International Business Machines Corporation

Thomas Basil Smith, Iii

Robert Brett Tremaine

Julian Satran

Leah Shalev

Zorik Machulsky

Ilan Shimony

Shmuel Ben-Yehuda

Ton Engbersen

Warren Edward Maule

Kevin Charles Gower

Jan Leonard Camenisch

Mark William Kellogg

Michael Waidner

Michael Backes

Patrick M Bland

Michael Edward Wazlowski

Maged M Michael

Eugen Schenfeld

Peter Anthony Franaszek

Alan Frederic Benner

Charles Otto Schulz

Antonius Paulus Engbersen

Ashwini K Nanda

Edi Shmueli

Michel Henri Theodore Hack

A method for facilitating direct memory access in a computing system in response to a request to transfer data is provided. The method comprises selecting a thread for transferring the data, wherein the thread executes on a processing core within the computing system; providing the thread with the request, wherein the request comprises information for carrying out a data transfer; and transferring the data according to the request. The method may further comprise: coordinating the request with a memory management unit, such that virtual addresses may be used to transfer data; invalidating a cache line associated with the source address or flushing a cache line associated with the destination address, if requested. Multiple threads can be selected to transfer data based on their proximity to the destination address.

Enhanced direct memory access

A computer-implemented system and method for protecting a memory are provided. The system includes a memory section with privileged and non-privileged sections, a host gateway (HG) to generate a capability credential, a device controller (DC) to append the credential to data transmitted to the memory, and at least one IO device enabled to do direct memory access (DMA) transactions with the memory.

Memory protection and security using credentials

Method and system for memory protection and security using credentials

A method and system for protection and security of IO devices using credential are provided. The system may include at least one consumer arranged to initiate IO requests from the IO device, and the IO requests may include IO capability allocation and additional parameters. The system may also include an IO resource manager (IORM) arranged to translate the IO capability allocation and additional parameters included in said IO request to a set of capability tokens for the consumer or for a group of consumers, to generate a global key to protect the capability tokens, and further arranged to manage the IO device. The system may further include a channel component arranged to transfer and receive the IO request to and from the IO device.

Method and system for protection and security of IO devices using credentials

A method for implementing a stream processing computer architecture includes creating a stream computer processing (SCP) system by forming a super node cluster of processors representing physical computation nodes ('nodes'), communicatively coupling the processors via a local interconnection means ('interconnect'), and communicatively coupling the cluster to an optical circuit switch (OCS), via optical external links (&#x201c;links&#x201d;). The OCS is communicatively coupled to another cluster of processors via the links. The method also includes generating a stream computation graph including kernels and data streams, and mapping the graph to the SCP system, which includes assigning the kernels to the clusters and respective nodes, assigning data stream traffic between the kernels to the interconnection when the data stream is between nodes in the same cluster, and assigning traffic between the kernels to the links when the data stream is between nodes in different clusters. The method also includes configuring the OCSs to provide connectivity between mapped clusters.

Stream processing in super node clusters of processors assigned with stream computation graph kernels and coupled by stream traffic optical links

A computer-implemented method for protecting a memory is provided. The method includes responsive to a direct memory access (DMA) request received from a consumer for a transaction of data from an IO device to the memory, the request including an IO command and a capability (CAP), generating a cryptographically signed capability (CAPB), forming a credential from CAP and CAPB, appending the credential to the IO command, configuring the IO device according to the credential and the IO command, transmitting the data from the IO device to the memory and prior to allowing execution of the DMA, authenticating that the credential is valid, further includes regenerating CAPB from a key available to an authenticating entity and from the CAP (included in CAPB) and verifying that the memory region information described in the cryptographically signed capability is the same as the requested region that was originally created, and that the cryptographically signed capability encompasses the IO command.

A system and method for unifying access to a physical memory by operations using virtual addresses of the same virtual address space are provided. The operations may be generated by at least one central processing unit (CPU operations) and/or by at least one IO device (IO operations). The system may include a bus arranged to transfer data and virtual addresses of the same virtual address space from the central processing unit (CPU) and the IO device to a unified memory management unit (UMMU), a unified memory management unit (UMMU) arranged to translate the virtual addresses to physical addresses, and to protect the physical memory from illegal access attempts of the CPU operations and the IO operations. The system may further include a memory controller arranged to manage access to the physical memory. The access is done by using physical addresses.

Method and system for unifying memory access for CPU and IO operations

A cascaded interconnect system including a memory controller, one or more memory modules, an upstream memory bus and a downstream memory bus. The one or more memory modules include a first memory module with cache data. The memory modules and the memory controller are interconnected by a packetized multi-transfer interface via the downstream memory bus and the upstream memory bus. The first memory module and the memory controller are in direct communication via the upstream memory bus and the downstream memory bus.

System, method and storage medium for providing data caching and data compression in a memory subsystem

An architecture, method and apparatus for a data processing system having memory compression and two common memories forming either a single unified memory, or a dual memory system capable of continuous operation in the presence of a hardware failure or redundant 'duplex' computer maintenance outage, without the cost of duplicating the memory devices. A memory controller employs hardware memory compression to reduce the memory requirement by half, which compensates for the doubling of the memory needed for the redundant storage. The memory controller employs error detection and correction code that is used to detect storage subsystem failure during read accesses. Upon detection of a fault, the hardware automatically reissues the read access to a separate memory bank that is logically identical to the faulty bank. After a memory bank is identified as faulty, the memory controller precludes further read access to the bank, permitting replacement without interruption to the application or operating system software operation.

Low cost and high RAS mirrored memory

A system and method of maintaining consistent cached copies of memory in a multiprocessor system having a main memory, includes a memory directory having entries mapping the main memory, an access history information in the memory directory entries, and a directory cache having records corresponding to a subset of the memory directory entries. The memory directory may be a full map directory having entries mapping all of the main memory or a sparse directory having entries mapping to a subset of the main memory. The method includes the steps of receiving a signal indicating a processor cache miss, retrieving a memory directory entry from the memory directory, updating the access history of the memory directory entry, selecting a directory cache line based on its access history and allocating the directory cache line for replacement, and writing the memory directory entry into the directory cache.

State-based allocation and replacement for improved hit ratio in directory caches

Memory is managed by controlling the expansion of memory contents, especially in those computing environments in which the memory contents are compressed. Control is provided by imposing some restrictions to memory references outside a specified subset of the memory contents, and by controlling the transfer of items into the subset. In one example, the transfer of items into the subset is based on a function of parameters, including an estimate of the amount of free space in the memory.

Space management in compressed main memory

An architecture, method and apparatus for a data processing system having memory compression and two common memories forming either a single unified memory, or a dual memory system capable of continuous operation in the presence of a hardware failure or redundant &ldquo;duplex&rdquo; computer maintenance outage, without the cost of duplicating the memory devices. A memory controller employs hardware memory compression to reduce the memory requirement by half, which compensates for the doubling of the memory needed for the redundant storage. The memory controller employs error detection and correction code that is used to detect storage subsystem failure during read accesses. Upon detection of a fault, the hardware automatically reissues the read access to a separate memory bank that is logically identical to the faulty bank. After a memory bank is identified as faulty, the memory controller precludes further read access to the bank, permitting replacement without interruption to the application or operating system software operation.

In a cache memory system, a mechanism enabling two logical cache lines to coexist within the same physical cache line, during line fill and replacement, thus minimizing the likelihood of stalling accesses to the cache while the line is being filled or replaced. A control mechanism governs access to the cache line and tracks which sub-cache line units contain old or new data, or are empty during the fill/replacement procedure. The control mechanism thus maintains a sub-cache line state for the purpose of permitting a processor to gain access to a portion of the cache line before it is completely filled or replaced.

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Wilton, CT, United States of America

Thomas Basil Smith, Iii