Re: [PATCH v3 0/2] guard virt_spin_lock() with a static key
From: Juergen Gross
Date: Mon Sep 25 2017 - 09:59:24 EST
Ping?
On 06/09/17 19:36, Juergen Gross wrote:
> With virt_spin_lock() being guarded by a static key 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.
>
> V3:
> - remove test for hypervisor environment from virt_spin_lock(9 as
> suggested by Waiman Long
>
> V2:
> - use static key instead of making virt_spin_lock() a pvops function
>
> Juergen Gross (2):
> paravirt/locks: use new static key for controlling call of
> virt_spin_lock()
> paravirt,xen: correct xen_nopvspin case
>
> arch/x86/include/asm/qspinlock.h | 11 ++++++++++-
> arch/x86/kernel/paravirt-spinlocks.c | 6 ++++++
> arch/x86/kernel/smpboot.c | 2 ++
> arch/x86/xen/spinlock.c | 2 ++
> kernel/locking/qspinlock.c | 4 ++++
> 5 files changed, 24 insertions(+), 1 deletion(-)
>