Commit 5f93287f authored by Marco Crivellari's avatar Marco Crivellari Committed by Leon Romanovsky
Browse files

hfi1: WQ_PERCPU added to alloc_workqueue users 



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: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarMarco Crivellari <marco.crivellari@suse.com>
Link: https://patch.msgid.link/20251101163121.78400-4-marco.crivellari@suse.com


Signed-off-by: default avatarLeon Romanovsky <leon@kernel.org>
parent e60c5583

drivers/infiniband/hw/hfi1/init.c

+2 −2
Original line number Diff line number Diff line
@@ -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)

drivers/infiniband/hw/hfi1/opfn.c

+2 −2
Original line number Diff line number Diff line
@@ -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;