From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Wed, 4 Sep 2013 18:55:10 +0000 (-0700)
Subject: Merge branch 'x86-spinlocks-for-linus' of git://git.kernel.org/pub/scm/linux/kernel... 
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=816434ec4a67;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git

Merge branch 'x86-spinlocks-for-linus' of git://git./linux/kernel/git/tip/tip

Pull x86 spinlock changes from Ingo Molnar:
 "The biggest change here are paravirtualized ticket spinlocks (PV
  spinlocks), which bring a nice speedup on various benchmarks.

  The KVM host side will come to you via the KVM tree"

* 'x86-spinlocks-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/kvm/guest: Fix sparse warning: "symbol 'klock_waiting' was not declared as static"
  kvm: Paravirtual ticketlocks support for linux guests running on KVM hypervisor
  kvm guest: Add configuration support to enable debug information for KVM Guests
  kvm uapi: Add KICK_CPU and PV_UNHALT definition to uapi
  xen, pvticketlock: Allow interrupts to be enabled while blocking
  x86, ticketlock: Add slowpath logic
  jump_label: Split jumplabel ratelimit
  x86, pvticketlock: When paravirtualizing ticket locks, increment by 2
  x86, pvticketlock: Use callee-save for lock_spinning
  xen, pvticketlocks: Add xen_nopvspin parameter to disable xen pv ticketlocks
  xen, pvticketlock: Xen implementation for PV ticket locks
  xen: Defer spinlock setup until boot CPU setup
  x86, ticketlock: Collapse a layer of functions
  x86, ticketlock: Don't inline _spin_unlock when using paravirt spinlocks
  x86, spinlock: Replace pv spinlocks with pv ticketlocks
---

816434ec4a674fcdb3c2221a6dffdc8f34020550
diff --cc arch/x86/include/asm/spinlock.h
index e0e668422c75,d68883dd133c..bf156ded74b5
--- a/arch/x86/include/asm/spinlock.h
+++ b/arch/x86/include/asm/spinlock.h
@@@ -34,11 -37,31 +37,36 @@@
  # define UNLOCK_LOCK_PREFIX
  #endif
  
+ /* How long a lock should spin before we consider blocking */
+ #define SPIN_THRESHOLD	(1 << 15)
+ 
+ extern struct static_key paravirt_ticketlocks_enabled;
+ static __always_inline bool static_key_false(struct static_key *key);
+ 
+ #ifdef CONFIG_PARAVIRT_SPINLOCKS
+ 
+ static inline void __ticket_enter_slowpath(arch_spinlock_t *lock)
+ {
+ 	set_bit(0, (volatile unsigned long *)&lock->tickets.tail);
+ }
+ 
+ #else  /* !CONFIG_PARAVIRT_SPINLOCKS */
+ static __always_inline void __ticket_lock_spinning(arch_spinlock_t *lock,
+ 							__ticket_t ticket)
+ {
+ }
+ static inline void __ticket_unlock_kick(arch_spinlock_t *lock,
+ 							__ticket_t ticket)
+ {
+ }
+ 
+ #endif /* CONFIG_PARAVIRT_SPINLOCKS */
+ 
 +static __always_inline int arch_spin_value_unlocked(arch_spinlock_t lock)
 +{
 +	return lock.tickets.head == lock.tickets.tail;
 +}
 +
  /*
   * Ticket locks are conceptually two parts, one indicating the current head of
   * the queue, and the other indicating the current tail. The lock is acquired