On Thu, 12 Mar 2026 05:48:04 -0400 lirongqing wrote:
quoted
During device hot-unplug, the mlx5 driver expects quickly unregister
notification chains. The standard atomic_notifier_chain_unregister()
calls synchronize_rcu(), which introduces significant latency and can
become a bottleneck during mass resource cleanup.
Introduce atomic_notifier_chain_unregister_expedited() to leverage
synchronize_rcu_expedited(), and use it significantly reducing wait
times in the following paths:
- Event Queue (EQ) notifier chain
- Firmware event notifier chain
- IRQ notifier chain
This acceleration ensures faster teardown during hot-unplug events.
Some detailed example and how long the whole operation takes would be great
in the commit msg.
OK, I will add in v2
quoted
/**
+ * atomic_notifier_chain_unregister_expedited - Remove notifier from an
atomic notifier chain
quoted
+ * @nh: Pointer to head of the atomic notifier chain
+ * @n: Entry to remove from notifier chain
+ *
+ * Removes a notifier from an atomic notifier chain and forcefully
+ * accelerates the RCU grace period.
+ *
+ * Returns zero on success or %-ENOENT on failure.
Warning: kernel/notifier.c:211 No description found for return value of
'atomic_notifier_chain_unregister_expedited'
kdoc wants you to use Return: or Returns: the colon is how it knows this is the
doc for return value not just a random mention of the word Returns
--
I will fix this in v2
Thank you
[Li,Rongqing]
pw-bot: cr