and bring back its old state zanussi
2020-02-27 14:33 ` [PATCH RT 11/23] locking/rtmutex: Clean ->pi_blocked_on in the error case zanussi
2020-02-27 14:33 ` [PATCH RT 12/23] lib/ubsan: Don't seralize UBSAN report zanussi
2020-02-27 14:33 ` [PATCH RT 13/23] kmemleak: Change the lock of kmemleak_object to raw_spinlock_t zanussi
2020-02-27 14:33 ` [PATCH RT 14/23] Revert "ARM: Initialize split page table locks for vector page" zanussi
2020-02-27 14:33 ` [PATCH RT 15/23] locking: Make spinlock_t and rwlock_t a RCU section on RT zanussi
2020-02-27 14:33 ` [PATCH RT 16/23] sched: migrate_enable: Use select_fallback_rq() zanussi
2020-02-27 14:33 ` [PATCH RT 17/23] sched: Lazy migrate_disable processing zanussi
2020-02-27 14:33 ` [PATCH RT 18/23] sched: migrate_enable: Use stop_one_cpu_nowait() zanussi
2020-02-27 14:33 ` zanussi [this message]
2020-02-27 14:33 ` [PATCH RT 20/23] lib/smp_processor_id: Adjust check_preemption_disabled() zanussi
2020-02-27 14:33 ` [PATCH RT 21/23] sched: migrate_enable: Busy loop until the migration request is completed zanussi
2020-03-03 19:56   ` Scott Wood
2020-03-03 20:39     ` Tom Zanussi
2020-03-03 21:19       ` Scott Wood
2020-03-03 21:54         ` Steven Rostedt
2020-03-05 13:38   ` David Laight
2020-03-05 17:58     ` Tom Zanussi
2020-02-27 14:33 ` [PATCH RT 22/23] sched/deadline: Ensure inactive_timer runs in hardirq context zanussi
2020-02-27 14:33 ` [PATCH RT 23/23] Linux 4.14.170-rt75-rc2 zanussi

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