公开(公告)号：US20140201507A1

公开(公告)日：2014-07-17

申请号：US13739161

申请日：2013-01-11

Applicant: ADVANCED MICRO DEVICES, INC.

Inventor： Ramkumar Jayaseelan ,  Ravindra N. Bhargava

IPC: G06F9/38

CPC classification number: G06F9/3844 ,  G06F9/3848 ,  G06F9/3851

Abstract: A processor employs one or more branch predictors to issue branch predictions for each thread executing at an instruction pipeline. Based on the branch predictions, the processor determines a branch prediction confidence for each of the executing threads, whereby a lower confidence level indicates a smaller likelihood that the corresponding thread will actually take the predicted branch. Because speculative execution of an untaken branch wastes resources of the instruction pipeline, the processor prioritizes threads associated with a higher confidence level for selection at the stages of the instruction pipeline.

Abstract translation: 处理器使用一个或多个分支预测器来为在指令流水线上执行的每个线程发出分支预测。 基于分支预测，处理器确定每个执行线程的分支预测置信度，由此较低的置信水平表示相应线程实际上将采取预测分支的可能性较小。 由于非笔记本分支的推测执行浪费了指令流水线的资源，所以处理器将与更高置信水平相关联的线程优先排列，以在指令流水线的阶段进行选择。

公开(公告)号：US20220404978A1

公开(公告)日：2022-12-22

申请号：US17895357

申请日：2022-08-25

Applicant: Advanced Micro Devices, Inc.

Inventor： Ravindra N. Bhargava ,  Philip S. Park ,  Vydhyanathan Kalyanasundharam ,  James Raymond Magro

IPC: G06F3/06 ,  G06F13/16 ,  G06F9/52

Abstract: Systems, apparatuses, and methods for performing efficient memory accesses for a computing system are disclosed. In various embodiments, a computing system includes a computing resource and a memory controller coupled to a memory device. The computing resource selectively generates a hint that includes a target address of a memory request generated by the processor. The hint is sent outside the primary communication fabric to the memory controller. The hint conditionally triggers a data access in the memory device. When no page in a bank targeted by the hint is open, the memory controller processes the hint by opening a target page of the hint without retrieving data. The memory controller drops the hint if there are other pending requests that target the same page or the target page is already open.

公开(公告)号：US11526278B2

公开(公告)日：2022-12-13

申请号：US15851414

申请日：2017-12-21

Applicant: Advanced Micro Devices, Inc.

Inventor： Guanhao Shen ,  Ravindra N. Bhargava ,  James Raymond Magro ,  Kedarnath Balakrishnan ,  Kevin M. Brandl

IPC: G06F3/06

Abstract: Systems, apparatuses, and methods for performing efficient memory accesses for a computing system are disclosed. In various embodiments, a computing system includes one or more computing resources and a memory controller coupled to a memory device. The memory controller determines a memory access request targets a given bank of multiple banks. An access history is updated for the given bank based on whether the memory access request hits on an open page within the given bank and a page hit rate for the given bank is determined. The memory controller sets an idle cycle limit based on the page hit rate. The idle cycle limit is a maximum amount of time the given bank will be held open before closing the given bank while the bank is idle. The idle cycle limit is based at least in part on a page hit rate for the bank.

公开(公告)号：US11119926B2

公开(公告)日：2021-09-14

申请号：US15846008

申请日：2017-12-18

Applicant: Advanced Micro Devices, Inc.

Inventor： Vydhyanathan Kalyanasundharam ,  Kevin M. Lepak ,  Amit P. Apte ,  Ganesh Balakrishnan ,  Eric Christopher Morton ,  Elizabeth M. Cooper ,  Ravindra N. Bhargava

IPC: G06F12/0817 ,  G06F12/128 ,  G06F12/0811 ,  G06F12/0871 ,  G06F12/0831

Abstract: Systems, apparatuses, and methods for maintaining a region-based cache directory are disclosed. A system includes multiple processing nodes, with each processing node including a cache subsystem. The system also includes a cache directory to help manage cache coherency among the different cache subsystems of the system. In order to reduce the number of entries in the cache directory, the cache directory tracks coherency on a region basis rather than on a cache line basis, wherein a region includes multiple cache lines. Accordingly, the system includes a region-based cache directory to track regions which have at least one cache line cached in any cache subsystem in the system. The cache directory includes a reference count in each entry to track the aggregate number of cache lines that are cached per region. If a reference count of a given entry goes to zero, the cache directory reclaims the given entry.

公开(公告)号：US20190196996A1

公开(公告)日：2019-06-27

申请号：US15851087

申请日：2017-12-21

Applicant: Advanced Micro Devices, Inc.

Inventor： Kedarnath Balakrishnan ,  Ravindra N. Bhargava ,  Guanhao Shen ,  James Raymond Magro ,  Kevin M. Brandl

IPC: G06F13/30 ,  G06F13/16 ,  G06F3/06

CPC classification number: G06F13/30 ,  G06F3/061 ,  G06F3/0659 ,  G06F13/1642 ,  G06F13/1668

Abstract: Systems, apparatuses, and methods for performing efficient memory accesses for a computing system are disclosed. When a memory controller in a computing system determines a threshold number of memory read requests have been sent to a memory device in a read mode of a data bus, the memory controller determines a threshold number of memory write requests to send to the memory device in an upcoming write mode is a number of outstanding memory write requests. Alternatively, the memory controller determines the threshold number of memory write requests to send to the memory device in an upcoming write mode is a maximum value of the number of outstanding memory write requests and a programmable value of the write burst length stored in a control register. Therefore, the write burst length is determined dynamically. Similarly, the read burst length is determined dynamically when the write mode ends.

公开(公告)号：US20190196987A1

公开(公告)日：2019-06-27

申请号：US15851324

申请日：2017-12-21

Applicant: Advanced Micro Devices, Inc.

Inventor： Guanhao Shen ,  Ravindra N. Bhargava ,  James Raymond Magro ,  Kedarnath Balakrishnan ,  Jing Wang

IPC: G06F13/16 ,  G06F13/42

CPC classification number: G06F13/1636 ,  G06F13/1642 ,  G06F13/4234 ,  G11C11/40603

Abstract: Systems, apparatuses, and methods for performing efficient memory accesses in a computing system are disclosed. In various embodiments, a computing system includes computing resources and a memory controller coupled to a memory device. The memory controller determines a memory request targets a given rank of multiple ranks. The memory controller determines a predicted latency for the given rank as an amount of time the pending queue in the memory controller for storing outstanding memory requests does not store any memory requests targeting the given rank. The memory controller determines the total bank latency as an amount of time for refreshing a number of banks which have not yet been refreshed in the given rank with per-bank refresh operations. If there are no pending requests targeting the given rank, each of the predicted latency and the total bank latency is used to select between per-bank and all-bank refresh operations.

公开(公告)号：US20190196720A1

公开(公告)日：2019-06-27

申请号：US15851414

申请日：2017-12-21

Applicant: Advanced Micro Devices, Inc.

Inventor： Guanhao Shen ,  Ravindra N. Bhargava ,  James Raymond Magro ,  Kedarnath Balakrishnan ,  Kevin M. Brandl

IPC: G06F3/06

CPC classification number: G06F3/0611 ,  G06F3/0653 ,  G06F3/0658 ,  G06F3/0673

Abstract: Systems, apparatuses, and methods for performing efficient memory accesses for a computing system are disclosed. In various embodiments, a computing system includes one or more computing resources and a memory controller coupled to a memory device. The memory controller determines a memory access request targets a given bank of multiple banks. An access history is updated for the given bank based on whether the memory access request hits on an open page within the given bank and a page hit rate for the given bank is determined. The memory controller sets an idle cycle limit based on the page hit rate. The idle cycle limit is a maximum amount of time the given bank will be held open before closing the given bank while the bank is idle. The idle cycle limit is based at least in part on a page hit rate for the bank.

公开(公告)号：US20190179760A1

公开(公告)日：2019-06-13

申请号：US15839700

申请日：2017-12-12

Applicant: Advanced Micro Devices, Inc.

Inventor： Ravindra N. Bhargava ,  Ganesh Balakrishnan

IPC: G06F12/0864 ,  G06F12/0897 ,  G06F12/0895

Abstract: Systems, apparatuses, and methods for performing efficient memory accesses for a computing system are disclosed. External system memory is used as a last-level cache and includes one of a variety of types of dynamic random access memory (DRAM). A memory controller generates a tag request and a separate data request based on a same, single received memory request. The sending of the tag request is prioritized over sending the data request. A partial tag comparison is performed during processing of the tag request. If a tag miss is detected for the partial tag comparison, then the data request is cancelled, and the memory request is sent to main memory. If one or more tag hits are detected for the partial tag comparison, then processing of the data request is dependent upon the result of the full tag comparison.

公开(公告)号：US11874774B2

公开(公告)日：2024-01-16

申请号：US17031834

申请日：2020-09-24

Applicant: Advanced Micro Devices, Inc.

Inventor： Ravindra N. Bhargava ,  Ganesh Balakrishnan ,  Joe Sargunaraj ,  Chintan S. Patel ,  Girish Balaiah Aswathaiya ,  Vydhyanathan Kalyanasundharam

IPC: G06F12/08 ,  G06F12/0891 ,  G06F9/46 ,  G06F12/0813 ,  G06F12/0831 ,  G06F12/084

CPC classification number: G06F12/0891 ,  G06F9/467 ,  G06F12/084 ,  G06F12/0813 ,  G06F12/0833

Abstract: A method includes, in response to each write request of a plurality of write requests received at a memory-side cache device coupled with a memory device, writing payload data specified by the write request to the memory-side cache device, and when a first bandwidth availability condition is satisfied, performing a cache write-through by writing the payload data to the memory device, and recording an indication that the payload data written to the memory-side cache device matches the payload data written to the memory device.

公开(公告)号：US11809322B2

公开(公告)日：2023-11-07

申请号：US17472977

申请日：2021-09-13

Applicant: Advanced Micro Devices, Inc.

Inventor： Vydhyanathan Kalyanasundharam ,  Kevin M. Lepak ,  Amit P. Apte ,  Ganesh Balakrishnan ,  Eric Christopher Morton ,  Elizabeth M. Cooper ,  Ravindra N. Bhargava

IPC: G06F12/0817 ,  G06F12/128 ,  G06F12/0811 ,  G06F12/0871 ,  G06F12/0831

CPC classification number: G06F12/0817 ,  G06F12/0811 ,  G06F12/0831 ,  G06F12/0871 ,  G06F12/128 ,  G06F2212/283 ,  G06F2212/604 ,  G06F2212/621

Abstract: Systems, apparatuses, and methods for maintaining a region-based cache directory are disclosed. A system includes multiple processing nodes, with each processing node including a cache subsystem. The system also includes a cache directory to help manage cache coherency among the different cache subsystems of the system. In order to reduce the number of entries in the cache directory, the cache directory tracks coherency on a region basis rather than on a cache line basis, wherein a region includes multiple cache lines. Accordingly, the system includes a region-based cache directory to track regions which have at least one cache line cached in any cache subsystem in the system. The cache directory includes a reference count in each entry to track the aggregate number of cache lines that are cached per region. If a reference count of a given entry goes to zero, the cache directory reclaims the given entry.