[PATCH v2 1/2] block: Add WQ_PERCPU to alloc_workqueue users

From: Marco Crivellari

Date: Mon Feb 23 2026 - 04:31:43 EST


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@xxxxxxxxxxxxx/
Suggested-by: Tejun Heo <tj@xxxxxxxxxx>
Signed-off-by: Marco Crivellari <marco.crivellari@xxxxxxxx>
---
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