[Xen-devel] [PATCH 0/4] make virt_spin_lock() a pvops function

[Juergen Gross <jgross@xxxxxxxx>]

With virt_spin_lock() being a pvops function the bare metal case can be
optimized by patching the call away completely. In case a kernel running
as a guest it can decide whether to use paravitualized spinlocks, the
current fallback to the unfair test-and-set scheme, or to mimic the
bare metal behavior.

Juergen Gross (4):
  paravirt: add generic _paravirt_false() function
  paravirt: switch vcpu_is_preempted to use _paravirt_false() on bare
    metal
  paravirt: add virt_spin_lock pvops function
  paravirt,xen: correct xen_nopvspin case

 arch/x86/include/asm/paravirt.h       |  5 ++++
 arch/x86/include/asm/paravirt_types.h |  3 +++
 arch/x86/include/asm/qspinlock.h      | 48 ++++++++++++++++++++++++-----------
 arch/x86/kernel/paravirt-spinlocks.c  | 22 ++++++++--------
 arch/x86/kernel/paravirt.c            |  7 +++++
 arch/x86/kernel/paravirt_patch_32.c   | 18 ++++++-------
 arch/x86/kernel/paravirt_patch_64.c   | 17 +++++--------
 arch/x86/kernel/smpboot.c             |  2 ++
 arch/x86/xen/spinlock.c               |  2 ++
 9 files changed, 79 insertions(+), 45 deletions(-)

-- 
2.12.3


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