From: Scott Wood Date: Tue, 24 Sep 2019 14:36:41 +0200 Subject: [PATCH 297/353] =?UTF-8?q?sched:=20migrate=5Fdis/enable:=20Use=20?= =?UTF-8?q?sleeping=5Flock=E2=80=A6()=20to=20annotate=20sleeping=20points?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Origin: https://git.kernel.org/cgit/linux/kernel/git/rt/linux-stable-rt.git/commit?id=b49a31f9d5d7fdda03f5bcb45ad967ef89f9821d [ Upstream commit 4230dd3824c3e1785504e6f757ce79a4b55651fa ] Without this, rcu_note_context_switch() will complain if an RCU read lock is held when migrate_enable() calls stop_one_cpu(). Likewise when migrate_disable() calls pin_current_cpu() which calls __read_rt_lock() -- which bypasses the part of the mutex code that calls sleeping_lock_inc(). Signed-off-by: Scott Wood Signed-off-by: Steven Rostedt (VMware) [bigeasy: use sleeping_lock_…() ] Signed-off-by: Sebastian Andrzej Siewior --- kernel/cpu.c | 2 ++ kernel/sched/core.c | 3 +++ 2 files changed, 5 insertions(+) diff --git a/kernel/cpu.c b/kernel/cpu.c index 396394ebbc5b..4bf82665f28c 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -310,7 +310,9 @@ void pin_current_cpu(void) preempt_lazy_enable(); preempt_enable(); + sleeping_lock_inc(); __read_rt_lock(cpuhp_pin); + sleeping_lock_dec(); preempt_disable(); preempt_lazy_disable(); diff --git a/kernel/sched/core.c b/kernel/sched/core.c index dded9ca916eb..223a5a23834a 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -7369,7 +7369,10 @@ void migrate_enable(void) unpin_current_cpu(); preempt_lazy_enable(); preempt_enable(); + + sleeping_lock_inc(); stop_one_cpu(task_cpu(p), migration_cpu_stop, &arg); + sleeping_lock_dec(); tlb_migrate_finish(p->mm); return;