Unverified Commit c15d0056 authored by Marco Crivellari's avatar Marco Crivellari Committed by Rodrigo Vivi
Browse files

drm/i915: add WQ_PERCPU 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.

This patch continues the effort to refactor worqueue APIs, which has
begun with the change introducing new workqueues:

commit 930c2ea5 ("workqueue: Add new WQ_PERCPU flag")

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

Suggested-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarMarco Crivellari <marco.crivellari@suse.com>
Reviewed-by: default avatarKrzysztof Karas <krzysztof.karas@intel.com>
Link: https://patch.msgid.link/20251104100032.61525-4-marco.crivellari@suse.com


Signed-off-by: default avatarRodrigo Vivi <rodrigo.vivi@intel.com>
parent 4fb289d3

drivers/gpu/drm/i915/display/intel_display_driver.c

+2 −2
Original line number Diff line number Diff line
@@ -241,13 +241,13 @@ int intel_display_driver_probe_noirq(struct intel_display *display) 
		goto cleanup_wq_modeset;

	}



	display->wq.cleanup = alloc_workqueue("i915_cleanup", WQ_HIGHPRI, 0);

	display->wq.cleanup = alloc_workqueue("i915_cleanup", WQ_HIGHPRI | WQ_PERCPU, 0);

	if (!display->wq.cleanup) {

		ret = -ENOMEM;

		goto cleanup_wq_flip;

	}



	display->wq.unordered = alloc_workqueue("display_unordered", 0, 0);

	display->wq.unordered = alloc_workqueue("display_unordered", WQ_PERCPU, 0);

	if (!display->wq.unordered) {

		ret = -ENOMEM;

		goto cleanup_wq_cleanup;

drivers/gpu/drm/i915/i915_driver.c

+2 −1
Original line number Diff line number Diff line
@@ -154,7 +154,8 @@ static int i915_workqueues_init(struct drm_i915_private *dev_priv) 
	 * to be scheduled on the system_percpu_wq before moving to a driver

	 * instance due deprecation of flush_scheduled_work().

	 */

	dev_priv->unordered_wq = alloc_workqueue("i915-unordered", 0, 0);

	dev_priv->unordered_wq = alloc_workqueue("i915-unordered", WQ_PERCPU,

						 0);

	if (dev_priv->unordered_wq == NULL)

		goto out_free_wq;

drivers/gpu/drm/i915/selftests/i915_sw_fence.c

+1 −1
Original line number Diff line number Diff line
@@ -526,7 +526,7 @@ static int test_ipc(void *arg) 
	struct workqueue_struct *wq;

	int ret = 0;



	wq = alloc_workqueue("i1915-selftest", 0, 0);

	wq = alloc_workqueue("i1915-selftest", WQ_PERCPU, 0);

	if (wq == NULL)

		return -ENOMEM;

drivers/gpu/drm/i915/selftests/mock_gem_device.c

+1 −1
Original line number Diff line number Diff line
@@ -223,7 +223,7 @@ struct drm_i915_private *mock_gem_device(void) 
	if (!i915->wq)

		goto err_drv;



	i915->unordered_wq = alloc_workqueue("mock-unordered", 0, 0);

	i915->unordered_wq = alloc_workqueue("mock-unordered", WQ_PERCPU, 0);

	if (!i915->unordered_wq)

		goto err_wq;