US 2017/0286187 A1 · ADAPTIVE QUEUED LOCKING FOR CONTROL OF SPECULATIVE EXECUTION

Abstract

Adaptive queued locking for control of speculative execution is disclosed. An example apparatus includes a queue controller to control removal of threads from a queue that contains threads waiting to be permitted to speculatively execute in a critical section of a multi-threaded program. The apparatus also includes a first thread associated with a head node of the queue. The queue controller controls the removal of threads from the queue in response to operations performed by the first thread. In addition, an adjuster to change a number of threads permitted to speculatively execute based on a rate of threads currently speculatively executing transactions in the critical section is included.

Claims20

Dependent claims

An apparatus, comprising:

a queue controller to control a removal of threads from a queue, the queue to contain threads that are waiting to be permitted to speculatively execute in a critical section of a multi-threaded program;
a first thread associated with a head node of the queue, the queue controller to control the removal of threads from the queue in response to operations performed by the first thread;
and
an adjuster to change a number of threads permitted to speculatively execute based on a rate of threads currently speculatively executing transactions in the critical section, the adjuster is implemented via a logic circuit.

1 more element

A method, comprising:

comparing, by executing an instruction with at least one processor, a current quota to a thread count, the thread count corresponding to a first number of threads currently speculatively executing in a critical section of a multi-threaded program, the current quota corresponding to a second number of threads permitted to speculatively execute in the critical section after being in a queue, and the queue identifying threads that are waiting to be permitted to speculatively execute in the critical section, the first thread being one of a plurality of threads of the multi-threaded program and the first thread corresponding to a head node of the queue;
based on the comparison of the current quota to the thread count, controlling, by executing an instruction with the at least one processor, removal of threads from the queue;
and
based on the comparison of the current quota to the thread count, adjusting, by executing an instruction with the at least one of processor, the current quota.

1 more element

At least one tangible computer readable storage medium comprising instructions that, when executed, cause at least one machine to at least:

populate a queue with a list of threads that experienced a memory access conflict while executing in the critical section of a multi-threaded program, the threads in the queue corresponding to nodes of the queue, and a first thread in the queue corresponding to a head node;
compare a current quota to a thread count, the thread count corresponding to a first number of threads currently speculatively executing in a critical section of a multi-threaded program, the current quota corresponding to a second number of threads permitted to speculatively execute in the critical section after being in the queue;
and
based on the comparison of the current quota to the thread count, adjust the current quota.

1 more element

Dependencies are inferred from the claim text.

Facts

Application

15/631,913Filed 23 Jun 2017

Priority

3 Jun 2015

Published

5 Oct 2017

Term ends

Not estimatedThe source records don’t support an estimate.

Classification12 codes

G06F 9/528
Mutual exclusion algorithms: by using speculative mechanisms
G06F 9/467
Transaction processing: transactional memory
G06F 9/48
Multiprogramming arrangements: program initiating; Program switching, e.g. by interrupt
G06F 9/4881
By program, e.g. task dispatcher, supervisor, operating system: scheduling strategies for dispatcher, e.g. round robin, multi-level priority queues

Adaptive queued locking for control of speculative execution

Life of this patent

Adaptive queued locking for control of speculative execution

Life of this patent

Abstract

Claims20