Methods, apparatus, systems and articles of manufacture are disclosed for allocation in a victim cache system. An example apparatus includes a first cache storage, a second cache storage, a cache controller coupled to the first cache storage and the second cache storage and operable to receive a memory operation that specifies an address, determine, based on the address, that the memory operation evicts a first set of data from the first cache storage, determine that the first set of data is unmodified relative to an extended memory, and cause the first set of data to be stored in the second cache storage.

Data units are stored in private caches in nodes of a multiprocessor system, each node containing at least one processor (CPU), at least one cache private to the node and at least one cache location buffer (CLB) private to the node. In each CLB location information values are stored, each location information value indicating a location associated with a respective data unit, wherein each location information value stored in a given CLB indicates the location to be either a location within the private cache disposed in the same node as the given CLB, to be a location in one of the other nodes, or to be a location in a main memory. Coherence of values of the data units is maintained using a cache coherence protocol. The location information values stored in the CLBs are updated by the cache coherence protocol in accordance with movements of their respective data units.

In accordance with various aspects of the invention, a recall transaction is issued if a tag filter entry needs to be freed up for an incoming transaction. Directory entries chosen for a recall transaction are pushed into a fully associative structure called victim buffer. If this structure gets full, then an entry is selected from entries inside the victim buffer for the recall.

Systems, devices and methods are provided for operating a skewed-associative cache in a data processing system and, in particular, for changing address-to-row mappings in a skewed-associative cache.

A system includes a first counter configured to increment or decrement in response to a triggering event. The first counter is sized to overflow. The system also includes a second counter configured to increment or decrement in response to a triggering event. The first counter and the second counter are merged to form a third counter in response to detecting an overflow triggering event for the first counter. A merge bit indicative of whether the first counter and the second counter are merged changes value in response to merging the first counter and the second counter.

Methods, apparatus, systems and articles of manufacture are disclosed facilitate read-modify-write support in a coherent victim cache with parallel data paths. An example apparatus includes a random-access memory configured to be coupled to a central processing unit via a first interface and a second interface, the random-access memory configured to obtain a read request indicating a first address to read via a snoop interface, an address encoder coupled to the random-access memory, the address encoder to, when the random-access memory indicates a hit of the read request, generate a second address corresponding to a victim cache based on the first address, and a multiplexer coupled to the victim cache to transmit a response including data obtained from the second address of the victim cache.

A data storage device may include a storage and a controller. The storage a storage including a first region of a first physical address range and a second region of a second physical address range. The controller may generate map data including a plurality of map segments, a first segment entry and a second segment entry, and store, in the second region, the map data except for a first map segment. Each of the map segments includes a set of physical addresses corresponding to a plurality of sequential logical addresses. The first segment entry includes a first segment physical address associated with the first map segment and belonging to the first physical address range, and the second segment entry includes a second segment physical address associated with a second map segment and belonging to the second physical address range.

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.

Systems, devices and methods are provided for operating a skewed-associative cache in a data processing system and, in particular, for changing address-to-row mappings in a skewed-associative cache.

Methods, apparatus, systems and articles of manufacture to facilitate an atomic operation and/or a histogram operation in cache pipeline are disclosed. An example system includes a cache storage coupled to an arithmetic component; and a cache controller coupled to the cache storage, wherein the cache controller is operable to: receive a memory operation that specifies a set of data; retrieve the set of data from the cache storage; utilize the arithmetic component to determine a set of counts of respective values in the set of data; generate a vector representing the set of counts; and provide the vector.