From: Tejun Heo <tj@kernel.org>
Date: Tue, 22 Apr 2025 19:29:23 +0000 (-1000)
Subject: Merge branch 'for-6.15-fixes' into for-6.16
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=ac47c272b2668cd28e22b58921f3fd2b9daae2c7;p=users%2Fwilly%2Fxarray.git

Merge branch 'for-6.15-fixes' into for-6.16

a11d6784d731 ("sched_ext: Fix missing rq lock in scx_bpf_cpuperf_set()")
added a call to scx_ops_error() which was renamed to scx_error() in
for-6.16. Fix it up.
---

ac47c272b2668cd28e22b58921f3fd2b9daae2c7
diff --cc kernel/sched/ext.c
index bb0873411d79,ac79067dc87e..a175b622716c
--- a/kernel/sched/ext.c
+++ b/kernel/sched/ext.c
@@@ -3440,13 -3477,13 +3473,13 @@@ static void handle_hotplug(struct rq *r
  		scx_idle_update_selcpu_topology(&scx_ops);
  
  	if (online && SCX_HAS_OP(cpu_online))
- 		SCX_CALL_OP(SCX_KF_UNLOCKED, cpu_online, cpu);
+ 		SCX_CALL_OP(SCX_KF_UNLOCKED, cpu_online, rq, cpu);
  	else if (!online && SCX_HAS_OP(cpu_offline))
- 		SCX_CALL_OP(SCX_KF_UNLOCKED, cpu_offline, cpu);
+ 		SCX_CALL_OP(SCX_KF_UNLOCKED, cpu_offline, rq, cpu);
  	else
 -		scx_ops_exit(SCX_ECODE_ACT_RESTART | SCX_ECODE_RSN_HOTPLUG,
 -			     "cpu %d going %s, exiting scheduler", cpu,
 -			     online ? "online" : "offline");
 +		scx_exit(SCX_ECODE_ACT_RESTART | SCX_ECODE_RSN_HOTPLUG,
 +			 "cpu %d going %s, exiting scheduler", cpu,
 +			 online ? "online" : "offline");
  }
  
  void scx_rq_activate(struct rq *rq)
@@@ -3661,11 -3699,12 +3694,12 @@@ static int scx_init_task(struct task_st
  	return 0;
  }
  
 -static void scx_ops_enable_task(struct task_struct *p)
 +static void scx_enable_task(struct task_struct *p)
  {
+ 	struct rq *rq = task_rq(p);
  	u32 weight;
  
- 	lockdep_assert_rq_held(task_rq(p));
+ 	lockdep_assert_rq_held(rq);
  
  	/*
  	 * Set the weight before calling ops.enable() so that the scheduler
@@@ -3683,12 -3722,14 +3717,14 @@@
  	scx_set_task_state(p, SCX_TASK_ENABLED);
  
  	if (SCX_HAS_OP(set_weight))
- 		SCX_CALL_OP_TASK(SCX_KF_REST, set_weight, p, p->scx.weight);
+ 		SCX_CALL_OP_TASK(SCX_KF_REST, set_weight, rq, p, p->scx.weight);
  }
  
 -static void scx_ops_disable_task(struct task_struct *p)
 +static void scx_disable_task(struct task_struct *p)
  {
- 	lockdep_assert_rq_held(task_rq(p));
+ 	struct rq *rq = task_rq(p);
+ 
+ 	lockdep_assert_rq_held(rq);
  	WARN_ON_ONCE(scx_get_task_state(p) != SCX_TASK_ENABLED);
  
  	if (SCX_HAS_OP(disable))
@@@ -7052,13 -7113,32 +7088,32 @@@ __bpf_kfunc void scx_bpf_cpuperf_set(s3
  	}
  
  	if (ops_cpu_valid(cpu, NULL)) {
- 		struct rq *rq = cpu_rq(cpu);
+ 		struct rq *rq = cpu_rq(cpu), *locked_rq = scx_locked_rq();
+ 		struct rq_flags rf;
+ 
+ 		/*
+ 		 * When called with an rq lock held, restrict the operation
+ 		 * to the corresponding CPU to prevent ABBA deadlocks.
+ 		 */
+ 		if (locked_rq && rq != locked_rq) {
 -			scx_ops_error("Invalid target CPU %d", cpu);
++			scx_error("Invalid target CPU %d", cpu);
+ 			return;
+ 		}
+ 
+ 		/*
+ 		 * If no rq lock is held, allow to operate on any CPU by
+ 		 * acquiring the corresponding rq lock.
+ 		 */
+ 		if (!locked_rq) {
+ 			rq_lock_irqsave(rq, &rf);
+ 			update_rq_clock(rq);
+ 		}
  
  		rq->scx.cpuperf_target = perf;
+ 		cpufreq_update_util(rq, 0);
  
- 		rcu_read_lock_sched_notrace();
- 		cpufreq_update_util(cpu_rq(cpu), 0);
- 		rcu_read_unlock_sched_notrace();
+ 		if (!locked_rq)
+ 			rq_unlock_irqrestore(rq, &rf);
  	}
  }