search for: unqueue

...ll locks you change with this. Thanks, Davidlohr > * vcpu_is_preempted is a macro defined by false if >+ * arch does not support vcpu preempted check, > */ >- if (need_resched()) >+ if (need_resched() || vcpu_is_preempted(node_cpu(node->prev))) > goto unqueue; > > cpu_relax_lowlatency(); >-- >2.4.11 >

...ll locks you change with this. Thanks, Davidlohr > * vcpu_is_preempted is a macro defined by false if >+ * arch does not support vcpu preempted check, > */ >- if (need_resched()) >+ if (need_resched() || vcpu_is_preempted(node_cpu(node->prev))) > goto unqueue; > > cpu_relax_lowlatency(); >-- >2.4.11 >

...ing/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 @@ bool osq_lock(struct optimistic_spin_queue *lock) if (smp_load_acquire(&node->locked)) return true; - cpu_relax_lowlatency(); + cpu_relax(); /* * Or we race against a concurrent unqueue...

...> what it means. > > Could you help a bit in explaining it in English please? (refer to the state diagram, if we count states left->right, top->bottom, then this is: 5->2 or 7->8 n,0 -> 0,1: the lock is free and the tail points to the first queued; this means that unqueueing implies wiping the tail, at the same time, acquire the lock. *,0 -> *,1: the lock is free and the tail doesn't point to the first queued; this means that unqueueing doesn't touch the tail pointer but only sets the lock. > > + > > + old = atomic_cmpxchg(&am...

...n block. + * Use vcpu_is_preempted to detech lock holder preemption issue + * and break. vcpu_is_preempted is a macro defined by false if + * arch does not support vcpu preempted check, */ - if (need_resched()) + if (need_resched() || vcpu_is_preempted(node_cpu(node->prev))) goto unqueue; cpu_relax_lowlatency(); -- 2.4.11

On Sun, Jun 15, 2014 at 02:46:58PM +0200, Peter Zijlstra wrote: > From: Waiman Long <Waiman.Long at hp.com> > > This patch introduces a new generic queue spinlock implementation that > can serve as an alternative to the default ticket spinlock. Compared > with the ticket spinlock, this queue spinlock should be almost as fair > as the ticket spinlock. It has about the same

On Sun, Jun 15, 2014 at 02:46:58PM +0200, Peter Zijlstra wrote: > From: Waiman Long <Waiman.Long at hp.com> > > This patch introduces a new generic queue spinlock implementation that > can serve as an alternative to the default ticket spinlock. Compared > with the ticket spinlock, this queue spinlock should be almost as fair > as the ticket spinlock. It has about the same

I figure this group will know better than any other I have contact with, is 700-800 I/Ops reasonable for a 7200 RPM SATA drive (1 TB Sun badged Seagate ST31000N in a J4400) ? I have a resilver running and am seeing about 700-800 writes/sec. on the hot spare as it resilvers. There is no other I/O activity on this box, as this is a remote replication target for production data. I have a the

change from v2: no code change, fix typos, update some comments change from v1: a simplier definition of default vcpu_is_preempted skip mahcine type check on ppc, and add config. remove dedicated macro. add one patch to drop overload of rwsem_spin_on_owner and mutex_spin_on_owner. add more comments thanks boqun and Peter's suggestion. This patch set aims to fix lock holder preemption

change from v2: no code change, fix typos, update some comments change from v1: a simplier definition of default vcpu_is_preempted skip mahcine type check on ppc, and add config. remove dedicated macro. add one patch to drop overload of rwsem_spin_on_owner and mutex_spin_on_owner. add more comments thanks boqun and Peter's suggestion. This patch set aims to fix lock holder preemption

...st_async and return it in read request. server: Close async wait handle when wait is satisfied. server: Return async result directly instead of via APCs if it's available. server: Use create_request_async for write requests. server: Store fd reference in async object for unqueued asyncs. server: Allow async_handoff users to set result themselves. ntdll: Set iosb status in server_ioctl_file. server: Use create_request_async in ioctl request handler. server: Use create_request_async in flush request handler. server: Remove no longer needed need_...

change from v5: spilt x86/kvm patch into guest/host part. introduce kvm_write_guest_offset_cached. fix some typos. rebase patch onto 4.9.2 change from v4: spilt x86 kvm vcpu preempted check into two patches. add documentation patch. add x86 vcpu preempted check patch under xen add s390 vcpu preempted check patch change from v3: add x86 vcpu preempted check patch change from v2: no code

change from v5: spilt x86/kvm patch into guest/host part. introduce kvm_write_guest_offset_cached. fix some typos. rebase patch onto 4.9.2 change from v4: spilt x86 kvm vcpu preempted check into two patches. add documentation patch. add x86 vcpu preempted check patch under xen add s390 vcpu preempted check patch change from v3: add x86 vcpu preempted check patch change from v2: no code

change fomr v1: a simplier definition of default vcpu_is_preempted skip mahcine type check on ppc, and add config. remove dedicated macro. add one patch to drop overload of rwsem_spin_on_owner and mutex_spin_on_owner. add more comments thanks boqun and Peter's suggestion. This patch set aims to fix lock holder preemption issues. test-case: perf record -a perf bench sched messaging -g

change fomr v1: a simplier definition of default vcpu_is_preempted skip mahcine type check on ppc, and add config. remove dedicated macro. add one patch to drop overload of rwsem_spin_on_owner and mutex_spin_on_owner. add more comments thanks boqun and Peter's suggestion. This patch set aims to fix lock holder preemption issues. test-case: perf record -a perf bench sched messaging -g

Peter, here is v2 with some improved patch descriptions and some fixes. The previous version has survived one day of linux-next and I only changed small parts. So unless there is some other issue, feel free to pull (or to apply the patches) to tip/locking. The following changes since commit 07d9a380680d1c0eb51ef87ff2eab5c994949e69: Linux 4.9-rc2 (2016-10-23 17:10:14 -0700) are available in

Peter, here is v2 with some improved patch descriptions and some fixes. The previous version has survived one day of linux-next and I only changed small parts. So unless there is some other issue, feel free to pull (or to apply the patches) to tip/locking. The following changes since commit 07d9a380680d1c0eb51ef87ff2eab5c994949e69: Linux 4.9-rc2 (2016-10-23 17:10:14 -0700) are available in

...xt) +{ + ASSERT(context); + if (atomic_dec_and_test(&context->refCount)) + ctx_free_ctx(context); +} + +/* + * Dequeues the next datagram and returns it to caller. + * The caller passes in a pointer to the max size datagram + * it can handle and the datagram is only unqueued if the + * size is less than maxSize. If larger maxSize is set to + * the size of the datagram to give the caller a chance to + * set up a larger buffer for the guestcall. + */ +int vmci_ctx_dequeue_datagram(struct vmci_ctx *context, + size_t *maxSize, +...

...xt) +{ + ASSERT(context); + if (atomic_dec_and_test(&context->refCount)) + ctx_free_ctx(context); +} + +/* + * Dequeues the next datagram and returns it to caller. + * The caller passes in a pointer to the max size datagram + * it can handle and the datagram is only unqueued if the + * size is less than maxSize. If larger maxSize is set to + * the size of the datagram to give the caller a chance to + * set up a larger buffer for the guestcall. + */ +int vmci_ctx_dequeue_datagram(struct vmci_ctx *context, + size_t *maxSize, +...

change from v4: spilt x86 kvm vcpu preempted check into two patches. add documentation patch. add x86 vcpu preempted check patch under xen add s390 vcpu preempted check patch change from v3: add x86 vcpu preempted check patch change from v2: no code change, fix typos, update some comments change from v1: a simplier definition of default vcpu_is_preempted skip mahcine type check on ppc,