From: Marco Crivellari Date: Tue, 4 Nov 2025 10:00:32 +0000 (+0100) Subject: drm/i915: add WQ_PERCPU to alloc_workqueue users X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=c15d0056fb74d6a2efd7bb1d382305fbd8a93cd2;p=thirdparty%2Flinux.git 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 930c2ea566af ("workqueue: Add new WQ_PERCPU flag") Once migration is complete, WQ_UNBOUND can be removed and unbound will become the implicit default. Suggested-by: Tejun Heo Signed-off-by: Marco Crivellari Reviewed-by: Krzysztof Karas Link: https://patch.msgid.link/20251104100032.61525-4-marco.crivellari@suse.com Signed-off-by: Rodrigo Vivi --- diff --git a/drivers/gpu/drm/i915/display/intel_display_driver.c b/drivers/gpu/drm/i915/display/intel_display_driver.c index 967da2b41316b..23bfecc983e8d 100644 --- a/drivers/gpu/drm/i915/display/intel_display_driver.c +++ b/drivers/gpu/drm/i915/display/intel_display_driver.c @@ -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; diff --git a/drivers/gpu/drm/i915/i915_driver.c b/drivers/gpu/drm/i915/i915_driver.c index c2365853df1b2..79ded07b5db53 100644 --- a/drivers/gpu/drm/i915/i915_driver.c +++ b/drivers/gpu/drm/i915/i915_driver.c @@ -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; diff --git a/drivers/gpu/drm/i915/selftests/i915_sw_fence.c b/drivers/gpu/drm/i915/selftests/i915_sw_fence.c index 6c376338bb37a..6a305322e30db 100644 --- a/drivers/gpu/drm/i915/selftests/i915_sw_fence.c +++ b/drivers/gpu/drm/i915/selftests/i915_sw_fence.c @@ -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; diff --git a/drivers/gpu/drm/i915/selftests/mock_gem_device.c b/drivers/gpu/drm/i915/selftests/mock_gem_device.c index 210b9f8f7b611..27dc0e40a8d75 100644 --- a/drivers/gpu/drm/i915/selftests/mock_gem_device.c +++ b/drivers/gpu/drm/i915/selftests/mock_gem_device.c @@ -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;