International Business Machines Corporation

Gary M King

Peter Bergersen Yocom

Donald W Schmidt

Daniel V Rosa

Catherine Krueger Eilert

Jeffrey Mark Nick

Jeffrey Paul Kubala

Jeffrey David Aman

Jonathan D Bradbury

David Harold Surman

Jane Helen Bartik

Ansu A Abraham

Harry M Yudenfriend

William J Rooney

Steven N Goss

Michael J Jordan

Bernard R Pierce

Georgette L Kurdt

Kelly B Pushong

Karl J Duvalsaint

Wendell W Wilkinson

Catherine Mary Moxey

Kevin F Smith

Francis E Johnson

Kenneth Glenn Rothwell

Kelly Scott Carpenter

John Charles Nagy

Aaron Ortiz Araujo

Terence A Ford

Clarisse A Taaffe-Hedglin

Daniel A Kaberon

Embodiments relate tracking utilization in a multithreading (MT) computer system. According to one aspect, a computer system includes a configuration with a core configured to operate in a MT that supports multiple threads on shared resources of the core. The core is configured to perform a method that includes resetting a plurality of utilization counters. The utilization counters include a plurality of sets of counters. During each clock cycle on the core, a set of counters is selected from the plurality of sets of counters. The selecting is based on a number of currently active threads on the core. In addition, during each clock cycle a counter in the selected set of counters is incremented based on an aggregation of one or more execution events at the multiple threads of the core. Values of the utilization counters are provided to a software program.

Hardware counters to track utilization in a multithreading computer system

A technique for simultaneous multithreading (SMT) by a computer is provided. An operating system or a second-level hypervisor of the computer manages a logical core configuration for simultaneous multithreading. The operating system or the second-level hypervisor has control over a logical core and control over logical threads on the logical core. The operating system or the second-level hypervisor of the computer configures a host hypervisor to assign an entirety of the logical core to a single physical core, such that one logical core executes per physical core. The logical core is run on the single physical core on an exclusive basis for a period of time, such that the logical threads of the logical core execute on physical threads of the single physical core.

Runtime capacity planning in a simultaneous multithreading (SMT) environment

A method for client workload characterization in a zSeries benchmark center environment. The method includes collecting client characterization data (CCCD). The method concludes with calibrating a large system performance reference (LSPR) relative to the client characterization data.

Method for client workload characterization in a zSeries benchmark center environment

A technique for chargeback with simultaneous multithreading (SMT) by a computer is provided. One or more of an operating system and a second-level hypervisor of the computer manage a logical core configuration for simultaneous multithreading, the operating system and/or the second-level hypervisor has control over a logical core and control over logical threads on the logical core. The operating system and/or the second-level hypervisor is configures a host hypervisor to assign an entirety of the logical core to a single physical core, such that one logical core executes per physical core. The logical core is run on the single physical core on an exclusive basis for a period of time, such that the logical threads of the logical core execute on physical threads of the single physical core. A capacity use time is determined for each of the logical threads executing on the physical threads of the single physical core.

Runtime chargeback in a simultaneous multithreading (SMT) environment

The configuration of the logical processors of a logical partition is managed dynamically. A logical partition is initially configured with one or more logical processors. Thereafter, the configuration can be dynamically adjusted. This dynamic adjustment may be in response to workload of the logical partition.

Method, system and program products for managing logical processors of a computing environment

Heuristics are employed to dynamically determine whether a given request is to be driven synchronously or asynchronously. The average synchronous service time associated with previously processed requests is monitored and used, in real-time, along with other information, to determine whether the given request is to be driven synchronously or asynchronously.

Dynamically determining whether to process requests synchronously or asynchronously

A technique is disclosed for managing a workload distributed across multiple data processing systems to enhance shared resource access to meet a common performance standard. The technique includes on at least one system, measuring performance of the work units on the system to create local performance data, and on at least some of the systems sending the local performance data to at least one other system of the multiple data processing systems. The method further includes on at least one of the systems, receiving the performance data from the sending systems to create remote performance data, and adjusting at least one control parameter for accessing shared resources in response to the local and remote performance data to modify the performance of the work units distributed across the data processing systems to achieve the common performance standard. A dynamic resource clustering process is also employed to enhance the shared resource management.

Workload management method to enhance shared resource access in a multisystem environment

An impact of configuration changes on controllers is projected. This projection quantifies the impact for each controller affected by the change, such that it is known by a quantifiable value how much the change impacts the controller. In order to project the impact, a projected I/O velocity of the controller is determined.

Method, system and program products for projecting the impact of configuration changes on controllers

A method and apparatus for dynamically controlling the dispatching of a coupling facility operating in a logical partition sharing a processor resource with one or more other logical partitions issuing requests to the coupling facility. A plurality of coupling facility dispatching modes differing in their relative dispatch duration are defined. One dispatching mode is initially selected, and the number of requests received from the other logical partitions within a predetermined interval while in a selected dispatching mode is determined. Transitions between the defined dispatching modes are made in accordance with the number of requests received within the sampling interval in the selected dispatching mode. The method and apparatus are especially suitable for controlling the dispatching of a backup coupling facility, whose polling loop would otherwise consume processor resources usable by other logical

Method and apparatus for dynamically controlling the execution of a request handler on a processor resource

Disclosed is a method and computer program device for dynamically managing the assignment of alias addresses to base addresses referencing an input/output (I/O) device, such as a direct access storage device (DASD). Two distinct methods are disclosed. In one method, alias addresses are assigned based on the performance of the I/O devices. In this method, alias addresses are assigned to highly utilized devices, as indicated by device performance data, in order to maximize the efficient utilization of I/O device resources. In a second method, workload management principles are utilized to assign alias addresses. In this method, a correlation is made between each I/O device and the service classes utilizing each device. As in the first method, performance data is generated for each I/O device. Alias addresses are assigned to I/O devices experiencing queue delays as indicated by their performance data, if the device is associated with a service class that has failed to meet one or more processing goals. These methods may operate on a single host, or in a multi-host environment. The methods may be operated individually, or concurrently. Methods are disclosed to manage contention between concurrently operating assignment methods, and between multiple hosts concurrently operating one or more assignment methods.

Dynamic management of addresses to an input/output (I/O) device

A data processing system dynamically balances allocation of storage areas in a shared coupling facility that is devoted to storage of directory entries and data blocks. Each directory entry includes information regarding the validity of a data block that is locally stored by one or more processor modules in the data processing system. The system includes a coupling facility having a cache memory wherein a first portion is allocated to storage of data blocks and a second portion is allocated to storage of directory entries. Each directory entry, associated with a data block, indicates the validity or invalidity of data contained in a copy of the data block maintained by a connected computer module in its local memory. Each computer module, upon requiring a first data block and determining that (i) the first data block is present in its local memory (i.e., a buffer 'hit'), but (ii) is not marked valid and (iii) is not present in the coupling facility (i.e., a cache 'miss'), accesses the first data block from a disk store, even though the first data block in its local memory may be valid. A memory allocation procedure controls the sizes of the first portion and second portion of the cache memory. The procedure (i) maintains a record, per unit of time, of a number of cache 'miss' occurrences, (i.e., a cache 'miss' rate) and an estimate of the number of false invalidation occurrences (i.e., a false invalidation rate); derives a first order derivative of the sum of cache miss-rate and the estimated false invalidation rate and (iii) employs the derivative to adjust the sizes of the first portion and second portion of the cache memory so as to minimize the sum of the expected miss and false invalidation rate values.

Method and apparatus for determining a desirable directory/data block

A workload manager creates goal control data, defining two or more classes of system work units, in response to specification of goals of two or more goal types for the classes, and specification of importance values for each of the goal types. A system resource manager causes the goals to be met by periodically sampling work unit status; calculating a performance index for each class; selecting a receiver class to receive improved service based on the relative performance indexes and goal importance; a system bottleneck impacting achievement of goal by the receiver class is identified; and one or more system control data elements are identified and adjusted to cause the goal to be met for the receiver class.

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Millbrook, NY, United States of America

Gary M King