1 files changed, 35 insertions, 0 deletions

diff --git a/patches/boot_time_opt/0122-locking-rwsem-spin-faster.patch b/patches/boot_time_opt/0122-locking-rwsem-spin-faster.patch
new file mode 100644
index 0000000..b2d76ae
--- /dev/null
+++ b/patches/boot_time_opt/0122-locking-rwsem-spin-faster.patch
@@ -0,0 +1,35 @@
+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 a163542d178e..a2a11ccebb58 100644
+--- a/kernel/locking/rwsem.c
++++ b/kernel/locking/rwsem.c
+@@ -717,6 +717,7 @@ rwsem_spin_on_owner(struct rw_semaphore *sem, unsigned long nonspinnable)
+        struct task_struct *new, *owner;
+        unsigned long flags, new_flags;
+        enum owner_state state;
++       int i = 0;
+ 
+        owner = rwsem_owner_flags(sem, &flags);
+        state = rwsem_owner_state(owner, flags, nonspinnable);
+@@ -750,7 +751,8 @@ rwsem_spin_on_owner(struct rw_semaphore *sem, unsigned long nonspinnable)
+                        break;
+                }
+ 
+-               cpu_relax();
++               if (i++ > 1000)
++                       cpu_relax();
+        }
+        rcu_read_unlock();
+ 
+-- 
+https://clearlinux.org
+