diff options
| author | Marco Crivellari <marco.crivellari@suse.com> | 2025-11-01 17:31:15 +0100 |
|---|---|---|
| committer | Leon Romanovsky <leon@kernel.org> | 2025-11-06 02:23:23 -0500 |
| commit | 7196156b0ce3dc4cdbda5c09897708b2e1081de1 (patch) | |
| tree | 3367bc46b98f50fd463cf937d531782074e778c0 | |
| parent | 5267feda50680c73e33b118dbebfb961d6a864bd (diff) | |
IB/rdmavt: 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/20251101163121.78400-6-marco.crivellari@suse.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>
| -rw-r--r-- | drivers/infiniband/sw/rdmavt/cq.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/infiniband/sw/rdmavt/cq.c b/drivers/infiniband/sw/rdmavt/cq.c index 0ca2743f1075..e7835ca70e2b 100644 --- a/drivers/infiniband/sw/rdmavt/cq.c +++ b/drivers/infiniband/sw/rdmavt/cq.c @@ -518,7 +518,8 @@ int rvt_poll_cq(struct ib_cq *ibcq, int num_entries, struct ib_wc *entry) */ int rvt_driver_cq_init(void) { - comp_vector_wq = alloc_workqueue("%s", WQ_HIGHPRI | WQ_CPU_INTENSIVE, + comp_vector_wq = alloc_workqueue("%s", + WQ_HIGHPRI | WQ_CPU_INTENSIVE | WQ_PERCPU, 0, "rdmavt_cq"); if (!comp_vector_wq) return -ENOMEM; |