diff options
| author | Marco Crivellari <marco.crivellari@suse.com> | 2025-09-05 11:06:41 +0200 |
|---|---|---|
| committer | Sebastian Reichel <sebastian.reichel@collabora.com> | 2025-09-09 00:53:46 +0200 |
| commit | cc2ec444e461b6ca2bc73cd7cbd06aaf15bdfa1a (patch) | |
| tree | 77a0613f4857b5e4a8c2060fbb70377e7f0c5ef3 | |
| parent | c4a7748b551e5a06fe9a3862001192b1b5cfe195 (diff) | |
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 <tj@kernel.org>
Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>
Link: https://lore.kernel.org/r/20250905090641.106297-3-marco.crivellari@suse.com
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
| -rw-r--r-- | drivers/power/supply/ab8500_btemp.c | 3 | ||||
| -rw-r--r-- | drivers/power/supply/ipaq_micro_battery.c | 3 |
2 files changed, 4 insertions, 2 deletions
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; |