Abstract: In one embodiment, the present invention includes a method for executing a transactional memory (TM) transaction in a first thread, buffering a block of data in a first buffer of a cache memory of a processor, and acquiring a write monitor on the block to obtain ownership of the block at an encounter time in which data at a location of the block in the first buffer is updated. Other embodiments are described and claimed.

Abstract: In one embodiment, the present invention includes a method for receiving control in a kernel mode via a ring transition from a user thread during execution of an unbounded transactional memory (UTM) transaction, updating a state of a transaction status register (TSR) associated with the user thread and storing the TSR with a context of the user thread, and later restoring the context during a transition from the kernel mode to the user thread. In this way, the UTM transaction may continue on resumption of the user thread. Other embodiments are described and claimed.

Abstract: Embodiments of the present invention provide a secure programming paradigm, and a protected cache that enable a processor to handle secret/private information while preventing, at the hardware level, malicious applications from accessing this information by circumventing the other protection mechanisms. A protected cache may be used as a building block to enhance the security of applications trying to create, manage and protect secure data. Other embodiments are described and claimed.

Abstract: Storing metadata that is disjoint from corresponding data by storing the metadata to the same address as the corresponding data but in a different address space. A metadata store instruction includes a storage address for the metadata. The storage address is the same address as that for data corresponding to the metadata, but the storage address when used for the metadata is implemented in a metadata address space while the storage address, when used for the corresponding data is implemented in a different data address space. As a result of executing the metadata store instruction, the metadata is stored at the storage address. A metadata load instruction includes the storage address for the metadata. As a result of executing the metadata load instruction, the metadata stored at the address is received. Some embodiments may further implement a metadata clear instruction which clears any entries in the metadata address space.

Abstract: Performing non-transactional escape actions within a hardware based transactional memory system. A method includes at a hardware thread on a processor beginning a hardware based transaction for the thread. Without committing or aborting the transaction, the method further includes suspending the hardware based transaction and performing one or more operations for the thread, non-transactionally and not affected by: transaction monitoring and buffering for the transaction, an abort for the transaction, or a commit for the transaction. After performing one or more operations for the thread, non-transactionally, the method further includes resuming the transaction and performing additional operations transactionally. After performing the additional operations, the method further includes either committing or aborting the transaction.

Abstract: Minimizing code duplication in an unbounded transactional memory system. A computing apparatus including one or more processors in which it is possible to use a set of common mode-agnostic TM barrier sequences that runs on legacy ISA and extended ISA processors, and that employs hardware filter indicators (when available) to filter redundant applications of TM barriers, and that enables a compiled binary representation of the subject code to run correctly in any of the currently implemented set of transactional memory execution modes, including running the code outside of a transaction, and that enables the same compiled binary to continue to work with future TM implementations which may introduce as yet unknown future TM execution modes.

Abstract: Operating system virtual memory management for hardware transactional memory. A method may be performed in a computing environment where an application running on a first hardware thread has been in a hardware transaction, with transactional memory hardware state in cache entries correlated by memory hardware when data is read from or written to data cache entries. The data cache entries are correlated to physical addresses in a first physical page mapped from a first virtual page in a virtual memory page table. The method includes an operating system deciding to unmap the first virtual page. As a result, the operating system removes the mapping of the first virtual page to the first physical page from the virtual memory page table. As a result, the operating system performs an action to discard transactional memory hardware state for at least the first physical page. Embodiments may further suspend hardware transactions in kernel mode.

Abstract: Synchronizing threads on loss of memory access monitoring. Using a processor level instruction included as part of an instruction set architecture for a processor, a read, or write monitor to detect writes, or reads or writes respectively from other agents on a first set of one or more memory locations and a read, or write monitor on a second set of one or more different memory locations are set. A processor level instruction is executed, which causes the processor to suspend executing instructions and optionally to enter a low power mode pending loss of a read or write monitor for the first or second set of one or more memory locations. A conflicting access is detected on the first or second set of one or more memory locations or a timeout is detected. As a result, the method includes resuming execution of instructions.

Abstract: Private or shared read-only memory regions. One embodiment may be practiced in a computing environment including a plurality of agents. A method includes acts for declaring one or more memory regions private to a particular agent or shared read only amongst agents by having software utilize processor level instructions to specify to hardware the private or shared read only memory address regions. The method includes an agent executing a processor level instruction to specify one or more memory regions as private to the agent or shared read-only amongst a plurality of agents. As a result of an agent executing a processor level instruction to specify one or more memory regions as private to the agent or shared read-only amongst a plurality of agents, a hardware component monitoring the one or more memory regions for conflicting accesses or prevents conflicting accesses on the one or more memory regions.

Abstract: A computing system includes a number of threads. The computing system is configured to allow for monitoring and testing memory blocks in a cache memory to determine effects on memory blocks by various agents. The system includes a processor. The processor includes a mechanism implementing an instruction set architecture including instructions accessible by software. The instructions are configured to: set per-hardware-thread, for a first thread, memory access monitoring indicators for a plurality of memory blocks, and test whether any monitoring indicator has been reset by the action of a conflicting memory access by another agent. The processor further includes mechanism configured to: detect conflicting memory accesses by other agents to the monitored memory blocks, and upon such detection of a conflicting access, reset access monitoring indicators corresponding to memory blocks having conflicting memory accesses, and remember that at least one monitoring indicator has been so reset.

Abstract: A method and apparatus for utilizing hardware mechanisms of a transactional memory system is herein described. Various embodiments relate to software-based filtering of operations from read and write barriers and read isolation barriers during transactional execution. Other embodiments relate to software-implemented read barrier processing to accelerate strong atomicity. Other embodiments are also described and claimed.

Abstract: A method and apparatus for metaphysical address space for holding lossy metadata is herein described. An explicit or implicit metadata access operation referencing data address of a data item is encountered. Hardware modifies the data address to a metadata address including a metaphysical extension. The metaphysical extension overlays one or more metaphysical address space(s) on the data address space. A portion of the metadata address including the metaphysical extension is utilized to search a tag array of the cache memory holding the data item. As a result, metadata access operations only hit metadata entries of the cache based on the metadata address extension. However, as the metadata is held within the cache, the metadata potentially competes with data for space within the cache.

Abstract: A method and apparatus for monitoring memory accesses in hardware to support transactional execution is herein described. Attributes are monitor accesses to data items without regard for detection at physical storage structure granularity, but rather ensuring monitoring at least at data items granularity. As an example, attributes are added to state bits of a cache to enable new cache coherency states. Upon a monitored memory access to a data item, which may be selectively determined, coherency states associated with the data item are updated to a monitored state. As a result, invalidating requests to the data item are detected through combination of the request type and the monitored coherency state of the data item.

Abstract: A method and apparatus for extending cache coherency to hold buffered data to support transactional execution is herein described. A transactional store operation referencing an address associated with a data item is performed in a buffered manner. Here, the coherency state associated with cache lines to hold the data item are transitioned to a buffered state. In response to local requests for the buffered data item, the data item is provided to ensure internal transactional sequential ordering. However, in response to external access requests, a miss response is provided to ensure the transactionally updated data item is not made globally visible until commit. Upon commit, the buffered lines are transitioned to a modified state to make the data item globally visible.

Abstract: A method and apparatus for registering a user-handler in hardware for transactional memory is herein described. A user-accessible register is to hold a reference to a transactional handler. An event register may also be provided to specify handler events, which may be done utilizing user-level software, privileged software, or by hardware. When an event is detected execution vectors to the transaction handler based on the reference to the transactional handler held in the user-accessible register. The transactional handler handles the event and then execution returns to normal flow.

Abstract: A method and apparatus for providing a memory model for hardware attributes to support transactional execution is herein described. Upon encountering a load of a hardware attribute, such as a test monitor operation to load a read monitor, write monitor, or buffering attribute, a fault is issued in response to a loss field indicating the hardware attribute has been lost. Furthermore, dependency actions, such as blocking and forwarding, are provided for the attribute access operations based on address dependency and access type dependency. As a result, different scenarios for attribute loss and testing thereof are allowed and restricted in a memory model.

Abstract: Controlling a reorder buffer (ROB) to selectively perform functional hardware lock disabling (HLD) is described. One apparatus embodiment includes a unit to enable an ROB to selectively disable a lock upon Identifying a lock acquire operation (LAO) associated with a critical section (CS) entry point, a unit to selectively retire the LAO, a unit to cause the ROB to selectively disable the lock, and a unit to snoop a buffer. The apparatus may, based on the snooping, selectively abort a transaction associated with the CS.

Abstract: Controlling a reorder buffer (ROB) to selectively perform functional hardware lock disabling (HLD) is described. One apparatus embodiment includes a unit to enable an ROB to selectively disable a lock upon Identifying a lock acquire operation (LAO) associated with a critical section (CS) entry point, a unit to selectively retire the LAO, a unit to cause the ROB to selectively disable the lock, and a unit to snoop a buffer. The apparatus may, based on the snooping, selectively abort a transaction associated with the CS.

Abstract: Method, apparatus, and program means for a programmable event driven yield mechanism that may activate other threads. In one embodiment, an apparatus includes execution resources to execute a plurality of instructions and an event detector to detect a long latency event associated with a synchronization object. The event detector can cause a first thread switch in response to the long latency event associated with the synchronization object. The apparatus may also include a spin detector to detect that the synchronization object is a contended synchronization object. The spin detector can cause a second thread switch in response to the detection of the contended synchronization object to enable a spin detect response.

Abstract: Methods, apparatus and systems for memory access obscuration are provided. A first embodiment provides memory access obscuration in conjunction with deadlock avoidance. Such embodiment utilizes processor features including an instruction to enable monitoring of specified cache lines and an instruction that sets a status bit responsive to any foreign access (e.g., write or eviction due to a read) to the specified lines. A second embodiment provides memory access obscuration in conjunction with deadlock detection. Such embodiment utilizes the monitoring feature, as well as handler registration. A user-level handler may be asynchronously invoked responsive to a foreign write to any of the specified lines. Invocation of the handler more frequently than expected indicates that a deadlock may have been encountered. In such case, a deadlock policy may be enforced. Other embodiments are also described and claimed.