[RT PATCH] locking/rwsem-rt: Remove might_sleep() in __up_read()

From: Andrew Halaney
Date: Tue Apr 06 2021 - 18:22:01 EST


There's no chance of sleeping here, the reader is giving up the
lock and possibly waking up the writer who is waiting on it.

Reported-by: Chunyu Hu <chuhu@xxxxxxxxxx>
Signed-off-by: Andrew Halaney <ahalaney@xxxxxxxxxx>
---
Hello,

I ran into a warning caused by this, and I think the warning is
incorrect. Please let me know if I'm wrong!
I'm working off of linux-5.12.y-rt, but this applies cleanly to older
stable branches as well.

Thanks,
Andrew

kernel/locking/rwsem-rt.c | 1 -
1 file changed, 1 deletion(-)

diff --git a/kernel/locking/rwsem-rt.c b/kernel/locking/rwsem-rt.c
index 274172d5bb3a..b61edc4dcb73 100644
--- a/kernel/locking/rwsem-rt.c
+++ b/kernel/locking/rwsem-rt.c
@@ -198,7 +198,6 @@ void __up_read(struct rw_semaphore *sem)
if (!atomic_dec_and_test(&sem->readers))
return;

- might_sleep();
raw_spin_lock_irq(&m->wait_lock);
/*
* Wake the writer, i.e. the rtmutex owner. It might release the
--
2.30.2