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: 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>

diff --git a/drivers/infiniband/hw/hfi1/init.c b/drivers/infiniband/hw/hfi1/init.c
index b35f92e7d865f0ae38d8d6adc2f43d4b1ef1faaa..e4aef102dac0db8094175a08112fc7ab23828c84 100644 (file)
--- a/drivers/infiniband/hw/hfi1/init.c
+++ b/drivers/infiniband/hw/hfi1/init.c
@@ -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)

diff --git a/drivers/infiniband/hw/hfi1/opfn.c b/drivers/infiniband/hw/hfi1/opfn.c
index 370a5a8eaa716bc177386b0f9813783757a6d60e..6e0e3458d202fa1fe40c359cf0f43872f2aecf63 100644 (file)
--- a/drivers/infiniband/hw/hfi1/opfn.c
+++ b/drivers/infiniband/hw/hfi1/opfn.c
@@ -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;