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>, Julia Cartwright <julia@ni.com>,
Daniel Wagner <wagi@monom.org>, Tom Zanussi <zanussi@kernel.org>,
Scott Wood <swood@redhat.com>
Subject: [PATCH RT 22/30] sched: migrate_enable: Use select_fallback_rq()
Date: Thu, 23 Jan 2020 15:39:52 -0500 [thread overview]
Message-ID: <20200123203945.463187246@goodmis.org> (raw)
In-Reply-To: 20200123203930.646725253@goodmis.org
4.19.94-rt39-rc2 stable review patch.
If anyone has any objections, please let me know.
------------------
From: Scott Wood <swood@redhat.com>
[ Upstream commit adfa969d4cfcc995a9d866020124e50f1827d2d1 ]
migrate_enable() currently open-codes a variant of select_fallback_rq().
However, it does not have the "No more Mr. Nice Guy" fallback and thus
it will pass an invalid CPU to the migration thread if cpus_mask only
contains a CPU that is !active.
Signed-off-by: Scott Wood <swood@redhat.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/sched/core.c | 25 ++++++++++---------------
1 file changed, 10 insertions(+), 15 deletions(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index d9a3f88508ee..6fd3f7b4d7d8 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -7335,6 +7335,7 @@ void migrate_enable(void)
if (p->migrate_disable_update) {
struct rq *rq;
struct rq_flags rf;
+ int cpu = task_cpu(p);
rq = task_rq_lock(p, &rf);
update_rq_clock(rq);
@@ -7344,21 +7345,15 @@ void migrate_enable(void)
p->migrate_disable_update = 0;
- WARN_ON(smp_processor_id() != task_cpu(p));
- if (!cpumask_test_cpu(task_cpu(p), &p->cpus_mask)) {
- const struct cpumask *cpu_valid_mask = cpu_active_mask;
- struct migration_arg arg;
- unsigned int dest_cpu;
-
- if (p->flags & PF_KTHREAD) {
- /*
- * Kernel threads are allowed on online && !active CPUs
- */
- cpu_valid_mask = cpu_online_mask;
- }
- dest_cpu = cpumask_any_and(cpu_valid_mask, &p->cpus_mask);
- arg.task = p;
- arg.dest_cpu = dest_cpu;
+ WARN_ON(smp_processor_id() != cpu);
+ if (!cpumask_test_cpu(cpu, &p->cpus_mask)) {
+ struct migration_arg arg = { p };
+ struct rq_flags rf;
+
+ rq = task_rq_lock(p, &rf);
+ update_rq_clock(rq);
+ arg.dest_cpu = select_fallback_rq(cpu, p);
+ task_rq_unlock(rq, p, &rf);
unpin_current_cpu();
preempt_lazy_enable();
--
2.24.1
next prev parent reply other threads:[~2020-01-23 20:40 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-23 20:39 [PATCH RT 00/30] Linux 4.19.94-rt39-rc2 Steven Rostedt
2020-01-23 20:39 ` [PATCH RT 01/30] i2c: exynos5: Remove IRQF_ONESHOT Steven Rostedt
2020-01-23 20:39 ` [PATCH RT 02/30] i2c: hix5hd2: " Steven Rostedt
2020-01-23 20:39 ` [PATCH RT 03/30] sched/deadline: Ensure inactive_timer runs in hardirq context Steven Rostedt
2020-01-23 20:39 ` [PATCH RT 04/30] thermal/x86_pkg_temp: make pkg_temp_lock a raw spinlock Steven Rostedt
2020-01-23 20:39 ` [PATCH RT 05/30] dma-buf: Use seqlock_t instread disabling preemption Steven Rostedt
2020-01-23 20:39 ` [PATCH RT 06/30] KVM: arm/arm64: Let the timer expire in hardirq context on RT Steven Rostedt
2020-01-23 20:39 ` [PATCH RT 07/30] x86: preempt: Check preemption level before looking at lazy-preempt Steven Rostedt
2020-01-23 20:39 ` [PATCH RT 08/30] hrtimer: Use READ_ONCE to access timer->base in hrimer_grab_expiry_lock() Steven Rostedt
2020-01-23 20:39 ` [PATCH RT 09/30] hrtimer: Dont grab the expiry lock for non-soft hrtimer Steven Rostedt
2020-01-23 20:39 ` [PATCH RT 10/30] hrtimer: Prevent using hrtimer_grab_expiry_lock() on migration_base Steven Rostedt
2020-04-27 13:10 ` Rasmus Villemoes
2020-04-27 19:06 ` Steven Rostedt
2020-04-27 19:26 ` Tom Zanussi
2020-04-28 6:51 ` Rasmus Villemoes
2020-04-28 7:03 ` Rasmus Villemoes
2020-04-28 12:59 ` Tom Zanussi
2020-04-28 13:07 ` Rasmus Villemoes
2020-04-28 13:43 ` Tom Zanussi
2020-01-23 20:39 ` [PATCH RT 11/30] hrtimer: Add a missing bracket and hide `migration_base on !SMP Steven Rostedt
2020-01-23 20:39 ` [PATCH RT 12/30] posix-timers: Unlock expiry lock in the early return Steven Rostedt
2020-01-23 20:39 ` [PATCH RT 14/30] sched: __set_cpus_allowed_ptr: Check cpus_mask, not cpus_ptr Steven Rostedt
2020-01-23 20:39 ` [PATCH RT 15/30] sched: Remove dead __migrate_disabled() check Steven Rostedt
2020-01-23 20:39 ` [PATCH RT 16/30] sched: migrate disable: Protect cpus_ptr with lock Steven Rostedt
2020-01-23 20:39 ` [PATCH RT 17/30] lib/smp_processor_id: Dont use cpumask_equal() Steven Rostedt
2020-01-23 20:39 ` [PATCH RT 18/30] futex: Make the futex_hash_bucket spinlock_t again and bring back its old state Steven Rostedt
2020-01-23 20:39 ` [PATCH RT 19/30] locking/rtmutex: Clean ->pi_blocked_on in the error case Steven Rostedt
2020-01-23 20:39 ` [PATCH RT 20/30] lib/ubsan: Dont seralize UBSAN report Steven Rostedt
2020-01-23 20:39 ` [PATCH RT 21/30] kmemleak: Change the lock of kmemleak_object to raw_spinlock_t Steven Rostedt
2020-01-23 20:39 ` Steven Rostedt [this message]
2020-01-23 20:39 ` [PATCH RT 23/30] sched: Lazy migrate_disable processing Steven Rostedt
2020-01-23 20:39 ` [PATCH RT 24/30] sched: migrate_enable: Use stop_one_cpu_nowait() Steven Rostedt
2020-01-23 20:39 ` [PATCH RT 25/30] Revert "ARM: Initialize split page table locks for vector page" Steven Rostedt
2020-01-23 20:39 ` [PATCH RT 26/30] locking: Make spinlock_t and rwlock_t a RCU section on RT Steven Rostedt
2020-01-23 20:39 ` [PATCH RT 27/30] sched/core: migrate_enable() must access takedown_cpu_task on !HOTPLUG_CPU Steven Rostedt
2020-01-23 20:39 ` [PATCH RT 28/30] lib/smp_processor_id: Adjust check_preemption_disabled() Steven Rostedt
2020-01-23 20:39 ` [PATCH RT 29/30] sched: migrate_enable: Busy loop until the migration request is completed Steven Rostedt
2020-01-23 20:40 ` [PATCH RT 30/30] Linux 4.19.94-rt39-rc2 Steven Rostedt
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