International Business Machines Corporation

Globalfoundries Inc.

Lenovo (singapore) Pte. Ltd.

Manoj Dusanapudi

Shakti Kapoor

Sunil Suresh Hatti

Nelson Wu

Vinod Bussa

Shubhodeep Roy Choudhury

Madhusudan Kadiyala

Sampan Arora

Prasanna Jayaraman

Sandip Bag

Bhavani Shringari Nanjundiah

Rahul Sharad Moharil

Batchu Naga Venkata Satyanarayana

John Paul

Anil Bindu Lingambudi

John Andrew Schumann

Varun Mallikarjunan

Sairam Kamaraju

Divya S Anvekar

Timothy Jay Dell

Paul Frank Lecocq

Chakrapani Rayadurgam

Saravanan Sethuraman

Anil Krishna

Girisankar Paulraj

Rahul Rao

Amir Nahir

Vitali Sokhin

Diyanesh B Vidyapoornachary

Narasimha R Adiga

Gil Eliezer Shurek

Wisam Kadry

Subrat K Panda

Shimon Landa

Shiraz Mohammad Zaman

Siva Sundar A

Bhavesh Dhanji Budhabhatti

Dimtry Krestyashyn

Brenton Yiu

Nandhini Rajaiah

Sai Rupak Mohanan

A system, mechanism, tool, programming product, processor, and/or method for generating a hazard in a processor includes: identifying one or more cache lines to invalidate in a second level memory of a processing core in the processor; invalidating, in response to identifying one or more cache lines to invalidate in the second level cache, the one or more identified cache lines in the second level memory; and invalidating, in response to invalidating the one or more identified cache lines in the second level memory, the corresponding one or more cache lines in a first level memory. In an aspect the hazard generating mechanism is triggered, preferably on demand, and includes in an approach searching for cache lines in the second level memory that are also in the first level memory.

Hazard generating for speculative cores in a microprocessor

Provided is a processor that includes a load and store unit (LSU) and a cache memory, and transfers data information from a store queue in the LSU to the cache memory. The cache memory requests an information packet from the LSU when the cache memory determines that an available entry exists in a store queue within the cache memory. The LSU acknowledges the request and transfers an information packet to the cache memory. The LSU anticipates that an additional available entry exists in the cache memory, transmits an additional acknowledgement to the cache memory, and transfers an additional information packet, before receiving an additional request from the cache memory.

Performance and reliability of processor store operation data transfers

Systems and methods for invalidating page translation entries are described. A processing element may apply a delay to a drain cycle of a store reorder queue (SRQ) of a processing element. The processing element may drain the SRQ under the delayed drain cycle. The processing element may receive a translation lookaside buffer invalidation (TLBI) instruction from an interconnect connecting the plurality of processing elements. The TLBI instruction may be an instruction to invalidate a translation lookaside buffer (TLB) entry corresponding to at least one of a virtual memory page and a physical memory frame. The TLBI instruction may be broadcasted by another processing element. The application of the delay to the drain cycle of the SRQ may decrease a difference between the drain cycle of the SRQ and an invalidation cycle associated with the TLBI.

Validation of store coherence relative to page translation invalidation

Methods and systems for validating cache coherence in a data processing system are described. A processing element may detect a load instruction requesting the processing element to transfer data from a global memory location to a local memory location. The processing element may apply, in response to detecting the load instruction requesting the processing element to transfer data from the global memory location to the local memory location, a delay to the transfer of the data from the global memory location to the local memory location. The processing element may execute the load instruction and transferring the data from the global memory location to the local memory location with the applied delay. The processing element may validate, in response to executing the load instruction and transferring the data with the applied delay, a cache coherence of the data processing system.

Cache coherence validation using delayed fulfillment of L2 requests

Test case generation for a hardware state space including: identifying, from a first test case comprising a first plurality of test operations executed by a processor comprising a first configuration, a test operation causing an invalid result; determining a functional path associated with the test operation; generating a second plurality of test operations based on the functional path; generating a processor state by executing, by the processor comprising a second configuration, a subset of the first plurality of test operations comprising the determined test operation; and generate a second test case comprising the second plurality of test operations configured for execution based on the processor state.

Test case generation for a hardware state space

A processor memory is stress tested with a variable list insertion depth using list insertion test segments with non-naturally aligned data boundaries. List insertion test segments are interspersed into test code of a processor memory tests to change the list insertion depth without changing results of the test code. The list insertion test segments are the same structure as the segments of the test code and have non-naturally aligned boundaries. The list insertion test segments include list insertion segments and load/store segments. The list insertion segments locate a current memory location using a fixed segment at a known location. The load/store segments load and store list elements in memory.

List insertion in test segments with non-naturally aligned data boundaries

Disclosed is a system, method and/or computer product that includes generating translation requests that are identical but have different expected results, transmitting the translation requests from a MMU tester to a non-core MMU disposed on a processor chip, where the non-core MMU is external to a processing core of the processor chip, and where the MMU tester is disposed on a computing component external to the processor chip. The method also includes receiving memory translation results from the non-core MMU at the MMU tester, comparing the results to determine if there is a flaw in the non-core MMU.

Method, system, and apparatus for stress testing memory translation tables

A processor memory is stress tested with a variable link stack depth using test code segments and link stack test segments on non-naturally aligned data boundaries. Link stack test segments are interspersed into test code segments of a processor memory test to change the link stack depth without changing results of the test code. The link stack test segments include branch to target, push/pop, push and pop segments. The depth of the link stack is varied independent of the memory test code by changing the number to branches in the branch to target segment and varying the number of the push/pop segments. The link stack test segments and test segments may be placed randomly with a recursive algorithm to intersperse the link stack test segments in the test code segments and to reduce the amount of data to be saved and restored for all subroutine calls, push and pop segments.

Controlling segment layout in a stress test for a processor memory with a link stack

A method, executed by a computer, includes pairing a first core with a second core to form a first core group, wherein each core of the group has a plurality of functional units, transferring instructions received by the first core to the second core for execution via a first inter-core communication bus, and executing the instructions on the second core. A computer system and computer program product corresponding to the above method are also disclosed herein.

Core pairing in multicore systems

A system comprising a computer processor comprising a plurality of registers, a load-store unit configured to load data in at least one of the plurality of registers, and a memory. The memory includes a memory location mapped to a first virtual memory address and a second virtual memory address. Issuance of a load from the memory location via the first virtual memory address causes execution of a side effect. The memory also includes a computer program containing programming instructions that, when executed by the computer processor, performs an operation that includes storing a predetermined data value at the memory location, and testing the memory for errors during load operations.

System and method for testing processor errors

Efficiently generating effective address translations for memory management test cases including obtaining a first set of EAs, wherein each EA comprises an effective segment ID and a page, wherein each effective segment ID of each EA in the first set of EAs is mapped to a same first effective segment; obtaining a set of virtual address corresponding to the first set of EAs; translating the first set of EAs by applying a hash function to each virtual address in the set of virtual addresses to obtain a first set of PTEG addresses mapped to a first set of PTEGs; and generating a translation for a second set of EAs to obtain a second set of PTEG addresses mapped to the first set of PTEGs.

Efficiently generating effective address translations for memory management test cases

A processor memory is stress tested with a variable link stack depth using link stack test segments with non-naturally aligned data boundaries. Link stack test segments are interspersed into test code of a processor memory tests to change the link stack depth without changing results of the test code. The link stack test segments are the same structure as the segments of the test code and have non-naturally aligned boundaries. The link stack test segments include branch to target, push/pop, push and pop segments. The depth of the link stack is varied independent of the memory test code by changing the number to branches in the branch to target segment and varying the number of the push/pop segments.

Stress testing a processor memory with a link stack

A circuit and method provide efficient stress testing of address translations in an integrated circuit such as a link processing unit. A random DMA mode (RDM) circuit provides a random input to index into a translation validation table (TVT) that is used to generate the real memory address. The RDM circuit allows testing all entries of the TVT, and thus all DMA modes, regardless of what bus agents are connected to the link processing unit. The RDM circuit may use a multiplexer to select between a runtime input and a random test input provided by the random bit generator. When the link processing unit is in a test mode a mode selection bit is asserted to select the random test input.

Efficient testing of direct memory address translation

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Bengaluru, India

Manoj Dusanapudi