From: Marco Crivellari Date: Fri, 5 Sep 2025 09:06:41 +0000 (+0200) Subject: power: supply: WQ_PERCPU added to alloc_workqueue users X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=cc2ec444e461b6ca2bc73cd7cbd06aaf15bdfa1a;p=users%2Fhch%2Fmisc.git power: supply: 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 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 patch adds a new WQ_PERCPU flag to explicitly request the use of the per-CPU behavior. Both flags coexist for one release cycle to allow callers to transition their calls. Once migration is complete, WQ_UNBOUND can be removed and unbound will become the implicit default. 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. All existing users have been updated accordingly. Suggested-by: Tejun Heo Signed-off-by: Marco Crivellari Link: https://lore.kernel.org/r/20250905090641.106297-3-marco.crivellari@suse.com Signed-off-by: Sebastian Reichel --- diff --git a/drivers/power/supply/ab8500_btemp.c b/drivers/power/supply/ab8500_btemp.c index b00c84fbc33c..e5202a7b6209 100644 --- a/drivers/power/supply/ab8500_btemp.c +++ b/drivers/power/supply/ab8500_btemp.c @@ -667,7 +667,8 @@ static int ab8500_btemp_bind(struct device *dev, struct device *master, /* Create a work queue for the btemp */ di->btemp_wq = - alloc_workqueue("ab8500_btemp_wq", WQ_MEM_RECLAIM, 0); + alloc_workqueue("ab8500_btemp_wq", WQ_MEM_RECLAIM | WQ_PERCPU, + 0); if (di->btemp_wq == NULL) { dev_err(dev, "failed to create work queue\n"); return -ENOMEM; diff --git a/drivers/power/supply/ipaq_micro_battery.c b/drivers/power/supply/ipaq_micro_battery.c index 7e0568a5353f..ff8573a5ca6d 100644 --- a/drivers/power/supply/ipaq_micro_battery.c +++ b/drivers/power/supply/ipaq_micro_battery.c @@ -232,7 +232,8 @@ static int micro_batt_probe(struct platform_device *pdev) return -ENOMEM; mb->micro = dev_get_drvdata(pdev->dev.parent); - mb->wq = alloc_workqueue("ipaq-battery-wq", WQ_MEM_RECLAIM, 0); + mb->wq = alloc_workqueue("ipaq-battery-wq", + WQ_MEM_RECLAIM | WQ_PERCPU, 0); if (!mb->wq) return -ENOMEM;