From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Mon, 15 Jul 2024 23:51:22 +0000 (-0700)
Subject: Merge tag 'wq-for-6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
X-Git-Tag: v6.11-rc1~220
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=b02c520fee6327eb4b25696c5e2d6732f362213c;p=thirdparty%2Flinux.git

Merge tag 'wq-for-6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq

Pull workqueue updates from Tejun Heo:

 - Lai fixed a bug where CPU hotplug and workqueue attribute changes
   race leaving some workqueues not fully updated. This involved
   refactoring and changing how online CPUs are tracked. The resulting
   code is cleaner.

 - Workqueue watchdog touch operation was causing too much cacheline
   contention on very large machines. Nicholas improved scalabililty by
   avoiding unnecessary global updates.

 - Code cleanups and minor rescuer behavior improvement.

 - The last commit 58629d4871e8 ("workqueue: Always queue work items to
   the newest PWQ for order workqueues") is a cherry-picked straggler
   commit from for-6.10-fixes, a fix for a bug which may not actually
   trigger.

* tag 'wq-for-6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: (24 commits)
  workqueue: Always queue work items to the newest PWQ for order workqueues
  workqueue: Rename wq_update_pod() to unbound_wq_update_pwq()
  workqueue: Remove the arguments @hotplug_cpu and @online from wq_update_pod()
  workqueue: Remove the argument @cpu_going_down from wq_calc_pod_cpumask()
  workqueue: Remove the unneeded cpumask empty check in wq_calc_pod_cpumask()
  workqueue: Remove cpus_read_lock() from apply_wqattrs_lock()
  workqueue: Simplify wq_calc_pod_cpumask() with wq_online_cpumask
  workqueue: Add wq_online_cpumask
  workqueue: Init rescuer's affinities as the wq's effective cpumask
  workqueue: Put PWQ allocation and WQ enlistment in the same lock C.S.
  workqueue: Move kthread_flush_worker() out of alloc_and_link_pwqs()
  workqueue: Make rescuer initialization as the last step of the creation of a new wq
  workqueue: Register sysfs after the whole creation of the new wq
  workqueue: Simplify goto statement
  workqueue: Update cpumasks after only applying it successfully
  workqueue: Improve scalability of workqueue watchdog touch
  workqueue: wq_watchdog_touch is always called with valid CPU
  workqueue: Remove useless pool->dying_workers
  workqueue: Detach workers directly in idle_cull_fn()
  workqueue: Don't bind the rescuer in the last working cpu
  ...
---

b02c520fee6327eb4b25696c5e2d6732f362213c
diff --cc kernel/workqueue.c
index 3fbaecfc88c28,e3ab09e70ba9a..dfd42c28e404b
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@@ -2738,31 -2732,8 +2733,28 @@@ static void worker_detach_from_pool(str
  
  	/* clear leftover flags without pool->lock after it is detached */
  	worker->flags &= ~(WORKER_UNBOUND | WORKER_REBOUND);
- 
- 	if (detach_completion)
- 		complete(detach_completion);
  }
  
 +static int format_worker_id(char *buf, size_t size, struct worker *worker,
 +			    struct worker_pool *pool)
 +{
 +	if (worker->rescue_wq)
 +		return scnprintf(buf, size, "kworker/R-%s",
 +				 worker->rescue_wq->name);
 +
 +	if (pool) {
 +		if (pool->cpu >= 0)
 +			return scnprintf(buf, size, "kworker/%d:%d%s",
 +					 pool->cpu, worker->id,
 +					 pool->attrs->nice < 0  ? "H" : "");
 +		else
 +			return scnprintf(buf, size, "kworker/u%d:%d",
 +					 pool->id, worker->id);
 +	} else {
 +		return scnprintf(buf, size, "kworker/dying");
 +	}
 +}
 +
  /**
   * create_worker - create a new workqueue worker
   * @pool: pool the new worker will belong to
@@@ -3367,10 -3333,9 +3350,8 @@@ woke_up
  		raw_spin_unlock_irq(&pool->lock);
  		set_pf_worker(false);
  
 -		set_task_comm(worker->task, "kworker/dying");
  		ida_free(&pool->worker_ida, worker->id);
- 		worker_detach_from_pool(worker);
  		WARN_ON_ONCE(!list_empty(&worker->entry));
- 		kfree(worker);
  		return 0;
  	}
  
@@@ -5558,9 -5500,10 +5516,11 @@@ static int wq_clamp_max_active(int max_
  static int init_rescuer(struct workqueue_struct *wq)
  {
  	struct worker *rescuer;
 +	char id_buf[WORKER_ID_LEN];
  	int ret;
  
+ 	lockdep_assert_held(&wq_pool_mutex);
+ 
  	if (!(wq->flags & WQ_MEM_RECLAIM))
  		return 0;