Abstract: Embodiments relate to thread-based cache content savings for task switching in a computer processor. An aspect includes determining a cache entry in a cache of the computer processor that is owned by the first thread, wherein the determination is made based on a hardware thread identifier (ID) of the first thread matching a hardware thread ID in the cache entry. Another aspect includes determining whether the determined cache entry is eligible for prefetching. Yet another aspect includes, based on determining that the determined cache entry is eligible for prefetching, setting a marker in the cache entry to active.

Abstract: Systems and methods to manage memory on a spin transfer torque magnetoresistive random-access memory (STT-MRAM) are provided. A particular method may include determining a performance characteristic using relationship information that relates a bit error rate to at least one of a programming pulse width, a temperature, a history-based predictive performance parameter, a coding scheme, and a voltage level also associated with a memory. The performance characteristic is stored and used to manage a write operation associated with the memory.

Abstract: Embodiments relate to pre-computation slice (p-slice) merging for prefetching in a computer processor. An aspect includes determining a plurality of p-slices corresponding to a delinquent instruction. Another aspect includes selecting a first p-slice and a second p-slice of the plurality of p-slices. Another aspect includes traversing the first p-slice and the second p-slice to determine that divergent instructions exist between the first p-slice and the second p-slice. Another aspect includes, based on determining that divergent instructions exist between the first p-slice and the second p-slice, determining whether the first p-slice and the second p-slice converge after the divergent instructions. Another aspect includes, based on determining that the first p-slice and the second p-slice converge after the divergent instructions, merging the first p-slice and the second p-slice into a single merged p-slice.

Abstract: Cache miss rates for threads operating in a simultaneous multi-threading computer processing environment can be estimated. The single thread rates can be estimated by monitoring a shared directory for cache misses for a first thread. Memory access requests can be routed to metering cache directories associated with the particular thread. Single thread misses to the shared directory and single thread misses to the associated metering cache directory are monitored and a performance indication is determined by comparing the cache misses with the thread misses. The directory in the associated metering cache is rotated, and a second sharing performance indication is determined.

Abstract: Cache miss rates for threads operating in a simultaneous multi-threading computer processing environment can be estimated. The single thread rates can be estimated by monitoring a shared directory for cache misses for a first thread. Memory access requests can be routed to metering cache directories associated with the particular thread. Single thread misses to the shared directory and single thread misses to the associated metering cache directory are monitored and a performance indication is determined by comparing the cache misses with the thread misses. The directory in the associated metering cache is rotated, and a second sharing performance indication is determined.

Abstract: A mechanism is provided for memory coherence in a multiple processor system. Responsive to a memory operation from a processing core of the multiple processor system resulting in a cache miss, the mechanism checks a private region table associated with the processing core. The memory operation attempts to access a memory region. Responsive to determining the memory region corresponds to an entry in the private region table, the mechanism performs a remote memory controller snoop of a remote memory controller without snooping the multiple processor system.

Abstract: Systems and methods to manage memory on a spin transfer torque magnetoresistive random-access memory (STT-MRAM) are provided. A particular method may include determining a performance characteristic using relationship information that relates a bit error rate to at least one of a programming pulse width, a temperature, a history-based predictive performance parameter, a coding scheme, and a voltage level also associated with a memory. The performance characteristic is stored and used to manage a write operation associated with the memory.

Abstract: A mechanism is provided for memory coherence in a multiple processor system. Responsive to a memory operation from a processing core of the multiple processor system resulting in a cache miss, the mechanism checks a private region table associated with the processing core. The memory operation attempts to access a memory region. Responsive to determining the memory region corresponds to an entry in the private region table, the mechanism performs a remote memory controller snoop of a remote memory controller without snooping the multiple processor system.

Abstract: Systems and methods to manage memory on a spin transfer torque magnetoresistive random-access memory (STT-MRAM) are provided. A particular method of managing memory includes determining a temperature associated with the memory and determining a level of write queue utilization associated with the memory. A write operation may be performed based on the level of write queue utilization and the temperature.

Abstract: Systems and methods to manage memory on a spin transfer torque magnetoresistive random-access memory (STT-MRAM) are provided. A particular method of managing memory includes determining a temperature associated with the memory and determining a level of write queue utilization associated with the memory. A write operation may be performed based on the level of write queue utilization and the temperature.

Abstract: Embodiments relate to a non-data inclusive coherent (NIC) directory for a symmetric multiprocessor (SMP) of a computer. An aspect includes determining a first eviction entry of a highest-level cache in a multilevel caching structure of the first processor node of the SMP. Another aspect includes determining that the NIC directory is not full. Another aspect includes determining that the first eviction entry of the highest-level cache is owned by a lower-level cache in the multilevel caching structure. Another aspect includes, based on the NIC directory not being full and based on the first eviction entry of the highest-level cache being owned by the lower-level cache, installing an address of the first eviction entry of the highest-level cache in a first new entry in the NIC directory. Another aspect includes invalidating the first eviction entry in the highest-level cache.

Abstract: A computer-implemented method for instruction execution in a pipeline, includes fetching, in the pipeline, a plurality of instructions, wherein the plurality of instructions includes a plurality of branch instructions, for each of the plurality of branch instructions, assigning a branch uncertainty to each of the plurality of branch instructions, for each of the plurality of instructions, assigning an instruction uncertainty that is a summation of branch uncertainties of older unresolved branches, and balancing the instructions, based on a current summation of instruction uncertainty, in the pipeline.

Abstract: Embodiments relate to a non-data inclusive coherent (NIC) directory for a symmetric multiprocessor (SMP) of a computer. An aspect includes determining a first eviction entry of a highest-level cache in a multilevel caching structure of the first processor node of the SMP. Another aspect includes determining that the NIC directory is not full. Another aspect includes determining that the first eviction entry of the highest-level cache is owned by a lower-level cache in the multilevel caching structure. Another aspect includes, based on the NIC directory not being full and based on the first eviction entry of the highest-level cache being owned by the lower-level cache, installing an address of the first eviction entry of the highest-level cache in a first new entry in the NIC directory. Another aspect includes invalidating the first eviction entry in the highest-level cache.

Abstract: Embodiments relate to thread-based cache content savings for task switching in a computer processor. An aspect includes determining a cache entry in a cache of the computer processor that is owned by the first thread, wherein the determination is made based on a hardware thread identifier (ID) of the first thread matching a hardware thread ID in the cache entry. Another aspect includes determining whether the determined cache entry is eligible for prefetching. Yet another aspect includes, based on determining that the determined cache entry is eligible for prefetching, setting a marker in the cache entry to active.

Abstract: Embodiments relate to thread-based cache content savings for task switching in a computer processor. An aspect includes determining a cache entry in a cache of the computer processor that is owned by the first thread, wherein the determination is made based on a hardware thread identifier (ID) of the first thread matching a hardware thread ID in the cache entry. Another aspect includes determining whether the determined cache entry is eligible for prefetching. Yet another aspect includes, based on determining that the determined cache entry is eligible for prefetching, setting a marker in the cache entry to active.

Abstract: A scheme referred to as a “Region-based cache restoration prefetcher” (RECAP) is employed for cache preloading on a partition or a context switch. The RECAP exploits spatial locality to provide a bandwidth-efficient prefetcher to reduce the “cold” cache effect caused by multiprogrammed virtualization. The RECAP groups cache blocks into coarse-grain regions of memory, and predicts which regions contain useful blocks that should be prefetched the next time the current virtual machine executes. Based on these predictions, and using a simple compression technique that also exploits spatial locality, the RECAP provides a robust prefetcher that improves performance without excessive bandwidth overhead or slowdown.

Abstract: A computer system for instruction execution includes a processor having a pipeline. The system is configured to perform a method including fetching, in the pipeline, a plurality of instructions, wherein the plurality of instructions includes a plurality of branch instructions, for each of the plurality of branch instructions, assigning a branch uncertainty to each of the plurality of branch instructions, for each of the plurality of instructions, assigning an instruction uncertainty that is a summation of branch uncertainties of older unresolved branches and balancing the instructions, based on a current summation of instruction uncertainty, in the pipeline.

Abstract: A scheme referred to as a “Region-based cache restoration prefetcher” (RECAP) is employed for cache preloading on a partition or a context switch. The RECAP exploits spatial locality to provide a bandwidth-efficient prefetcher to reduce the “cold” cache effect caused by multiprogrammed virtualization. The RECAP groups cache blocks into coarse-grain regions of memory, and predicts which regions contain useful blocks that should be prefetched the next time the current virtual machine executes. Based on these predictions, and using a simple compression technique that also exploits spatial locality, the RECAP provides a robust prefetcher that improves performance without excessive bandwidth overhead or slowdown.

Abstract: Systems and methods to manage memory on a spin transfer torque magnetoresistive random-access memory (STT-MRAM) are provided. A particular method of managing memory includes determining a temperature associated with the memory and determining a level of write queue utilization associated with the memory. A write operation may be performed based on the level of write queue utilization and the temperature.

Abstract: Systems and methods to manage memory on a spin transfer torque magnetoresistive random-access memory (STT-MRAM) are provided. A particular method of managing memory includes determining a temperature associated with the memory and determining a level of write queue utilization associated with the memory. A write operation may be performed based on the level of write queue utilization and the temperature.