A method for heap space management includes, in response to a determination that consumption of a first heap space of an application exceeds a first threshold, determining whether a second heap space of the application after garbage collection is sufficient to accommodate data stored in the first heap space. The method further includes, in response to a determination that the second heap space after the garbage collection is sufficient to accommodate the data, performing the garbage collection on the second heap space. The method further includes storing the data into the second heap space.

Aspects are provided for sharing instruction cache footprint between multiple threads. A set/way pointer to an instruction cache line is derived from a system memory address associated with an instruction fetch from a memory page. It is determined that the instruction cache line is shareable between the first thread and the second thread. An alias table entry is created indicating that other instruction cache lines associated with the memory page are also shareable between threads. Another instruction fetch is received from another thread requesting an instruction from another system memory address associated with the memory page. A further set/way pointer to another instruction cache line is derived from the other system memory address. It is determined that the other instruction cache line is sharable based on the alias table entry.

Aspects are provided for sharing instruction cache footprint between multiple threads. A set/way pointer to an instruction cache line is derived from a system memory address associated with an instruction fetch from a memory page. It is determined that the instruction cache line is shareable between the first thread and the second thread. An alias table entry is created indicating that other instruction cache lines associated with the memory page are also shareable between threads. Another instruction fetch is received from another thread requesting an instruction from another system memory address associated with the memory page. A further set/way pointer to another instruction cache line is derived from the other system memory address. It is determined that the other instruction cache line is sharable based on the alias table entry.

Aspects are provided for sharing instruction cache footprint between multiple threads using instruction cache set/way pointers and a tracking table. The tracking table is built up over time for shared pages, even when the instruction cache has no access to real addresses or translation information. A set/way pointer to an instruction cache line is derived from the system memory address associated with a first thread's instruction fetch. The set/way pointer is stored as a surrogate for the system memory address in both an instruction cache directory (IDIR) and a tracking table. Another set/way pointer to an instruction cache line is derived from the system memory address associated with a second thread's instruction fetch. A match is detected between the set/way pointer and the other set/way pointer. The instruction cache directory is updated to indicate that the instruction cache line is shared between multiple threads.

Aspects are provided for sharing instruction cache footprint between multiple threads using instruction cache set/way pointers and a tracking table. The tracking table is built up over time for shared pages, even when the instruction cache has no access to real addresses or translation information. A set/way pointer to an instruction cache line is derived from the system memory address associated with a first thread's instruction fetch. The set/way pointer is stored as a surrogate for the system memory address in both an instruction cache directory (IDIR) and a tracking table. Another set/way pointer to an instruction cache line is derived from the system memory address associated with a second thread's instruction fetch. A match is detected between the set/way pointer and the other set/way pointer. The instruction cache directory is updated to indicate that the instruction cache line is shared between multiple threads.

Resource lock ownership identification is provided across processes and systems of a clustered computing environment by a method which includes saving by a process, based on a user acquiring a resource lock, a lock information record to a shared data structure of the clustered computing environment. The lock information record includes user identification data identifying the user-owner of the resource lock acquired on a system executing the process. The method also includes referencing, by another process, the lock information record of the shared data structure to ascertain the user identification data identifying the user-owner of the resource lock, and thereby facilitate processing within the clustered computing environment.

A load-store unit (LSU) of a processor core determines whether or not a second store operation specifies an adjacent update to that specified by a first store operation. The LSU additionally determines whether the total store data length of the first and second store operations exceeds a maximum size. Based on determining the second store operation specifies an adjacent update and the total store data length does not exceed the maximum size, the LSU merges the first and second store operations and writes merged store data into a same write block of a cache. Based on determining that the total store data length exceeds the maximum size, the LSU splits the second store operation into first and second portions, merges the first portion with the first store operation, and writes store data of the partially merged store operation into the write block.

A load-store unit (LSU) of a processor core determines whether or not a second store operation specifies an adjacent update to that specified by a first store operation. The LSU additionally determines whether the total store data length of the first and second store operations exceeds a maximum size. Based on determining the second store operation specifies an adjacent update and the total store data length does not exceed the maximum size, the LSU merges the first and second store operations and writes merged store data into a same write block of a cache. Based on determining that the total store data length exceeds the maximum size, the LSU splits the second store operation into first and second portions, merges the first portion with the first store operation, and writes store data of the partially merged store operation into the write block.

An apparatus comprises an interconnect providing communication paths between agents coupled to the interconnect. A coordination agent is provided which performs an operation requiring sending a request to each of a plurality of target agents, and receiving a response from each of the target agents, the operation being unable to complete until the response has been received from each of the target agents. Storage circuitry is provided which is accessible to the coordination agent and configured to store, for each agent that the coordination agent may communicate with via the interconnect, a latency indication for communication between that agent and the coordination agent. The coordination agent is configured, prior to performing the operation, to determine a sending order in which to send the request to each of the target agents, the sending order being determined in dependence on the latency indication for each of the target agents.

An apparatus comprises an interconnect providing communication paths between agents coupled to the interconnect. A coordination agent is provided which performs an operation requiring sending a request to each of a plurality of target agents, and receiving a response from each of the target agents, the operation being unable to complete until the response has been received from each of the target agents. Storage circuitry is provided which is accessible to the coordination agent and configured to store, for each agent that the coordination agent may communicate with via the interconnect, a latency indication for communication between that agent and the coordination agent. The coordination agent is configured, prior to performing the operation, to determine a sending order in which to send the request to each of the target agents, the sending order being determined in dependence on the latency indication for each of the target agents.