In one embodiment of the present invention, a method includes switching between a first address space and a second address space, determining if the second address space exists in a list of address spaces; and maintaining entries of the first address space in a translation buffer after the switching. In such manner, overhead associated with such a context switch may be reduced.

Systems, methods, and apparatuses relating to circuitry to implement precise last branch record event logging in a processor are described. In one embodiment, a hardware processor core includes an execution circuit to execute instructions, a retirement circuit to retire executed instructions, a status register, and a last branch record circuit to, in response to retirement by the retirement circuit of a first taken branch instruction, start a cycle timer and a performance monitoring event counter, and in response to retirement by the retirement circuit of a second taken branch instruction, that is a next taken branch instruction in program order after the first taken branch instruction, write values from the cycle timer and the performance monitoring event counter into a first entry in the status register and clear the values from the cycle timer and the performance monitoring event counter.

Techniques that facilitate hybrid memory access frequency are provided. In one example, a system stores access frequency data for storage class memory and volatile memory in a translation lookaside buffer. The access frequency data is indicative of a frequency of access to the storage class memory and the volatile memory. The system also determines whether to store data in the storage class memory or the volatile memory based on the access frequency data stored in the translation lookaside buffer.

A method for operating translation look-aside buffers, TLBs, in a multiprocessor system. A purge request is received for purging one or more entries in the TLB. When the thread doesn't require access to the entries to be purged the execution of the purge request at the TLB may start. When an address translation request is rejected due to the TLB purge, a suspension time window may be set. During the suspension time window, the execution of the purge is suspended and address translation requests of the thread are executed. After the suspension window is ended the purge execution may be resumed. When the thread requires access to the entries to be purged, it may be blocked for preventing the thread sending address translation requests to the TLB and upon ending the purge request execution, the thread may be unblocked and the address translation requests may be executed.

A method, apparatus, and system for reducing pipeline stalls due to address translation misses is presented. An apparatus comprises a memory access instruction pipeline, a translation lookaside buffer coupled to the memory access instruction pipeline, and a TLB miss queue coupled to both the TLB and the memory access instruction pipeline. The TLB miss queue is configured to selectively store a first memory access instruction that has been removed from the memory access instruction pipeline as a result of the first memory access instruction missing in the TLB along with information associated with the first memory access instruction. The TLB miss queue is further configured to reintroduce the first memory access instruction to the memory access instruction pipeline associated with a return of an address translation related to the first memory access instruction.

In one embodiment of the present invention, a method includes switching between a first address space and a second address space, determining if the second address space exists in a list of address spaces; and maintaining entries of the first address space in a translation buffer after the switching. In such manner, overhead associated with such a context switch may be reduced.

A method for operating translation look-aside buffers, TLBs, in a multiprocessor system. A purge request is received for purging one or more entries in the TLB. When the thread doesn't require access to the entries to be purged the execution of the purge request at the TLB may start. When an address translation request is rejected due to the TLB purge, a suspension time window may be set. During the suspension time window, the execution of the purge is suspended and address translation requests of the thread are executed. After the suspension window is ended the purge execution may be resumed. When the thread requires access to the entries to be purged, it may be blocked for preventing the thread sending address translation requests to the TLB and upon ending the purge request execution, the thread may be unblocked and the address translation requests may be executed.

Techniques that facilitate hybrid memory access frequency are provided. In one example, a system stores access frequency data for storage class memory and volatile memory in a translation lookaside buffer. The access frequency data is indicative of a frequency of access to the storage class memory and the volatile memory. The system also determines whether to store data in the storage class memory or the volatile memory based on the access frequency data stored in the translation lookaside buffer.

Techniques that facilitate hybrid memory access frequency are provided. In one example, a system stores access frequency data for storage class memory and volatile memory in a translation lookaside buffer. The access frequency data is indicative of a frequency of access to the storage class memory and the volatile memory. The system also determines whether to store data in the storage class memory or the volatile memory based on the access frequency data stored in the translation lookaside buffer.

A method, apparatus, and system for reducing pipeline stalls due to address translation misses is presented. An apparatus comprises a memory access instruction pipeline, a translation lookaside buffer coupled to the memory access instruction pipeline, and a TLB miss queue coupled to both the TLB and the memory access instruction pipeline. The TLB miss queue is configured to selectively store a first memory access instruction that has been removed from the memory access instruction pipeline as a result of the first memory access instruction missing in the TLB along with information associated with the first memory access instruction. The TLB miss queue is further configured to reintroduce the first memory access instruction to the memory access instruction pipeline associated with a return of an address translation related to the first memory access instruction.