Commit 87437656 authored by Tejun Heo's avatar Tejun Heo
Browse files

workqueue: Merge branch 'for-6.5-fixes' into for-6.6 



Unbound workqueue execution locality improvement patchset is about to
applied which will cause merge conflicts with changes in for-6.5-fixes.
Let's avoid future merge conflict by pulling in for-6.5-fixes.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parents 9680540c aa6fde93

kernel/workqueue.c

+42 −1
Original line number Diff line number Diff line
@@ -52,6 +52,7 @@ 
#include <linux/sched/debug.h>

#include <linux/nmi.h>

#include <linux/kvm_para.h>

#include <linux/delay.h>



#include "workqueue_internal.h"
@@ -338,8 +339,10 @@ static cpumask_var_t *wq_numa_possible_cpumask; 
 * Per-cpu work items which run for longer than the following threshold are

 * automatically considered CPU intensive and excluded from concurrency

 * management to prevent them from noticeably delaying other per-cpu work items.

 * ULONG_MAX indicates that the user hasn't overridden it with a boot parameter.

 * The actual value is initialized in wq_cpu_intensive_thresh_init().

 */

static unsigned long wq_cpu_intensive_thresh_us = 10000;

static unsigned long wq_cpu_intensive_thresh_us = ULONG_MAX;

module_param_named(cpu_intensive_thresh_us, wq_cpu_intensive_thresh_us, ulong, 0644);



static bool wq_disable_numa;
@@ -6516,6 +6519,42 @@ void __init workqueue_init_early(void) 
	       !system_freezable_power_efficient_wq);

}



static void __init wq_cpu_intensive_thresh_init(void)

{

	unsigned long thresh;

	unsigned long bogo;



	/* if the user set it to a specific value, keep it */

	if (wq_cpu_intensive_thresh_us != ULONG_MAX)

		return;



	/*

	 * The default of 10ms is derived from the fact that most modern (as of

	 * 2023) processors can do a lot in 10ms and that it's just below what

	 * most consider human-perceivable. However, the kernel also runs on a

	 * lot slower CPUs including microcontrollers where the threshold is way

	 * too low.

	 *

	 * Let's scale up the threshold upto 1 second if BogoMips is below 4000.

	 * This is by no means accurate but it doesn't have to be. The mechanism

	 * is still useful even when the threshold is fully scaled up. Also, as

	 * the reports would usually be applicable to everyone, some machines

	 * operating on longer thresholds won't significantly diminish their

	 * usefulness.

	 */

	thresh = 10 * USEC_PER_MSEC;



	/* see init/calibrate.c for lpj -> BogoMIPS calculation */

	bogo = max_t(unsigned long, loops_per_jiffy / 500000 * HZ, 1);

	if (bogo < 4000)

		thresh = min_t(unsigned long, thresh * 4000 / bogo, USEC_PER_SEC);



	pr_debug("wq_cpu_intensive_thresh: lpj=%lu BogoMIPS=%lu thresh_us=%lu\n",

		 loops_per_jiffy, bogo, thresh);



	wq_cpu_intensive_thresh_us = thresh;

}



/**

 * workqueue_init - bring workqueue subsystem fully online

 *
@@ -6531,6 +6570,8 @@ void __init workqueue_init(void) 
	struct worker_pool *pool;

	int cpu, bkt;



	wq_cpu_intensive_thresh_init();



	/*

	 * It'd be simpler to initialize NUMA in workqueue_init_early() but

	 * CPU to node mapping may not be available that early on some

lib/Kconfig.debug

+1 −1
Original line number Diff line number Diff line
@@ -1200,7 +1200,7 @@ config WQ_CPU_INTENSIVE_REPORT 
	help

	  Say Y here to enable reporting of concurrency-managed per-cpu work

	  items that hog CPUs for longer than

	  workqueue.cpu_intensive_threshold_us. Workqueue automatically

	  workqueue.cpu_intensive_thresh_us. Workqueue automatically

	  detects and excludes them from concurrency management to prevent

	  them from stalling other per-cpu work items. Occassional

	  triggering may not necessarily indicate a problem. Repeated