[PATCH v5 05/11] PM / QoS: Teach lockdep about dev_pm_qos_mtx locking order
From: Rob Clark
Date: Tue Aug 22 2023 - 14:02:50 EST
From: Rob Clark <robdclark@xxxxxxxxxxxx>
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@xxxxxxxxxxxx>
---
drivers/base/power/qos.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/drivers/base/power/qos.c b/drivers/base/power/qos.c
index 09834f3354d7..2018c805a6f1 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);
--
2.41.0