From 6f4024c162ccefcf0eb04ec8bac8d9e8611037d6 Mon Sep 17 00:00:00 2001
From: Jiri Slaby <jslaby@suse.cz>
Date: May 17 2023 19:16:04 +0000
Subject: locking/rwsem: Add __always_inline annotation to

__down_read_common() and inlined callers (bsc#1012628).

---

diff --git a/patches.kernel.org/6.3.3-225-locking-rwsem-Add-__always_inline-annotation-to.patch b/patches.kernel.org/6.3.3-225-locking-rwsem-Add-__always_inline-annotation-to.patch
new file mode 100644
index 0000000..bbf77b7
--- /dev/null
+++ b/patches.kernel.org/6.3.3-225-locking-rwsem-Add-__always_inline-annotation-to.patch
@@ -0,0 +1,71 @@
+From: John Stultz <jstultz@google.com>
+Date: Wed, 3 May 2023 02:33:51 +0000
+Subject: [PATCH] locking/rwsem: Add __always_inline annotation to
+ __down_read_common() and inlined callers
+References: bsc#1012628
+Patch-mainline: 6.3.3
+Git-commit: 92cc5d00a431e96e5a49c0b97e5ad4fa7536bd4b
+
+commit 92cc5d00a431e96e5a49c0b97e5ad4fa7536bd4b upstream.
+
+Apparently despite it being marked inline, the compiler
+may not inline __down_read_common() which makes it difficult
+to identify the cause of lock contention, as the blocked
+function in traceevents will always be listed as
+__down_read_common().
+
+So this patch adds __always_inline annotation to the common
+function (as well as the inlined helper callers) to force it to
+be inlined so the blocking function will be listed (via Wchan)
+in traceevents.
+
+Fixes: c995e638ccbb ("locking/rwsem: Fold __down_{read,write}*()")
+Reported-by: Tim Murray <timmurray@google.com>
+Signed-off-by: John Stultz <jstultz@google.com>
+Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
+Reviewed-by: Waiman Long <longman@redhat.com>
+Cc: stable@vger.kernel.org
+Link: https://lkml.kernel.org/r/20230503023351.2832796-1-jstultz@google.com
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+Signed-off-by: Jiri Slaby <jslaby@suse.cz>
+---
+ kernel/locking/rwsem.c | 8 ++++----
+ 1 file changed, 4 insertions(+), 4 deletions(-)
+
+diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c
+index acb5a503..9eabd585 100644
+--- a/kernel/locking/rwsem.c
++++ b/kernel/locking/rwsem.c
+@@ -1240,7 +1240,7 @@ static struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem)
+ /*
+  * lock for reading
+  */
+-static inline int __down_read_common(struct rw_semaphore *sem, int state)
++static __always_inline int __down_read_common(struct rw_semaphore *sem, int state)
+ {
+ 	int ret = 0;
+ 	long count;
+@@ -1258,17 +1258,17 @@ static inline int __down_read_common(struct rw_semaphore *sem, int state)
+ 	return ret;
+ }
+ 
+-static inline void __down_read(struct rw_semaphore *sem)
++static __always_inline void __down_read(struct rw_semaphore *sem)
+ {
+ 	__down_read_common(sem, TASK_UNINTERRUPTIBLE);
+ }
+ 
+-static inline int __down_read_interruptible(struct rw_semaphore *sem)
++static __always_inline int __down_read_interruptible(struct rw_semaphore *sem)
+ {
+ 	return __down_read_common(sem, TASK_INTERRUPTIBLE);
+ }
+ 
+-static inline int __down_read_killable(struct rw_semaphore *sem)
++static __always_inline int __down_read_killable(struct rw_semaphore *sem)
+ {
+ 	return __down_read_common(sem, TASK_KILLABLE);
+ }
+-- 
+2.35.3
+
diff --git a/series.conf b/series.conf
index 49790f6..8662022 100644
--- a/series.conf
+++ b/series.conf
@@ -958,6 +958,7 @@
 	patches.kernel.org/6.3.3-222-drm-amd-display-Lowering-min-Z8-residency-time.patch
 	patches.kernel.org/6.3.3-223-parisc-Fix-encoding-of-swp_entry-due-to-added-S.patch
 	patches.kernel.org/6.3.3-224-perf-x86-Fix-missing-sample-size-update-on-AMD-.patch
+	patches.kernel.org/6.3.3-225-locking-rwsem-Add-__always_inline-annotation-to.patch
 
 	########################################################
 	# Build fixes that apply to the vanilla kernel too.