Intel Corporation

Universiteit Gent

Stijn Eyerman

Wim Heirman

Ibrahim Hur

Kristof Du Bois

Joshua B Fryman

Ugonna C Echeruo

Yves Vandriessche

Lieven Eeckhout

Jason M Howard

Fabrizio Petrini

Erik Hallnor

Ivan Ganev

Trevor E Carlson

Methods and apparatus relating to one or more delayed cache writeback instructions for improved data sharing in manycore processors are described. In an embodiment, a delayed cache writeback instruction causes a cache block in a modified state in a Level 1 (L1) cache of a first core of a plurality of cores of a multi-core processor to a Modified write back (M.wb) state. The M.wb state causes the cache block to be written back to LLC upon eviction of the cache block from the L1 cache. Other embodiments are also disclosed and claimed.

Delayed cache writeback instructions for improved data sharing in manycore processors

In an embodiment, a processor includes a fetch circuit to fetch instructions, the instructions including a code prefetch instruction; a decode circuit to decode the code prefetch instruction and provide the decoded code prefetch instruction to a memory circuit, the memory circuit to execute the decoded code prefetch instruction to prefetch a first set of code blocks into a first cache and to prefetch a second set of code blocks into a second cache. Other embodiments are described and claimed.

Instruction and logic for code prefetching

Methods, apparatus, systems and articles of manufacture to build a storage architecture for graph data are disclosed herein. Disclosed example apparatus include a neighbor identifier to identify respective sets of neighboring vertices of a graph. The neighboring vertices included in the respective sets are adjacent to respective ones of a plurality of vertices of the graph and respective sets of neighboring vertices are represented as respective lists of neighboring vertex identifiers. The apparatus also includes an element creator to create, in a cache memory, an array of elements that are unpopulated. The array elements have lengths equal to a length of a cache line. In addition, the apparatus includes an element populater to populate the elements with neighboring vertex identifiers. Each of the elements store neighboring vertex identifiers of respective ones of the list of neighboring vertex identifiers.

Storage architectures for graph analysis applications

Apparatus, method, and system for enhancing data prefetching based on non-uniform memory access (NUMA) characteristics are described herein. An apparatus embodiment includes a system memory, a cache, and a prefetcher. The system memory includes multiple memory regions, at least some of which are associated with different NUMA characteristic (access latency, bandwidth, etc.) than others. Each region is associated with its own set of prefetch parameters that are set in accordance to their respective NUMA characteristics. The prefetcher monitors data accesses to the cache and generates one or more prefetch requests to fetch data from the system memory to the cache based on the monitored data accesses and the set of prefetch parameters associated with the memory region from which data is to be fetched. The set of prefetcher parameters may include prefetch distance, training-to-stable threshold, and throttle threshold.

Apparatus, method, and system for enhanced data prefetching based on non-uniform memory access (NUMA) characteristics

A method for simulating a set of instructions to be executed on a processor including performing a performance simulation of the processor over a number of simulation cycles. Modeling, in a frontend component, branch prediction and instruction cache is performed providing instructions to the instruction window, and modeling of an instruction window for the cycle is performed. From the simulation, a performance parameter of the processor is obtained without modeling a reorder buffer, issue queue(s), register renaming, load-store queue(s) and other buffers of the processor.

Instruction window centric processor simulation

In one embodiment, an apparatus includes a memory access circuit to receive memory access instructions and provide at least some of the memory access instructions to a memory subsystem for execution. The memory access circuit may have a conversion circuit to convert the first memory access instruction to a first subline memory access instruction, e.g., based at least in part on an access history for a first memory access instruction. Other embodiments are described and claimed.

System, apparatus and method for dynamic automatic sub-cacheline granularity memory access control

Embodiment of this disclosure provides a mechanism to store cache lines in dedicated cache of an idle core. In one embodiment, a multi-core processor comprising a first core, a second core, a first cache, a second cache, a third cache, and a cache controller unit is provided. The cache controller is operatively coupled to at least the first cache, the second cache, and the third cache. The cache controller is to evict a first line from the first cache, wherein the first core is in an active state. Responsive to the evicting of the first line, the first line is stored in the third cache. Responsive to storing the first line, a second line is evicted from the third cache. Responsive to evicting the second line, the second line is stored in the second cache when the second core is in an idle state.

Storing cache lines in dedicated cache of an idle core

Disclosed embodiments relate to an indirect memory fetch (IMF) unit. In one example, an apparatus includes circuitry to fetch and decode an instruction specifying a sparse operand array including N operands, and an index array including N contiguously-addressed indices. The apparatus further includes a processing engine associated with an IMF unit to respond to the decoded instruction by initializing the IMF unit to fetch the N operands in order, probing the IMF unit to determine that a fetched operand is ready to retrieve, retrieving the fetched operand from the IMF unit, and repeating the probing and retrieving until all N operands have been retrieved. The IMF unit, independent of the processing engine, is to fetch the N contiguously-addressed indices from the index array, use the N fetched indices to calculate memory addresses for the N operands, and issue a plurality of read requests to fetch the N operands in order.

Indirect memory fetcher

Embodiments of apparatuses, methods, and systems for independent tuning of multiple hardware prefetchers are described. In an embodiment, an apparatus includes a processor core, a cache memory, a hardware prefetcher, and a prefetch tuner. The hardware prefetcher is to prefetch data for the processor core from a system memory to the cache memory. The prefetch tuner is to adjust a prefetch rate of the hardware prefetcher based on a fraction of late prefetches. The prefetch tuner includes a late prefetch counter to count a number of late prefetches for the hardware prefetcher, a prefetch counter to count a number of prefetches for the hardware prefetcher, and a late prefetch calculator to calculate the fraction of late prefetches based on the number of late prefetches and the number of prefetches.

Independent tuning of multiple hardware prefetchers

A counter architecture and a corresponding method are provided for estimating a profitability value of DVFS for a unit of work running on a computing device. The counter architecture and the corresponding method are arranged for dividing total execution time for executing a unit of work on the computing device into a pipelined fraction subject to clock frequency and a non-pipelined fraction due to off-chip memory accesses, and for estimating the DVFS profitability value from the pipelined and the non-pipelined fraction.

Growing community of inventors

Evergem, Belgium

Stijn Eyerman