# US 2013/0160020 A1 · Generational thread scheduler > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0160020 A1 - Document ID: US20130160020A1 - Status: Published application - Kind: A1 - Application number: 13/328,365 - Filed: 2011-12-16 - Published: 2013-06-20 - Earliest claimed: 2011-12-16 - Assignees: Intel Corporation - Inventors: Edward T. Grochowski; Michael D. Upton; George Z. Chrysos; Chunhui C. Zhang; Mohammed L. Al-Aqrabawi - Web page: https://patentgrep.com/patent/US20130160020A1 ## CPC - G06F 9/52: Program synchronisation; Mutual exclusion, e.g. by means of semaphores - G06F 2209/5014: Reservation - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract Disclosed herein is a generational thread scheduler. One embodiment may be used with processor multithreading logic to execute threads of executable instructions, and a shared resource to be allocated fairly among the threads of executable instructions contending for access to the shared resource. Generational thread scheduling logic may allocate the shared resource efficiently and fairly by granting a first requesting thread access to the shared resource allocating a reservation for the shared resource to each other requesting thread of the executing threads and then blocking the first thread from re-requesting the shared resource until every other thread that has been allocated a reservation, has been granted access to the shared resource. Generation tracking state may be cleared when each requesting thread of the generation that was allocated a reservation has had their request satisfied. ## Claims ### Claim 1 A method for sharing a resource in a multiprocessing system, the method comprising: receiving, from a first plurality of requesting entities in a processor, requests for a shared resource; granting a first entity of the first plurality of requesting entities access to the shared resource; allocating a reservation to other entities of the first plurality of requesting entities for the shared resource; and blocking the first entity from re-requesting the shared resource at least until each entity of the first plurality of requesting entities has been granted access to the shared resource. ### Claim 2 (depends on 1) The method of claim 1 further comprising: granting a second entity of the first plurality of requesting entities access to the shared resource; and blocking the second entity from re-requesting the shared resource at least until each entity of the first plurality of requesting entities has been granted access to the shared resource. ### Claim 3 (depends on 2) The method of claim 2 further comprising: allocating a reservation to each entity of a second plurality of requesting entities for the shared resource; and blocking the first and second entity from re-requesting the shared resource at least until each entity of the second plurality of requesting entities has been granted access to the shared resource. ### Claim 4 An article of manufacture comprising: a machine-accessible medium including data and instructions for allocating a shared resource among a plurality of entities such that, when accessed by a machine, cause the machine to: grant a first requesting entity of the plurality of entities access to the shared resource; allocate a reservation for the shared resource to each requesting entity of the first plurality of entities; and block the first entity from re-requesting the shared resource at least until no entity of the plurality of entities has been allocated a reservation but has not yet been granted access to the shared resource. ### Claim 5 (depends on 4) The article of manufacture of claim 4, said machine-accessible medium including data and instructions that, when accessed by a machine, cause the machine to: grant a second requesting entity of the plurality of entities access to the shared resource; and block the first and second entities from re-requesting the shared resource at least until there are none of the plurality of entities that, after being allocated a reservation, were not then granted access to the shared resource. ### Claim 6 (depends on 5) The article of manufacture of claim 5, said machine-accessible medium including data and instructions that, when accessed by a machine, cause the machine to: allocate a reservation for the shared resource to each requesting entity of the plurality of entities that has not already been granted access to the shared resource; and clear a first state variable when each entity of the plurality of entities that was allocated a reservation has had their request satisfied. ### Claim 7 A processor comprising: multithreading logic to execute a plurality of threads of executable instructions; a shared resource to be allocated fairly among threads of the plurality of threads of executable instructions contending for access to the shared resource; a thread scheduling logic to allocate the shared resource among the plurality of threads of executable instructions by: granting a first requesting thread of the plurality of threads of executable instructions access to the shared resource; allocating a reservation for the shared resource to requesting threads of the first plurality of threads of executable instructions; and blocking the first thread from re-requesting the shared resource at least until every thread of the plurality of threads of executable instructions that has been allocated a reservation, has had their request satisfied. ### Claim 8 (depends on 7) The processor of claim 7, said thread scheduling logic to further allocate the shared resource among the plurality of threads of executable instructions by: granting a second requesting thread of the plurality of threads of executable instructions access to the shared resource; and blocking the first and second thread from re-requesting the shared resource at least until every thread of the plurality of threads of executable instructions that has been allocated a reservation, has been granted access to the shared resource. ### Claim 9 (depends on 7) The processor of claim 7, said thread scheduling logic to further allocate the shared resource among the plurality of threads of executable instructions by: blocking all threads from re-requesting the shared resource until every thread of the plurality of threads of executable instructions that has been allocated a reservation, has been granted access to the shared resource. ### Claim 10 (depends on 7) The processor of claim 7, said thread scheduling logic to further allocate the shared resource among the plurality of threads of executable instructions by: allocating a reservation for the shared resource to each requesting thread of the plurality of threads of executable instructions that has not already been granted access to the shared resource; and clearing a first state variable for each thread of the plurality of threads of executable instructions that has been allocated a reservation if it has been granted access to the shared resource. ### Claim 11 (depends on 10) The processor of claim 10, said thread scheduling logic to further allocate the shared resource among the plurality of threads of executable instructions by: maintaining the first state variable for each thread of the plurality of threads of executable instructions having an outstanding or completed request, until every thread that has been allocated a reservation, has been granted access to the shared resource. ### Claim 12 A processor comprising: simultaneous multithreading logic to execute a plurality of threads of executable instructions; one or more cache memories to store a copy of one or more portions of data and/or executable instructions from an addressable memory, at least in part through the use of a shared resource; a finite-state machine for allocating the shared resource among the plurality of threads of executable instructions, said finite-state machine to: grant a first requesting thread of the plurality of threads of executable instructions access to the shared resource; allocate a reservation for the shared resource to requesting threads of the first plurality of threads of executable instructions; and block the first thread from re-requesting the shared resource at least until no thread of the plurality of threads of executable instructions has been allocated a reservation but has not been granted access to the shared resource. ### Claim 13 (depends on 12) The processor of claim 12, said finite-state machine to: block all threads from re-requesting the shared resource until every thread of the plurality of threads of executable instructions that has been allocated a reservation, has also been granted access to the shared resource. ### Claim 14 (depends on 12) The processor of claim 12, said finite-state machine to: allocate a reservation for the shared resource to each requesting thread that has not already been granted access to the shared resource; and clear a first state variable for each thread that has been allocated a reservation if it has been granted access to the shared resource. ### Claim 15 (depends on 14) The processor of claim 14, said finite-state machine to: maintain the first state variable for each thread having an outstanding or completed request, until every thread that has been allocated a reservation, has been granted access to the shared resource. ### Claim 16 A computing system comprising: an addressable memory to store data and also to store executable instructions; one or more cache memories to store a copy of one or more portions of the data and/or the executable instructions stored in the addressable memory, at least in part through the use of a shared resource; a multiprocessor including simultaneous multithreading logic to execute a plurality of threads of executable instructions, the multiprocessor operatively coupled with the addressable memory and including a finite-state machine for allocating the shared resource among the plurality of threads of executable instructions, said finite-state machine to: grant a first requesting thread of the plurality of threads of executable instructions access to the shared resource; allocate a reservation for the shared resource to requesting threads of the first plurality of threads of executable instructions; and block the first thread from re-requesting the shared resource at least until no thread of the plurality of threads of executable instructions has been allocated a reservation but has not yet been granted access to the shared resource. ### Claim 17 (depends on 16) The computing system of claim 16, said finite-state machine to: allocate a reservation for the shared resource to each requesting thread that has not already been granted access to the shared resource; and clear a first state variable for each thread that has been allocated a reservation if it has been granted access to the shared resource. ### Claim 18 (depends on 17) The computing system of claim 17, said finite-state machine to: maintain the first state variable for each thread having an outstanding or completed request, until every thread that has been allocated a reservation, has been granted access to the shared resource. ### Claim 19 (depends on 16) The computing system of claim 16, finite-state machine to: grant a second requesting thread of the plurality of threads of executable instructions access to the shared resource; and block the first and second thread from re-requesting the shared resource at least until every thread of the plurality of threads of executable instructions that has been allocated a reservation, has been granted access to the shared resource. ### Claim 20 (depends on 19) The computing system of claim 19, said finite-state machine to: block all threads from re-requesting the shared resource until every thread of the plurality of threads of executable instructions that has been allocated a reservation, has also been granted access to the shared resource.