G06F12/0833

Data cache with hybrid writeback and writethrough

Described is a data cache implementing hybrid writebacks and writethroughs. A processing system includes a memory, a memory controller, and a processor. The processor includes a data cache including cache lines, a write buffer, and a store queue. The store queue writes data to a hit cache line and an allocated entry in the write buffer when the hit cache line is initially in at least a shared coherence state, resulting in the hit cache line being in a shared coherence state with data and the allocated entry being in a modified coherence state with data. The write buffer requests and the memory controller upgrades the hit cache line to a modified coherence state with data based on tracked coherence states. The write buffer retires the data upon upgrade. The data cache writebacks the data to memory for a defined event.

PREFETCHER WITH LOW-LEVEL SOFTWARE CONFIGURABILITY

An embodiment of an integrated circuit may comprise a prefetcher, a model specific register that is accessible at runtime to store information associated with the prefetcher, and circuitry communicatively coupled to the model specific register and prefetcher to adjust a runtime operation of the prefetcher based on the information associated with the prefetcher stored in the model specific register. Other embodiments are disclosed and claimed.

PROBE FILTER DIRECTORY MANAGEMENT

A data processing system includes a plurality of coherent masters, a plurality of coherent slaves, and a coherent data fabric. The coherent data fabric has upstream ports coupled to the plurality of coherent masters and downstream ports coupled to the plurality of coherent slaves for selectively routing accesses therebetween. The coherent data fabric includes a probe filter and a directory cleaner. The probe filter is associated with at least one of the downstream ports and has a plurality of entries that store information about each entry. The directory cleaner periodically scans the probe filter and selectively removes a first entry from the probe filter after the first entry is scanned.

Managing aliasing in a virtually indexed physically tagged cache

A circuit includes a Virtually Indexed Physically Tagged (VIPT) cache and a cache coherency circuit. The VIPT cache includes a plurality of sets and performs a memory operation by selecting, using a Virtual Set Address (VSA), a first tag of a first set. The cache coherency circuit is to detect cache aliasing during memory operations of the VIPT cache when a second tag maps a physical address to a second set of the VIPT cache, the second set being different than the first set. A method of managing a VIPT cache includes performing, by the VIPT cache, a memory operation and determining, using a cache coherency protocol, that cache aliasing has occurred during the memory operation.

Storage apparatus and method that generates preliminary management information including the same content as main management information for identifying physical address of data
11681612 · 2023-06-20 · ·

A storage apparatus includes: a memory that stores data and main management information, the main management information identifying a physical address of the data; and processing circuitry configured to generate preliminary management information that includes information of the same content as the main management information, and select, as use management information, any one of the main management information and the preliminary management information upon start of the storage apparatus. Access to the data stored in the memory is performed using the selected use management information.

PRESERVATION OF MODIFIED CACHE DATA IN LOCAL NON-VOLATILE STORAGE FOLLOWING A FAILOVER

A dual-server based storage system maintains a first cache and a first non-volatile storage (NVS) in a first server, and a second cache and a second NVS in a second server, where data in the first cache is also written in the second NVS and data in the second cache is also written in the first NVS. In response to a failure of the first server, a determination is made as to whether space exists in the second NVS to accommodate the data stored in the second cache. In response to determining that space exists in the second NVS to accommodate the data stored in the second cache, the data is transferred from the second cache to the second NVS.

Draining operation to cause store data to be written to persistent memory

An apparatus comprises a write buffer to buffer store requests issued by the processing circuitry, prior to the store data being written to at least one cache. Draining circuitry detects a draining trigger event having potential to cause loss of state stored in the at least one cache. In response to the draining trigger event, the draining circuitry performs a draining operation to identify whether the write buffer buffers any committed store requests requiring persistence, and when the write buffer buffers at least one committed store request requiring persistence, to cause the store data associated with the at least one committed store request to be written to persistent memory. This helps to eliminate barrier instructions from software, simplifying persistent programming and improving performance.

Method, apparatus and system for dynamically controlling an addressing mode for a cache memory

In an embodiment, a first portion of a cache memory is associated with a first core. This first cache memory portion is of a distributed cache memory, and may be dynamically controlled to be one of a private cache memory for the first core and a shared cache memory shared by a plurality of cores (including the first core) according to an addressing mode, which itself is dynamically controllable. Other embodiments are described and claimed.

ADAPTIVE CREDIT-BASED REPLENISHMENT THRESHOLD USED FOR TRANSACTION ARBITRATION IN A SYSTEM THAT SUPPORTS MULTIPLE LEVELS OF CREDIT EXPENDITURE
20220374358 · 2022-11-24 ·

A device includes an arbiter circuit configured to receive a first request for a resource. The first request is associated with a first credit cost. The arbiter circuit is further configured to receive a second request for the resource. The second request is associated with a second credit cost. The arbiter circuit is further configured to select the first request for the resource as an arbitration winner. The arbiter circuit is further configured to decrement a number of available credits associated with the resource by the first credit cost. The arbiter circuit is further configured to, in response to the number of available credits associated with the resource falling to a lower credit threshold, wait until the number of available credits associated with the resource reaches an upper credit threshold to select an additional arbitration winner for the resource.

Synchronizing updates of page table status indicators and performing bulk operations

A synchronization capability to synchronize updates to page tables by forcing updates in cached entries to be made visible in memory (i.e., in in-memory page table entries). A synchronization instruction is used that ensures after the instruction has completed that updates to the cached entries that occurred prior to the synchronization instruction are made visible in memory. Synchronization may be used to facilitate memory management operations, such as bulk operations used to change a large section of memory to read-only, operations to manage a free list of memory pages, and/or operations associated with terminating processes.