From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org,
linux-rt-users <linux-rt-users@vger.kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Carsten Emde <C.Emde@osadl.org>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
John Kacur <jkacur@redhat.com>,
Paul Gortmaker <paul.gortmaker@windriver.com>,
Julia Cartwright <julia@ni.com>,
Daniel Wagner <daniel.wagner@siemens.com>,
tom.zanussi@linux.intel.com, stable-rt@vger.kernel.org,
Mike Galbraith <efault@gmx.de>
Subject: [PATCH RT 21/24] sched: Allow pinned user tasks to be awakened to the CPU they pinned
Date: Fri, 07 Sep 2018 16:59:18 -0400 [thread overview]
Message-ID: <20180907205933.227671780@goodmis.org> (raw)
In-Reply-To: 20180907205857.262840394@goodmis.org
4.14.63-rt41-rc2 stable review patch.
If anyone has any objections, please let me know.
------------------
From: Mike Galbraith <efault@gmx.de>
[ Upstream commit cd4d35ef89948221f7cd1751cee453943967364c ]
Since commit 7af443ee16976 ("sched/core: Require cpu_active() in
select_task_rq(), for user tasks") select_fallback_rq() will BUG() if
the CPU to which a task has pinned itself and pinned becomes
!cpu_active() while it slept.
The task will continue running on the to-be-removed CPU and will remove
itself from the CPU during takedown_cpu() (while cpuhp_pin_lock will be
acquired) and move to another CPU based on its mask after the
migrate_disable() section has been left.
Cc: stable-rt@vger.kernel.org
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
kernel/sched/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index a5ce37b90fca..6e6bd5262f23 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -980,7 +980,7 @@ static inline bool is_cpu_allowed(struct task_struct *p, int cpu)
if (!cpumask_test_cpu(cpu, p->cpus_ptr))
return false;
- if (is_per_cpu_kthread(p))
+ if (is_per_cpu_kthread(p) || __migrate_disabled(p))
return cpu_online(cpu);
return cpu_active(cpu);
--
2.18.0
next prev parent reply other threads:[~2018-09-07 20:59 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-07 20:58 [PATCH RT 00/24] Linux 4.14.63-rt41-rc2 Steven Rostedt
2018-09-07 20:58 ` [PATCH RT 01/24] sched/fair: Fix CFS bandwidth control lockdep DEADLOCK report Steven Rostedt
2018-09-07 20:58 ` [PATCH RT 02/24] locallock: provide {get,put}_locked_ptr() variants Steven Rostedt
2018-09-07 20:59 ` [PATCH RT 03/24] squashfs: make use of local lock in multi_cpu decompressor Steven Rostedt
2018-09-07 20:59 ` [PATCH RT 04/24] PM / suspend: Prevent might sleep splats (updated) Steven Rostedt
2018-09-07 20:59 ` [PATCH RT 05/24] PM / wakeup: Make events_lock a RAW_SPINLOCK Steven Rostedt
2018-09-07 20:59 ` [PATCH RT 06/24] PM / s2idle: Make s2idle_wait_head swait based Steven Rostedt
2018-09-07 20:59 ` [PATCH RT 07/24] seqlock: provide the same ordering semantics as mainline Steven Rostedt
2018-09-07 20:59 ` [PATCH RT 08/24] Revert "x86: UV: raw_spinlock conversion" Steven Rostedt
2018-09-07 20:59 ` [PATCH RT 09/24] Revert "timer: delay waking softirqs from the jiffy tick" Steven Rostedt
2018-09-07 20:59 ` [PATCH RT 10/24] irqchip/gic-v3-its: Make its_lock a raw_spin_lock_t Steven Rostedt
2018-09-07 20:59 ` [PATCH RT 11/24] sched/migrate_disable: fallback to preempt_disable() instead barrier() Steven Rostedt
2018-09-07 20:59 ` [PATCH RT 12/24] irqchip/gic-v3-its: Move ITS ->pend_page allocation into an early CPU up hook Steven Rostedt
2018-09-07 20:59 ` [PATCH RT 13/24] irqchip/gic-v3-its: Move pending table allocation to init time Steven Rostedt
2018-09-07 20:59 ` [PATCH RT 14/24] x86/ioapic: Dont let setaffinity unmask threaded EOI interrupt too early Steven Rostedt
2018-09-07 20:59 ` [PATCH RT 15/24] efi: Allow efi=runtime Steven Rostedt
2018-09-07 20:59 ` [PATCH RT 16/24] efi: Disable runtime services on RT Steven Rostedt
2018-09-07 20:59 ` [PATCH RT 17/24] crypto: cryptd - add a lock instead preempt_disable/local_bh_disable Steven Rostedt
2018-09-07 20:59 ` [PATCH RT 18/24] crypto: scompress - serialize RT percpu scratch buffer access with a local lock Steven Rostedt
2018-09-07 20:59 ` [PATCH RT 19/24] sched/core: Avoid __schedule() being called twice in a row Steven Rostedt
2018-09-07 20:59 ` [PATCH RT 20/24] Revert "arm64/xen: Make XEN depend on !RT" Steven Rostedt
2018-09-07 20:59 ` Steven Rostedt [this message]
2018-09-07 20:59 ` [PATCH RT 23/24] Revert "softirq: keep the softirq pending check RT-only" Steven Rostedt
2018-09-07 20:59 ` [PATCH RT 24/24] Linux 4.14.63-rt41-rc2 Steven Rostedt
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