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From: Marco Crivellari <marco.crivellari@suse.com>
To: linux-kernel@vger.kernel.org
Cc: Tejun Heo <tj@kernel.org>, Lai Jiangshan <jiangshanlai@gmail.com>,
	Frederic Weisbecker <frederic@kernel.org>,
	Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
	Marco Crivellari <marco.crivellari@suse.com>,
	Michal Hocko <mhocko@suse.com>, Jens Axboe <axboe@kernel.dk>
Subject: [PATCH v2 1/2] block: Add WQ_PERCPU to alloc_workqueue users
Date: Mon, 23 Feb 2026 10:29:19 +0100	[thread overview]
Message-ID: <20260223092920.60424-2-marco.crivellari@suse.com> (raw)
In-Reply-To: <20260223092920.60424-1-marco.crivellari@suse.com>

This continues the effort to refactor workqueue APIs, which began with
the introduction of new workqueues and a new alloc_workqueue flag in:

   commit 128ea9f6ccfb ("workqueue: Add system_percpu_wq and system_dfl_wq")
   commit 930c2ea566af ("workqueue: Add new WQ_PERCPU flag")

The refactoring is going to alter the default behavior of
alloc_workqueue() to be unbound by default.

With the introduction of the WQ_PERCPU flag (equivalent to !WQ_UNBOUND),
any alloc_workqueue() caller that doesn’t explicitly specify WQ_UNBOUND
must now use WQ_PERCPU. For more details see the Link tag below.

In order to keep alloc_workqueue() behavior identical, explicitly request
WQ_PERCPU.

Link: https://lore.kernel.org/all/20250221112003.1dSuoGyc@linutronix.de/
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>
---
 block/bio-integrity-auto.c | 2 +-
 block/bio.c                | 2 +-
 block/blk-core.c           | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/block/bio-integrity-auto.c b/block/bio-integrity-auto.c
index 44dcdf7520c5..a2bccb3c4baa 100644
--- a/block/bio-integrity-auto.c
+++ b/block/bio-integrity-auto.c
@@ -183,7 +183,7 @@ static int __init blk_integrity_auto_init(void)
 	 * Make it highpri CPU intensive wq with max concurrency of 1.
 	 */
 	kintegrityd_wq = alloc_workqueue("kintegrityd", WQ_MEM_RECLAIM |
-					 WQ_HIGHPRI | WQ_CPU_INTENSIVE, 1);
+					 WQ_HIGHPRI | WQ_CPU_INTENSIVE | WQ_PERCPU, 1);
 	if (!kintegrityd_wq)
 		panic("Failed to create kintegrityd\n");
 	return 0;
diff --git a/block/bio.c b/block/bio.c
index d80d5d26804e..fd8073fbffb2 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1956,7 +1956,7 @@ int bioset_init(struct bio_set *bs,
 
 	if (flags & BIOSET_NEED_RESCUER) {
 		bs->rescue_workqueue = alloc_workqueue("bioset",
-							WQ_MEM_RECLAIM, 0);
+							WQ_MEM_RECLAIM | WQ_PERCPU, 0);
 		if (!bs->rescue_workqueue)
 			goto bad;
 	}
diff --git a/block/blk-core.c b/block/blk-core.c
index 474700ffaa1c..17450058ea6d 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1282,7 +1282,7 @@ int __init blk_dev_init(void)
 
 	/* used for unplugging and affects IO latency/throughput - HIGHPRI */
 	kblockd_workqueue = alloc_workqueue("kblockd",
-					    WQ_MEM_RECLAIM | WQ_HIGHPRI, 0);
+					    WQ_MEM_RECLAIM | WQ_HIGHPRI | WQ_PERCPU, 0);
 	if (!kblockd_workqueue)
 		panic("Failed to create kblockd\n");
 
-- 
2.52.0


  reply	other threads:[~2026-02-23  9:29 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-02-23  9:29 [PATCH v2 0/2] " Marco Crivellari
2026-02-23  9:29 ` Marco Crivellari [this message]
2026-02-23  9:29 ` [PATCH v2 2/2] block/blk-throttle: " Marco Crivellari
2026-03-18 15:31 ` [PATCH v2 0/2] " Marco Crivellari
2026-03-27 16:06 ` Marco Crivellari
2026-04-09  9:49 ` Marco Crivellari
2026-04-17 20:39 ` Jens Axboe
2026-04-20  7:57   ` Marco Crivellari

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