Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Ingo Molnar:
"The tree got pretty big in this development cycle, but the net effect
is pretty good:
115 files changed, 673 insertions(+), 1522 deletions(-)
The main changes were:
- Rework and generalize the mutex code to remove per arch mutex
primitives. (Peter Zijlstra)
- Add vCPU preemption support: add an interface to query the
preemption status of vCPUs and use it in locking primitives - this
optimizes paravirt performance. (Pan Xinhui, Juergen Gross,
Christian Borntraeger)
- Introduce cpu_relax_yield() and remov cpu_relax_lowlatency() to
clean up and improve the s390 lock yielding machinery and its core
kernel impact. (Christian Borntraeger)
- Micro-optimize mutexes some more. (Waiman Long)
- Reluctantly add the to-be-deprecated mutex_trylock_recursive()
interface on a temporary basis, to give the DRM code more time to
get rid of its locking hacks. Any other users will be NAK-ed on
sight. (We turned off the deprecation warning for the time being to
not pollute the build log.) (Peter Zijlstra)
- Improve the rtmutex code a bit, in light of recent long lived
bugs/races. (Thomas Gleixner)
- Misc fixes, cleanups"
* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits)
x86/paravirt: Fix bool return type for PVOP_CALL()
x86/paravirt: Fix native_patch()
locking/ww_mutex: Use relaxed atomics
locking/rtmutex: Explain locking rules for rt_mutex_proxy_unlock()/init_proxy_locked()
locking/rtmutex: Get rid of RT_MUTEX_OWNER_MASKALL
x86/paravirt: Optimize native pv_lock_ops.vcpu_is_preempted()
locking/mutex: Break out of expensive busy-loop on {mutex,rwsem}_spin_on_owner() when owner vCPU is preempted
locking/osq: Break out of spin-wait busy waiting loop for a preempted vCPU in osq_lock()
Documentation/virtual/kvm: Support the vCPU preemption check
x86/xen: Support the vCPU preemption check
x86/kvm: Support the vCPU preemption check
x86/kvm: Support the vCPU preemption check
kvm: Introduce kvm_write_guest_offset_cached()
locking/core, x86/paravirt: Implement vcpu_is_preempted(cpu) for KVM and Xen guests
locking/spinlocks, s390: Implement vcpu_is_preempted(cpu)
locking/core, powerpc: Implement vcpu_is_preempted(cpu)
sched/core: Introduce the vcpu_is_preempted(cpu) interface
sched/wake_q: Rename WAKE_Q to DEFINE_WAKE_Q
locking/core: Provide common cpu_relax_yield() definition
locking/mutex: Don't mark mutex_trylock_recursive() as deprecated, temporarily
...
diff --git a/net/core/dev.c b/net/core/dev.c
index 1d33ce0..3fec23c 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5064,7 +5064,7 @@
return rc;
goto restart;
}
- cpu_relax_lowlatency();
+ cpu_relax();
}
if (napi_poll)
busy_poll_stop(napi, have_poll_lock);