diff mbox series

[v4,5/9] PM / QoS: Teach lockdep about dev_pm_qos_mtx locking order

Message ID 20230807171148.210181-6-robdclark@gmail.com
State Superseded
Headers show
Series drm/msm+PM+icc: Make job_run() reclaim-safe | expand

Commit Message

Rob Clark Aug. 7, 2023, 5:11 p.m. UTC 
From: Rob Clark <robdclark@chromium.org>

Annotate dev_pm_qos_mtx to teach lockdep to scream about allocations
that could trigger reclaim under dev_pm_qos_mtx.

Signed-off-by: Rob Clark <robdclark@chromium.org>
---
 drivers/base/power/qos.c | 11 +++++++++++
 1 file changed, 11 insertions(+)
diff mbox series

Patch

diff --git a/drivers/base/power/qos.c b/drivers/base/power/qos.c
index 5ec06585b6d1..63cb1086f195 100644
--- a/drivers/base/power/qos.c
+++ b/drivers/base/power/qos.c
@@ -1017,3 +1017,14 @@  void dev_pm_qos_hide_latency_tolerance(struct device *dev)
 	pm_runtime_put(dev);
 }
 EXPORT_SYMBOL_GPL(dev_pm_qos_hide_latency_tolerance);
+
+static int __init dev_pm_qos_init(void)
+{
+	/* Teach lockdep about lock ordering wrt. shrinker: */
+	fs_reclaim_acquire(GFP_KERNEL);
+	might_lock(&dev_pm_qos_mtx);
+	fs_reclaim_release(GFP_KERNEL);
+
+	return 0;
+}
+early_initcall(dev_pm_qos_init);