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-rw-r--r--patches/boot_time_opt_guest/0105-locking-rwsem-spin-faster.patch35
1 files changed, 35 insertions, 0 deletions
diff --git a/patches/boot_time_opt_guest/0105-locking-rwsem-spin-faster.patch b/patches/boot_time_opt_guest/0105-locking-rwsem-spin-faster.patch
new file mode 100644
index 0000000..502064e
--- /dev/null
+++ b/patches/boot_time_opt_guest/0105-locking-rwsem-spin-faster.patch
@@ -0,0 +1,35 @@
1From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
2From: Arjan van de Ven <arjan@linux.intel.com>
3Date: Sun, 18 Feb 2018 23:35:41 +0000
4Subject: [PATCH] locking: rwsem: spin faster
5
6tweak rwsem owner spinning a bit
7---
8 kernel/locking/rwsem.c | 4 +++-
9 1 file changed, 3 insertions(+), 1 deletion(-)
10
11diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c
12index f11b9bd3431d..1bbfcc1e0474 100644
13--- a/kernel/locking/rwsem.c
14+++ b/kernel/locking/rwsem.c
15@@ -717,6 +717,7 @@ rwsem_spin_on_owner(struct rw_semaphore *sem, unsigned long nonspinnable)
16 struct task_struct *new, *owner;
17 unsigned long flags, new_flags;
18 enum owner_state state;
19+ int i = 0;
20
21 owner = rwsem_owner_flags(sem, &flags);
22 state = rwsem_owner_state(owner, flags, nonspinnable);
23@@ -750,7 +751,8 @@ rwsem_spin_on_owner(struct rw_semaphore *sem, unsigned long nonspinnable)
24 break;
25 }
26
27- cpu_relax();
28+ if (i++ > 1000)
29+ cpu_relax();
30 }
31 rcu_read_unlock();
32
33--
34https://clearlinux.org
35