[RFC PATCH 0/2] ASoC: Move system_long_wq to system_dfl_long_wq

[RFC PATCH 0/2] ASoC: Move system_long_wq to system_dfl_long_wq

[Marco Crivellari]

Hello,

Currently the code uses the per-cpu workqueue system_long_wq to schedule
long running works.

Unbound works could benefit from scheduler task placement, to optimize
performance and power consumption. Another good reason to have this unbound,
is the "queue_delayed_work()" function, used to enqueue the work item.
More details on this will follow in the next section.

Recently, a new unbound workqueue specific for long running work has been
added:

    c116737e972e ("workqueue: Add system_dfl_long_wq for long unbound works")

~~~ Details about queue_delayed_work ~~~

system_long_wq is a per-cpu workqueue and it is used as a parameter of
queue_delayed_work(). This function schedule an item that it will later
be enqueued (once the timer will fire). __queue_delayed_work() does the job
receiving as "cpu" WORK_CPU_UNBOUND:

    if (housekeeping_enabled(HK_TYPE_TIMER)) {
    //      [....]
    } else {
            if (likely(cpu == WORK_CPU_UNBOUND))
                    add_timer_global(timer);
            else
                    add_timer_on(timer, cpu);
    }

The timer is global, so can fire everywhere, and the work item will be
enqueued where the timer fired.

Since the workqueue work doesn't rely on per-cpu variables, there is no
obvious reason that justify the use of a per-cpu workqueue. So change the
workqueue with the new system_dfl_long_wq, so that the used workqueue is
now unbound and can benefit from scheduler task placement.

Thanks!

Marco Crivellari (2):
  ASoC: cs42l43: Move long delayed work on system_dfl_long_wq
  ASoC: codecs: rt5640: Move long delayed work on system_dfl_long_wq

 sound/soc/codecs/cs42l43-jack.c |  5 +++--
 sound/soc/codecs/rt5640.c       | 13 +++++++------
 2 files changed, 10 insertions(+), 8 deletions(-)

-- 
2.53.0

[RFC PATCH 1/2] ASoC: cs42l43: Move long delayed work on system_dfl_long_wq

[Marco Crivellari]

Move long delayed work on system_dfl_long_wq

Currently the code enqueue work items using {queue|mod}_delayed_work(),
using system_long_wq. This workqueue should be used when long works are
expected and it is a per-cpu workqueue.

The function(s) end up calling __queue_delayed_work(), which set a global
timer that could fire anywhere, enqueuing the work where the timer fired.

Unbound works could benefit from scheduler task placement, to optimize
performance and power consumption. Long work shouldn't stick to a single
CPU.

Recently, a new unbound workqueue specific for long running work has
been added:

    c116737e972e ("workqueue: Add system_dfl_long_wq for long unbound works")

Since the workqueue work doesn't rely on per-cpu variables, there is no
obvious reason that justify the use of a per-cpu workqueue. So change
system_long_wq with system_dfl_long_wq so that the work may benefit from
scheduler task placement.

Cc: David Rhodes <david.rhodes@cirrus.com>
Cc: Richard Fitzgerald <rf@opensource.cirrus.com>
Cc: <patches@opensource.cirrus.com>
Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>
---
 sound/soc/codecs/cs42l43-jack.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/sound/soc/codecs/cs42l43-jack.c b/sound/soc/codecs/cs42l43-jack.c
index 3e04e6897b14..934666295ee3 100644
--- a/sound/soc/codecs/cs42l43-jack.c
+++ b/sound/soc/codecs/cs42l43-jack.c
@@ -805,7 +805,7 @@ irqreturn_t cs42l43_tip_sense(int irq, void *data)
 	if (priv->suspend_jack_debounce)
 		db_delay += priv->tip_fall_db_ms + priv->tip_rise_db_ms;
 
-	queue_delayed_work(system_long_wq, &priv->tip_sense_work,
+	queue_delayed_work(system_dfl_long_wq, &priv->tip_sense_work,
 			   msecs_to_jiffies(db_delay));
 
 	return IRQ_HANDLED;
@@ -932,7 +932,8 @@ int cs42l43_jack_put(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *u
 	snd_soc_jack_report(priv->jack_hp, 0, 0xFFFF);
 
 	if (!override) {
-		queue_delayed_work(system_long_wq, &priv->tip_sense_work, 0);
+		queue_delayed_work(system_dfl_long_wq, &priv->tip_sense_work,
+				   0);
 	} else {
 		override--;
 
-- 
2.53.0

Re: [RFC PATCH 1/2] ASoC: cs42l43: Move long delayed work on system_dfl_long_wq

[Charles Keepax]

On Fri, May 08, 2026 at 05:03:18PM +0200, Marco Crivellari wrote:
> Move long delayed work on system_dfl_long_wq
> 
> Currently the code enqueue work items using {queue|mod}_delayed_work(),
> using system_long_wq. This workqueue should be used when long works are
> expected and it is a per-cpu workqueue.
> 
> The function(s) end up calling __queue_delayed_work(), which set a global
> timer that could fire anywhere, enqueuing the work where the timer fired.
> 
> Unbound works could benefit from scheduler task placement, to optimize
> performance and power consumption. Long work shouldn't stick to a single
> CPU.
> 
> Recently, a new unbound workqueue specific for long running work has
> been added:
> 
>     c116737e972e ("workqueue: Add system_dfl_long_wq for long unbound works")
> 
> Since the workqueue work doesn't rely on per-cpu variables, there is no
> obvious reason that justify the use of a per-cpu workqueue. So change
> system_long_wq with system_dfl_long_wq so that the work may benefit from
> scheduler task placement.
> 
> Cc: David Rhodes <david.rhodes@cirrus.com>
> Cc: Richard Fitzgerald <rf@opensource.cirrus.com>
> Cc: <patches@opensource.cirrus.com>
> Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>
> ---

Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com>

Thanks,
Charles

[RFC PATCH 2/2] ASoC: codecs: rt5640: Move long delayed work on system_dfl_long_wq

[Marco Crivellari]

Currently the code enqueue work items using {queue|mod}_delayed_work(),
using system_long_wq. This workqueue should be used when long works are
expected and it is a per-cpu workqueue.

The function(s) end up calling __queue_delayed_work(), which set a global
timer that could fire anywhere, enqueuing the work where the timer fired.

Unbound works could benefit from scheduler task placement, to optimize
performance and power consumption. Long work shouldn't stick to a single
CPU.

Recently, a new unbound workqueue specific for long running work has
been added:

    c116737e972e ("workqueue: Add system_dfl_long_wq for long unbound works")

Since the workqueue work doesn't rely on per-cpu variables, there is no
obvious reason that justify the use of a per-cpu workqueue. So change
system_long_wq with system_dfl_long_wq so that the work may benefit from
scheduler task placement.

Cc: Oder Chiou <oder_chiou@realtek.com>
Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>
---
 sound/soc/codecs/rt5640.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/sound/soc/codecs/rt5640.c b/sound/soc/codecs/rt5640.c
index f6c6294e1588..1a5bb72b7d03 100644
--- a/sound/soc/codecs/rt5640.c
+++ b/sound/soc/codecs/rt5640.c
@@ -2397,7 +2397,7 @@ static void rt5640_jack_work(struct work_struct *work)
 		 * disabled the OVCD IRQ, the IRQ pin will stay high and as
 		 * we react to edges, we miss the unplug event -> recheck.
 		 */
-		queue_delayed_work(system_long_wq, &rt5640->jack_work, 0);
+		queue_delayed_work(system_dfl_long_wq, &rt5640->jack_work, 0);
 	}
 }
 
@@ -2410,7 +2410,8 @@ static irqreturn_t rt5640_irq(int irq, void *data)
 		delay = 100;
 
 	if (rt5640->jack)
-		mod_delayed_work(system_long_wq, &rt5640->jack_work, delay);
+		mod_delayed_work(system_dfl_long_wq, &rt5640->jack_work,
+				 delay);
 
 	return IRQ_HANDLED;
 }
@@ -2419,7 +2420,7 @@ static irqreturn_t rt5640_jd_gpio_irq(int irq, void *data)
 {
 	struct rt5640_priv *rt5640 = data;
 
-	queue_delayed_work(system_long_wq, &rt5640->jack_work,
+	queue_delayed_work(system_dfl_long_wq, &rt5640->jack_work,
 			   msecs_to_jiffies(JACK_SETTLE_TIME));
 
 	return IRQ_HANDLED;
@@ -2579,7 +2580,7 @@ static void rt5640_enable_jack_detect(struct snd_soc_component *component,
 	rt5640->irq_requested = true;
 
 	/* sync initial jack state */
-	queue_delayed_work(system_long_wq, &rt5640->jack_work, 0);
+	queue_delayed_work(system_dfl_long_wq, &rt5640->jack_work, 0);
 }
 
 static const struct snd_soc_dapm_route rt5640_hda_jack_dapm_routes[] = {
@@ -2632,7 +2633,7 @@ static void rt5640_enable_hda_jack_detect(
 	rt5640->irq_requested = true;
 
 	/* sync initial jack state */
-	queue_delayed_work(system_long_wq, &rt5640->jack_work, 0);
+	queue_delayed_work(system_dfl_long_wq, &rt5640->jack_work, 0);
 
 	snd_soc_dapm_add_routes(dapm, rt5640_hda_jack_dapm_routes,
 		ARRAY_SIZE(rt5640_hda_jack_dapm_routes));
@@ -2860,7 +2861,7 @@ static int rt5640_resume(struct snd_soc_component *component)
 		}
 
 		enable_irq(rt5640->irq);
-		queue_delayed_work(system_long_wq, &rt5640->jack_work, 0);
+		queue_delayed_work(system_dfl_long_wq, &rt5640->jack_work, 0);
 	}
 
 	return 0;
-- 
2.53.0

Re: [RFC PATCH 0/2] ASoC: Move system_long_wq to system_dfl_long_wq

[Mark Brown]

On Fri, 08 May 2026 17:03:17 +0200, Marco Crivellari wrote:
> ASoC: Move system_long_wq to system_dfl_long_wq
> 
> Hello,
> 
> Currently the code uses the per-cpu workqueue system_long_wq to schedule
> long running works.
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-7.2

Thanks!

[1/2] ASoC: cs42l43: Move long delayed work on system_dfl_long_wq
      https://git.kernel.org/broonie/sound/c/45f7d7af0eeb
[2/2] ASoC: codecs: rt5640: Move long delayed work on system_dfl_long_wq
      https://git.kernel.org/broonie/sound/c/11b92ac8df44

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

Re: [RFC PATCH 0/2] ASoC: Move system_long_wq to system_dfl_long_wq

[Marco Crivellari]

On Mon, May 11, 2026 at 2:02 PM Mark Brown <broonie@kernel.org> wrote:
> [...]
> Applied to
>
>    https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-7.2
>
> Thanks!
>
> [1/2] ASoC: cs42l43: Move long delayed work on system_dfl_long_wq
>       https://git.kernel.org/broonie/sound/c/45f7d7af0eeb
> [2/2] ASoC: codecs: rt5640: Move long delayed work on system_dfl_long_wq
>       https://git.kernel.org/broonie/sound/c/11b92ac8df44

Many thanks!

-- 

Marco Crivellari

SUSE Labs