[tip:locking/core] locking/core: Remove cpu_relax_lowlatency() users
From: tip-bot for Christian Borntraeger
Date: Wed Nov 16 2016 - 07:11:18 EST
Commit-ID: f2f09a4cee3507dba0e24b87ba2961a5c377d3a7
Gitweb: http://git.kernel.org/tip/f2f09a4cee3507dba0e24b87ba2961a5c377d3a7
Author: Christian Borntraeger <borntraeger@xxxxxxxxxx>
AuthorDate: Tue, 25 Oct 2016 11:03:14 +0200
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Wed, 16 Nov 2016 10:15:10 +0100
locking/core: Remove cpu_relax_lowlatency() users
With the s390 special case of a yielding cpu_relax() implementation gone,
we can now remove all users of cpu_relax_lowlatency() and replace them
with cpu_relax().
Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
Cc: Nicholas Piggin <npiggin@xxxxxxxxx>
Cc: Noam Camus <noamc@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Russell King <linux@xxxxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Cc: linuxppc-dev@xxxxxxxxxxxxxxxx
Cc: virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
Cc: xen-devel@xxxxxxxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/1477386195-32736-5-git-send-email-borntraeger@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
drivers/gpu/drm/i915/i915_gem_request.c | 2 +-
drivers/vhost/net.c | 4 ++--
kernel/locking/mcs_spinlock.h | 4 ++--
kernel/locking/mutex.c | 4 ++--
kernel/locking/osq_lock.c | 6 +++---
kernel/locking/qrwlock.c | 6 +++---
kernel/locking/rwsem-xadd.c | 4 ++--
lib/lockref.c | 2 +-
8 files changed, 16 insertions(+), 16 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_gem_request.c b/drivers/gpu/drm/i915/i915_gem_request.c
index 8832f8e..383d134 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/vhost/net.c b/drivers/vhost/net.c
index 5dc128a..5dc3465 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();
diff --git a/kernel/locking/mcs_spinlock.h b/kernel/locking/mcs_spinlock.h
index c835270..6a385aa 100644
--- a/kernel/locking/mcs_spinlock.h
+++ b/kernel/locking/mcs_spinlock.h
@@ -28,7 +28,7 @@ struct mcs_spinlock {
#define arch_mcs_spin_lock_contended(l) \
do { \
while (!(smp_load_acquire(l))) \
- cpu_relax_lowlatency(); \
+ cpu_relax(); \
} while (0)
#endif
@@ -108,7 +108,7 @@ void mcs_spin_unlock(struct mcs_spinlock **lock, struct mcs_spinlock *node)
return;
/* Wait until the next pointer is set */
while (!(next = READ_ONCE(node->next)))
- cpu_relax_lowlatency();
+ cpu_relax();
}
/* Pass lock to next waiter. */
diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c
index 17a88e9..a65e09a 100644
--- a/kernel/locking/mutex.c
+++ b/kernel/locking/mutex.c
@@ -369,7 +369,7 @@ bool mutex_spin_on_owner(struct mutex *lock, struct task_struct *owner)
break;
}
- cpu_relax_lowlatency();
+ cpu_relax();
}
rcu_read_unlock();
@@ -492,7 +492,7 @@ static bool mutex_optimistic_spin(struct mutex *lock,
* memory barriers as we'll eventually observe the right
* values at the cost of a few extra spins.
*/
- cpu_relax_lowlatency();
+ cpu_relax();
}
if (!waiter)
diff --git a/kernel/locking/osq_lock.c b/kernel/locking/osq_lock.c
index 05a3785..4ea2710 100644
--- a/kernel/locking/osq_lock.c
+++ b/kernel/locking/osq_lock.c
@@ -75,7 +75,7 @@ osq_wait_next(struct optimistic_spin_queue *lock,
break;
}
- cpu_relax_lowlatency();
+ cpu_relax();
}
return next;
@@ -122,7 +122,7 @@ bool osq_lock(struct optimistic_spin_queue *lock)
if (need_resched())
goto unqueue;
- cpu_relax_lowlatency();
+ cpu_relax();
}
return true;
@@ -148,7 +148,7 @@ unqueue:
if (smp_load_acquire(&node->locked))
return true;
- cpu_relax_lowlatency();
+ cpu_relax();
/*
* Or we race against a concurrent unqueue()'s step-B, in which
diff --git a/kernel/locking/qrwlock.c b/kernel/locking/qrwlock.c
index 19248dd..cc3ed0c 100644
--- a/kernel/locking/qrwlock.c
+++ b/kernel/locking/qrwlock.c
@@ -54,7 +54,7 @@ static __always_inline void
rspin_until_writer_unlock(struct qrwlock *lock, u32 cnts)
{
while ((cnts & _QW_WMASK) == _QW_LOCKED) {
- cpu_relax_lowlatency();
+ cpu_relax();
cnts = atomic_read_acquire(&lock->cnts);
}
}
@@ -130,7 +130,7 @@ void queued_write_lock_slowpath(struct qrwlock *lock)
(cmpxchg_relaxed(&l->wmode, 0, _QW_WAITING) == 0))
break;
- cpu_relax_lowlatency();
+ cpu_relax();
}
/* When no more readers, set the locked flag */
@@ -141,7 +141,7 @@ void queued_write_lock_slowpath(struct qrwlock *lock)
_QW_LOCKED) == _QW_WAITING))
break;
- cpu_relax_lowlatency();
+ cpu_relax();
}
unlock:
arch_spin_unlock(&lock->wait_lock);
diff --git a/kernel/locking/rwsem-xadd.c b/kernel/locking/rwsem-xadd.c
index 2337b4b..2fa2e2e6 100644
--- a/kernel/locking/rwsem-xadd.c
+++ b/kernel/locking/rwsem-xadd.c
@@ -368,7 +368,7 @@ static noinline bool rwsem_spin_on_owner(struct rw_semaphore *sem)
return false;
}
- cpu_relax_lowlatency();
+ cpu_relax();
}
rcu_read_unlock();
out:
@@ -423,7 +423,7 @@ static bool rwsem_optimistic_spin(struct rw_semaphore *sem)
* memory barriers as we'll eventually observe the right
* values at the cost of a few extra spins.
*/
- cpu_relax_lowlatency();
+ cpu_relax();
}
osq_unlock(&sem->osq);
done:
diff --git a/lib/lockref.c b/lib/lockref.c
index 5a92189..c4bfcb8 100644
--- a/lib/lockref.c
+++ b/lib/lockref.c
@@ -20,7 +20,7 @@
if (likely(old.lock_count == prev.lock_count)) { \
SUCCESS; \
} \
- cpu_relax_lowlatency(); \
+ cpu_relax(); \
} \
} while (0)