Patent classifications
G06F12/0888
Selectively writing back dirty cache lines concurrently with processing
A graphics pipeline includes a cache having cache lines that are configured to store data used to process frames in a graphics pipeline. The graphics pipeline is implemented using a processor that processes frames for the graphics pipeline using data stored in the cache. The processor processes a first frame and writes back a dirty cache line from the cache to a memory concurrently with processing of the first frame. The dirty cache line is retained in the cache and marked as clean subsequent to being written back to the memory. In some cases, the processor generates a hint that indicates a priority for writing back the dirty cache line based on a read command occupancy at a system memory controller.
Targeting of lateral castouts in a data processing system
A data processing system includes system memory and a plurality of processor cores each supported by a respective one of a plurality of vertical cache hierarchies. A first vertical cache hierarchy records information indicating communication of cache lines between the first vertical cache hierarchy and others of the plurality of vertical cache hierarchies. Based on selection of a victim cache line for eviction, the first vertical cache hierarchy determines, based on the recorded information, whether to perform a lateral castout of the victim cache line to another of the plurality of vertical cache hierarchies rather than to system memory and selects, based on the recorded information, a second vertical cache hierarchy among the plurality of vertical cache hierarchies as a recipient of the victim cache line via a lateral castout. Based on the determination, the first vertical cache hierarchy performs a castout of the victim cache line.
Targeting of lateral castouts in a data processing system
A data processing system includes system memory and a plurality of processor cores each supported by a respective one of a plurality of vertical cache hierarchies. A first vertical cache hierarchy records information indicating communication of cache lines between the first vertical cache hierarchy and others of the plurality of vertical cache hierarchies. Based on selection of a victim cache line for eviction, the first vertical cache hierarchy determines, based on the recorded information, whether to perform a lateral castout of the victim cache line to another of the plurality of vertical cache hierarchies rather than to system memory and selects, based on the recorded information, a second vertical cache hierarchy among the plurality of vertical cache hierarchies as a recipient of the victim cache line via a lateral castout. Based on the determination, the first vertical cache hierarchy performs a castout of the victim cache line.
Frozen time cache for multi-host read operations
Aspects of a storage device including a memory and a controller are provided. The controller may receive a prefetch request to retrieve data for a host having a promoted stream. The controller may access a frozen time table indicating hosts for which data has been prefetched and frozen times associated with the host and other hosts. The controller can determine whether the host has a higher priority over other hosts included in the frozen time table based on corresponding frozen times and data access parameters associated with the host. The controller may determine to prefetch the data for the host in response to the prefetch request when the host has a higher priority than the other hosts. The controller can receive a host read command associated with the promoted stream from the host and provide the prefetched data to the host in response to the host read command.
MEMORY TIERING TECHNIQUES IN COMPUTING SYSTEMS
Techniques of memory tiering in computing devices are disclosed herein. One example technique includes retrieving, from a first tier in a first memory, data from a data portion and metadata from a metadata portion of the first tier upon receiving a request to read data corresponding to a system memory section. The method can then include analyzing the data location information to determine whether the first tier currently contains data corresponding to the system memory section in the received request. In response to determining that the first tier currently contains data corresponding to the system memory section in the received request, transmitting the retrieved data from the data portion of the first memory to the processor in response to the received request. Otherwise, the method can include identifying a memory location in the first or second memory that contains data corresponding to the system memory section and retrieving the data from the identified memory location.
Dynamic allocation of cache memory as RAM
An apparatus includes a cache controller circuit and a cache memory circuit that further includes cache memory having a plurality of cache lines. The cache controller circuit may be configured to receive a request to reallocate a portion of the cache memory circuit that is currently in use. This request may identify an address region corresponding to one or more of the cache lines. The cache controller circuit may be further configured, in response to the request, to convert the one or more cache lines to directly-addressable, random-access memory (RAM) by excluding the one or more cache lines from cache operations.
Method and storage system with a layered caching policy
A storage system has volatile memory for use as a cache and can extend the available caching space by using a host memory buffer (HMB) in a host. However, because accesses to the HMB involve going through a host interface, there may be latencies in accessing the HMB, To reduce access latencies, the storage system views the volatile memory and the HMB as a two-level cache. In one use case, the storage system decides whether to store a logical-to-physical address table in the volatile memory or in the HMB based on a prediction of the likelihood that the table will be updated. If the likelihood for an update is above a threshold, the table is stored in the volatile memory, thereby eliminating the access latencies that would be encountered if the table needs to be updated and is stored in the HMB.
Method and apparatus for using a storage system as main memory
A data access system including a processor, multiple cache modules for the main memory, and a storage drive. The cache modules include a FLC controller and a main memory cache. The multiple cache modules function as main memory. The processor sends read/write requests (with physical address) to the cache module. The cache module includes two or more stages with each stage including a FLC controller and DRAM (with associated controller). If the first stage FLC module does not include the physical address, the request is forwarded to a second stage FLC module. If the second stage FLC module does not include the physical address, the request is forwarded to the storage drive, a partition reserved for main memory. The first stage FLC module has high speed, lower power operation while the second stage FLC is a low-cost implementation. Multiple FLC modules may connect to the processor in parallel.
Processor with reduced interrupt latency
A processor with reduced interrupt latency is disclosed. An apparatus includes a processor core and a cache subsystem having a cache controller and a cache. The processor core is configured to submit, to the cache controller, requests for access to the cache, wherein a given request for access to the cache specifies whether the given request is abandonable or non-abandonable in an event of an interrupt request. In response to a particular interrupt request, the processor core may provide an indication to cause the cache controller to abandon requests for access to the cache identified as abandonable. After receiving an acknowledgement from the cache controller that the abandonable requests have been abandoned, the processor core may begin execution of an interrupt handler in order to service the interrupt request.
Three tiered hierarchical memory systems
Systems, apparatuses, and methods related to three tiered hierarchical memory systems are described herein. A three tiered hierarchical memory system can leverage persistent memory to store data that is generally stored in a non-persistent memory, thereby increasing an amount of storage space allocated to a computing system at a lower cost than approaches that rely solely on non-persistent memory. An example apparatus may include a persistent memory, and one or more non-persistent memories configured to map an address associated with an input/output (I/O) device to an address in logic circuitry prior to the apparatus receiving a request from the I/O device to access data stored in the persistent memory, and map the address associated with the I/O device to an address in a non-persistent memory subsequent to the apparatus receiving the request and accessing the data.