Commit-ID: f2f09a4cee3507dba0e24b87ba2961a5c377d3a7 Gitweb: http://git.kernel.org/tip/f2f09a4cee3507dba0e24b87ba2961a5c377d3a7 Author: Christian Borntraeger <borntrae...@de.ibm.com> AuthorDate: Tue, 25 Oct 2016 11:03:14 +0200 Committer: Ingo Molnar <mi...@kernel.org> 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 <borntrae...@de.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> Cc: Catalin Marinas <catalin.mari...@arm.com> Cc: Heiko Carstens <heiko.carst...@de.ibm.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Martin Schwidefsky <schwidef...@de.ibm.com> Cc: Nicholas Piggin <npig...@gmail.com> Cc: Noam Camus <no...@ezchip.com> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Russell King <li...@armlinux.org.uk> Cc: Thomas Gleixner <t...@linutronix.de> Cc: Will Deacon <will.dea...@arm.com> Cc: linuxppc-...@lists.ozlabs.org Cc: virtualizat...@lists.linux-foundation.org Cc: xen-de...@lists.xenproject.org Link: http://lkml.kernel.org/r/1477386195-32736-5-git-send-email-borntrae...@de.ibm.com Signed-off-by: Ingo Molnar <mi...@kernel.org> --- 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)
