0121-locking-rwsem-spin-faster.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Arjan van de Ven <arjan@linux.intel.com>
Date: Sun, 18 Feb 2018 23:35:41 +0000
Subject: [PATCH] locking: rwsem: spin faster

tweak rwsem owner spinning a bit
---
 kernel/locking/rwsem.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c
index 69aba4abe104..b4818ccad5de 100644
--- a/kernel/locking/rwsem.c
+++ b/kernel/locking/rwsem.c
@@ -707,6 +707,7 @@ rwsem_spin_on_owner(struct rw_semaphore *sem)
 	struct task_struct *new, *owner;
 	unsigned long flags, new_flags;
 	enum owner_state state;
+	int i = 0;
 
 	lockdep_assert_preemption_disabled();
 
@@ -743,7 +744,8 @@ rwsem_spin_on_owner(struct rw_semaphore *sem)
 			break;
 		}
 
-		cpu_relax();
+		if (i++ > 1000)
+			cpu_relax();
 	}
 
 	return state;
-- 
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