Intel Corporation

Varun Mohandru

Fernando Latorre

Steffen Kosinski

Li-Gao Zei

Niranjan L Cooray

Pedro Lopez

Jaroslaw Topp

Rami May

Lutz Naethke

Naveen Neelakantam

Stanislav Shwartsman

Allan Douglas Knies

Demos Pavlou

Mirem Hyuseinova

Ralf Goettsche

Thomas Gaertner

Doron Gershon

Ethan Kalifon

Tom Aviram-Rosenfeld

Jaroslav Topp

A virtually tagged cache may be configured to index virtual address entries in the cache into lockable sets based on a page offset value. When a memory operation misses on the virtually tagged cache, only the one set of virtual address entries with the same page offset may be locked. Thereafter, this general lock may be released and only an address stored in the physical tag array matching the physical address and a virtual address in the virtual tag array corresponding to the matching address stored in the physical tag array may be locked to reduce the amount and duration of locked addresses. The machine may be stalled only if a particular memory address request hits and/or tries to access one or more entries in a locked set. Devices, systems, methods, and computer readable media are provided.

Two-level cache locking mechanism

A bit or other vector may be used to identify whether an address range entered into an intermediate buffer corresponds to most recently updated data associated with the address range. A bit or other vector may also be used to identify whether an address range entered into an intermediate buffer overlaps with an address range of data that is to be loaded. A processing device may then determine whether to obtain data that is to be loaded entirely from a cache, entirely from an intermediate buffer which temporarily buffers data destined for a cache until the cache is ready to accept the data, or from both the cache and the intermediate buffer depending on the particular vector settings. Systems, devices, methods, and computer readable media are provided.

Store forwarding for data caches

A system and method to implement a tag structure for a cache memory that includes a multi-way, set-associative translation lookaside buffer. The tag structure may store vectors in an L1 tag array to enable an L1 tag lookup that has fewer bits per entry and consumes less power. The vectors may identify entries in a translation lookaside buffer tag array. When a virtual memory address associated with a memory access instruction hits in the translation lookaside buffer, the translation lookaside buffer may generate a vector identifying the set and the way of the translation lookaside buffer entry that matched. This vector may then be compared to a group of vectors stored in a set of the L1 tag arrays to determine whether the virtual memory address hits in the L1 cache.

Power efficient level one data cache access with pre-validated tags

A system and method for adaptive data prefetching in a processor enables adaptive modification of parameters associated with a prefetch operation. A stride pattern in successive addresses of a memory operation may be detected, including determining a stride length (L). Prefetching of memory operations may be based on a prefetch address determined from a base memory address, the stride length L, and a prefetch distance (D). A number of prefetch misses may be counted at a miss prefetch count (C). Based on the value of the miss prefetch count C, the prefetch distance D may be modified. As a result of adaptive modification of the prefetch distance D, an improved rate of cache hits may be realized.

Adaptive data prefetching

Responsive to execution of a computer instruction in a current translation window, state indicators associated with a cache line accessed for the execution may be modified. The state indicators may include: a first indicator to indicate whether the computer instruction is a load instruction moved from a subsequent translation window into the current translation window, a second indicator to indicate whether the cache line is modified in a cache responsive to the execution of the computer instruction, a third indicator to indicate whether the cache line is speculatively modified in the cache responsive to the execution of the computer instruction, a fourth indicator to indicate whether the cache line is speculatively loaded by the computer instruction, a fifth indicator to indicate whether a core executing the computer instruction exclusively owns the cache line, and a sixth indicator to indicate whether the cache line is invalid.

Cache coherency and processor consistency

A processor includes a processor core including an execution unit to execute instructions, and a cache memory. The cache memory includes a controller to update each of a plurality of stale indicators in response to a lazy flush instruction. Each stale indicator is associated with respective data, and each updated stale indicator is to indicate that the respective data is stale. The cache memory also includes a plurality of cache lines. Each cache line is to store corresponding data and a foreground tag that includes a respective virtual address associated with the corresponding data, and that includes the associated stale indicator. Other embodiments are described as claimed.

Method and apparatus to implement lazy flush in a virtually tagged cache memory

Growing community of inventors

Braunschweig, Germany

Varun Mohandru