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author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-12-12 10:48:02 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-12-12 10:48:02 -0800 |
commit | 6cdf89b1ca803b2d2d097466516431b1fc5bf985 (patch) | |
tree | 37c980180dcfdfbed004ae079c7da0fd58b8ecf4 /drivers | |
parent | 3940cf0b3d3c6c5817bb86f61a02277cd33f953a (diff) | |
parent | 11f254dbb3a2e3f0d8552d0dd37f4faa432b6b16 (diff) | |
download | linux-6cdf89b1ca803b2d2d097466516431b1fc5bf985.tar.bz2 |
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
...
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/gpu/drm/i915/i915_gem_request.c | 2 | ||||
-rw-r--r-- | drivers/gpu/drm/i915/i915_gem_shrinker.c | 30 | ||||
-rw-r--r-- | drivers/gpu/drm/msm/msm_gem_shrinker.c | 27 | ||||
-rw-r--r-- | drivers/vhost/net.c | 4 |
4 files changed, 23 insertions, 40 deletions
diff --git a/drivers/gpu/drm/i915/i915_gem_request.c b/drivers/gpu/drm/i915/i915_gem_request.c index 8832f8ec1583..383d13416442 100644 --- a/drivers/gpu/drm/i915/i915_gem_request.c +++ b/drivers/gpu/drm/i915/i915_gem_request.c @@ -723,7 +723,7 @@ bool __i915_spin_request(const struct drm_i915_gem_request *req, if (busywait_stop(timeout_us, cpu)) break; - cpu_relax_lowlatency(); + cpu_relax(); } while (!need_resched()); return false; diff --git a/drivers/gpu/drm/i915/i915_gem_shrinker.c b/drivers/gpu/drm/i915/i915_gem_shrinker.c index 1c237d02f30b..c450076d2f9b 100644 --- a/drivers/gpu/drm/i915/i915_gem_shrinker.c +++ b/drivers/gpu/drm/i915/i915_gem_shrinker.c @@ -35,19 +35,6 @@ #include "i915_drv.h" #include "i915_trace.h" -static bool mutex_is_locked_by(struct mutex *mutex, struct task_struct *task) -{ - if (!mutex_is_locked(mutex)) - return false; - -#if defined(CONFIG_DEBUG_MUTEXES) || defined(CONFIG_MUTEX_SPIN_ON_OWNER) - return mutex->owner == task; -#else - /* Since UP may be pre-empted, we cannot assume that we own the lock */ - return false; -#endif -} - static bool any_vma_pinned(struct drm_i915_gem_object *obj) { struct i915_vma *vma; @@ -240,15 +227,20 @@ unsigned long i915_gem_shrink_all(struct drm_i915_private *dev_priv) static bool i915_gem_shrinker_lock(struct drm_device *dev, bool *unlock) { - if (!mutex_trylock(&dev->struct_mutex)) { - if (!mutex_is_locked_by(&dev->struct_mutex, current)) - return false; + switch (mutex_trylock_recursive(&dev->struct_mutex)) { + case MUTEX_TRYLOCK_FAILED: + return false; - *unlock = false; - } else + case MUTEX_TRYLOCK_SUCCESS: *unlock = true; + return true; - return true; + case MUTEX_TRYLOCK_RECURSIVE: + *unlock = false; + return true; + } + + BUG(); } static unsigned long diff --git a/drivers/gpu/drm/msm/msm_gem_shrinker.c b/drivers/gpu/drm/msm/msm_gem_shrinker.c index 192b2d3a79cb..ab1dd020eb04 100644 --- a/drivers/gpu/drm/msm/msm_gem_shrinker.c +++ b/drivers/gpu/drm/msm/msm_gem_shrinker.c @@ -18,33 +18,24 @@ #include "msm_drv.h" #include "msm_gem.h" -static bool mutex_is_locked_by(struct mutex *mutex, struct task_struct *task) +static bool msm_gem_shrinker_lock(struct drm_device *dev, bool *unlock) { - if (!mutex_is_locked(mutex)) + switch (mutex_trylock_recursive(&dev->struct_mutex)) { + case MUTEX_TRYLOCK_FAILED: return false; -#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_MUTEXES) - return mutex->owner == task; -#else - /* Since UP may be pre-empted, we cannot assume that we own the lock */ - return false; -#endif -} + case MUTEX_TRYLOCK_SUCCESS: + *unlock = true; + return true; -static bool msm_gem_shrinker_lock(struct drm_device *dev, bool *unlock) -{ - if (!mutex_trylock(&dev->struct_mutex)) { - if (!mutex_is_locked_by(&dev->struct_mutex, current)) - return false; + case MUTEX_TRYLOCK_RECURSIVE: *unlock = false; - } else { - *unlock = true; + return true; } - return true; + BUG(); } - static unsigned long msm_gem_shrinker_count(struct shrinker *shrinker, struct shrink_control *sc) { diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index 5dc128a8da83..5dc34653274a 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -342,7 +342,7 @@ static int vhost_net_tx_get_vq_desc(struct vhost_net *net, endtime = busy_clock() + vq->busyloop_timeout; while (vhost_can_busy_poll(vq->dev, endtime) && vhost_vq_avail_empty(vq->dev, vq)) - cpu_relax_lowlatency(); + cpu_relax(); preempt_enable(); r = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov), out_num, in_num, NULL, NULL); @@ -533,7 +533,7 @@ static int vhost_net_rx_peek_head_len(struct vhost_net *net, struct sock *sk) while (vhost_can_busy_poll(&net->dev, endtime) && !sk_has_rx_data(sk) && vhost_vq_avail_empty(&net->dev, vq)) - cpu_relax_lowlatency(); + cpu_relax(); preempt_enable(); |