diff mbox series

[v3,3/7] asm-generic: qrwlock: Document the spinlock fairness requirements

Message ID 20220414220214.24556-4-palmer@rivosinc.com (mailing list archive)
State New, archived
Headers show
Series Generic Ticket Spinlocks | expand

Commit Message

Palmer Dabbelt April 14, 2022, 10:02 p.m. UTC 
From: Palmer Dabbelt <palmer@rivosinc.com>

I could only find the fairness requirements documented as the C code,
this calls them out in a comment just to be a bit more explicit.

Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
---
 include/asm-generic/qrwlock.h | 4 ++++
 1 file changed, 4 insertions(+)
diff mbox series

Patch

diff --git a/include/asm-generic/qrwlock.h b/include/asm-generic/qrwlock.h
index 7ae0ece07b4e..24ae09c1db9f 100644
--- a/include/asm-generic/qrwlock.h
+++ b/include/asm-generic/qrwlock.h
@@ -2,6 +2,10 @@ 
 /*
  * Queue read/write lock
  *
+ * These use generic atomic and locking routines, but depend on a fair spinlock
+ * implementation in order to be fair themselves.  The implementation in
+ * asm-generic/spinlock.h meets these requirements.
+ *
  * (C) Copyright 2013-2014 Hewlett-Packard Development Company, L.P.
  *
  * Authors: Waiman Long <waiman.long@hp.com>