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hfi1: WQ_PERCPU added to alloc_workqueue users

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Currently if a user enqueue a work item using schedule_delayed_work() the
used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use
WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to
schedule_work() that is using system_wq and queue_work(), that makes use
again of WORK_CPU_UNBOUND.
This lack of consistentcy cannot be addressed without refactoring the API.

alloc_workqueue() treats all queues as per-CPU by default, while unbound
workqueues must opt-in via WQ_UNBOUND.

This default is suboptimal: most workloads benefit from unbound queues,
allowing the scheduler to place worker threads where they’re needed and
reducing noise when CPUs are isolated.

This change adds a new WQ_PERCPU flag to explicitly request
alloc_workqueue() to be per-cpu when WQ_UNBOUND has not been specified.

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.

Once migration is complete, WQ_UNBOUND can be removed and unbound will
become the implicit default.

CC: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>
Link: https://patch.msgid.link/20251101163121.78400-4-marco.crivellari@suse.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>
This commit is contained in:
Marco Crivellari
2025-11-01 17:31:13 +01:00
committed by Leon Romanovsky
parent e60c5583b6
commit 5f93287fa9
2 changed files with 4 additions and 4 deletions
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4
drivers/infiniband/hw/hfi1/init.c
View File

@@ -745,8 +745,8 @@ static int create_workqueues(struct hfi1_devdata *dd)
ppd->hfi1_wq =
alloc_workqueue(
"hfi%d_%d",
WQ_SYSFS | WQ_HIGHPRI | WQ_CPU_INTENSIVE |
WQ_MEM_RECLAIM,
WQ_SYSFS | WQ_HIGHPRI | WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM |
WQ_PERCPU,
HFI1_MAX_ACTIVE_WORKQUEUE_ENTRIES,
dd->unit, pidx);
if (!ppd->hfi1_wq)

4
drivers/infiniband/hw/hfi1/opfn.c
View File

@@ -305,8 +305,8 @@ void opfn_trigger_conn_request(struct rvt_qp *qp, u32 bth1)
int opfn_init(void)
{
opfn_wq = alloc_workqueue("hfi_opfn",
WQ_SYSFS | WQ_HIGHPRI | WQ_CPU_INTENSIVE |
WQ_MEM_RECLAIM,
WQ_SYSFS | WQ_HIGHPRI | WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM |
WQ_PERCPU,
HFI1_MAX_ACTIVE_WORKQUEUE_ENTRIES);
if (!opfn_wq)
return -ENOMEM;