Abstract: A translation lookaside buffer coherency unit with Emulated Purge (TCUEP) fetches first instructions for execution in a multi-processor system. The TCUEP associates a first instruction timestamp with each of the first instructions. The TCUEP receives a multi-processor coherency operation and increments the first timestamp value in a master-tag register to form a second timestamp value after receiving the multi-processor coherency operation. The TCUEP fetches, by an instruction fetch unit in the first microprocessor, second instructions for execution in the multiprocessor system. The TCUEP associates a second instruction timestamp with each of the second instructions. The TCUEP enables an emulated purge mechanism to suppress hits in the translation lookaside buffers for the second instructions. The TCUEP after determining the first instructions are complete, purges entries in the translation lookaside buffers and disables the emulated purge mechanism.

Abstract: A computing system method, program and hardware for correlation of millicode predictions with specific millicode routines receives architected millicode and stores the millicode in internal memory. The computer systems processors' pipeline is employed to predict and select a branch target buffer's (BTB) target address. A computer millicode control enabling an operating system (O/S) multi-task control between multiple user programs able to use millicode routines and ensuring that the programs do not interfere with each other, by use of a branch target buffer (BTB) prediction of a branch target to ensure that a millicode routine does not fetch outside of said millicode routine while performing operations as required by said millicode routing, said branch target buffer prediction employing a correlation mechanism for predicting millicoded branch millicode entry and millicode end instructions and for correlating millicode end predictions with specific millicode routines.

Abstract: A translation lookaside buffer coherency unit with Emulated Purge (TCUEP) fetches first instructions for execution in a multi-processor system. The TCUEP associates a first instruction timestamp with each of the first instructions. The TCUEP receives a multi-processor coherency operation and increments the first timestamp value in a master-tag register to form a second timestamp value after receiving the multi-processor coherency operation. The TCUEP fetches, by an instruction fetch unit in the first microprocessor, second instructions for execution in the multiprocessor system. The TCUEP associates a second instruction timestamp with each of the second instructions. The TCUEP enables an emulated purge mechanism to suppress hits in the translation lookaside buffers for the second instructions. The TCUEP after determining the first instructions are complete, purges entries in the translation lookaside buffers and disables the emulated purge mechanism.

Abstract: What is provided is an enhanced dynamic address translation facility. In one embodiment, a virtual address to be translated is first obtained and an initial origin address of a translation table of the hierarchy of translation tables is obtained. Based on the obtained initial origin, a segment table entry is obtained. The segment table entry is configured to contain a format control and access validity fields. If the format control and access validity fields are enabled, the segment table entry further contains an access control field, a fetch protection field, and a segment-frame absolute address. Store operations are permitted only if the access control field matches a program access key provided by any one of a Program Status Word or an operand of a program instruction being emulated. Fetch operations are permitted if the program access key associated with the virtual address is equal to the segment access control field or the fetch protection field is not enabled.

Abstract: What is provided is an enhanced dynamic address translation facility. In one embodiment, a virtual address to be translated is first obtained and an initial origin address of a translation table of the hierarchy of translation tables is obtained. Based on the obtained initial origin, a segment table entry is obtained. The segment table entry is configured to contain a format control and access validity fields. If the format control and access validity fields are enabled, the segment table entry further contains an access control field, a fetch protection field, and a segment-frame absolute address. Store operations are permitted only if the access control field matches a program access key provided by any one of a Program Status Word or an operand of a program instruction being emulated. Fetch operations are permitted if the program access key associated with the virtual address is equal to the segment access control field or the fetch protection field is not enabled.

Abstract: Optimizations are provided for frame management operations, including a clear operation and/or a set storage key operation, requested by pageable guests. The operations are performed, absent host intervention, on frames not resident in host memory. The operations may be specified in an instruction issued by the pageable guests.

Abstract: A translation table entry contains a change recording override field for controlling whether a change bit is to be set on a store or not. Each 4K byte block of main storage has an associated storage key comprising a change bit. The change recording override field controls whether change bit of the storage key associated with the desired 4K byte block of main storage is set to 1 for a store operation.

Abstract: Creating a computer program product or a computer system to execute a frame management instruction which identifies a first and second general register. The first general register contains a frame management field having a key field with access-protection bits and a block-size indication. If the block-size indication indicates a large block then an operand address of a large block of data is obtained from the second general register. The large block of data has a plurality of small blocks each of which is associated with a corresponding storage key having a plurality of storage key access-protection bits. If the block size indication indicates a large block, the storage key access-protection bits of each corresponding storage key of each small block within the large block is set with the access-protection bits of the key field.

Abstract: Optimizations are provided for frame management operations, including a clear operation and/or a set storage key operation, requested by pageable guests. The operations are performed, absent host intervention, on frames not resident in host memory. The operations may be specified in an instruction issued by the pageable guests.

Abstract: What is provided is a load page table entry address function defined for a machine architecture of a computer system. In one embodiment, a machine instruction is obtained which contains an opcode indicating that a load page table entry address function is to be performed. The machine instruction contains an M field, a first field identifying a first general register, and a second field identifying a second general register. Based on the contents of the M field, an initial origin address of a hierarchy of address translation tables having at least one segment table is obtained. Based on the obtained initial origin address, dynamic address translation is performed until a page table entry is obtained. The page table entry address is saved in the identified first general register.

Abstract: Optimizations are provided for frame management operations, including a clear operation and/or a set storage key operation, requested by pageable guests. The operations are performed, absent host intervention, on frames not resident in host memory. The operations may be specified in an instruction issued by the pageable guests.

Abstract: What is disclosed is a frame management function defined for a machine architecture of a computer system. In one embodiment, a frame management instruction is obtained which identifies a first and second general register. The first general register contains a frame management field having a key field with access-protection bits and a block-size indication. If the block-size indication indicates a large block then an operand address of a large block of data is obtained from the second general register. The large block of data has a plurality of small blocks each of which is associated with a corresponding storage key having a plurality of storage key access-protection bits. If the block size indication indicates a large block, the storage key access-protection bits of each corresponding storage key of each small block within the large block is set with the access-protection bits of the key field.

Abstract: An instruction is provided to perform invalidation of an instruction specified range of segment table entries or region table entries. The instruction can be implemented by software emulation, hardware, firmware or some combination thereof.

Abstract: A measurement sampling facility takes snapshots of the central processing unit (CPU) on which it is executing at specified sampling intervals to collect data relating to tasks executing on the CPU. The collected data is stored in a buffer, and at selected times, an interrupt is provided to remove data from the buffer to enable reuse thereof. The interrupt is not taken after each sample, but in sufficient time to remove the data and minimize data loss.

Abstract: Aspects include a system, method and computer program product for providing a shared memory translation facility. The method includes receiving a request for access to a memory address from a requestor at a configuration, the receiving at a shared memory translation mechanism. It is determined whether the memory address refers to a shared memory object (SMO), the SMO accessible by a plurality of configurations managed in different zones of memory. Based on determining that the memory address refers to the SMO, it is determined whether the configuration has access to the SMO. Based on determining that the configuration has access to the SMO, the requestor is provided a system absolute address for the SMO and access to the SMO. In this manner direct interchange of data between the configuration and the plurality of configurations is allowed.

Abstract: Processing within a computing environment that supports pageable guests is facilitated. Processing is facilitated in many ways, including, but not limited to, associating guest and host state information with guest blocks of storage; maintaining the state information in control blocks in host memory; enabling the changing of states; and using the state information in management decisions. In one particular example, the guest state includes an indication of usefulness and importance of memory contents to the guest, and the host state reflects the ease of access to memory contents. The host and guest state information is used in managing memory of the host and/or guests.

Abstract: Host page management assist functions are employed to manage storage of a pageable mode virtual environment. These functions enable storage to be managed by a processor of the environment absent intervention of a host of the environment. The functions include a resolve host page function; a pin function; and unpin functions.

Abstract: A measurement sampling facility takes snapshots of the central processing unit (CPU) on which it is executing at specified sampling intervals to collect data relating to tasks executing on the CPU. The collected data is stored in a buffer, and at selected times, an interrupt is provided to remove data from the buffer to enable reuse thereof. The interrupt is not taken after each sample, but in sufficient time to remove the data and minimize data loss.

Abstract: A translation table entry contains a change recording override field for controlling whether a change bit is to be set on a store or not. Each 4K byte block of main storage has an associated storage key comprising a change bit. The change recording override field controls whether change bit of the storage key associated with the desired 4K byte block of main storage is set to 1 for a store operation.

Abstract: An enhanced dynamic address translation facility is provided. In one embodiment, a virtual address to be translated and an initial origin address of a translation table of the hierarchy of translation tables are obtained. An index portion of the virtual address is used to reference an entry in the translation table. If a format control field contained in the translation table entry is enabled, the table entry contains a frame address of a large block of data of at least 1M byte in size. The frame address is then combined with an offset portion of the virtual address to form the translated address of a small 4K byte block of data in main storage or memory.