Demote instruction for relinquishing cache line ownership
First Claim
Patent Images
1. A computer implemented method for relinquishing, by a selected processor, the selected processor'"'"'s own exclusive ownership of a specified cache line, the selected processor being a processor of a multi-processor system, the selected processor being an out-of-order processor comprising a pipeline, each processor of the multi-processor system communicatively coupled to a shared cache system, the method comprising:
- executing, by the selected processor, a demote instruction of a software program, the demote instruction specifying a logical address of a specified cache line, the executing the demote instruction by the selected processor comprising;
based on the demote instruction not being in an incorrectly predicted branch path of the selected processor and determining, by the computer system, that the specified cache line in the shared cache system is exclusively owned by the selected processor, relinquishing, by the computer system, the selected processor'"'"'s exclusive ownership of the cache line in the shared cache system; and
based on the demote instruction being in an incorrectly predicted branch path of the selected processor, not relinquishing, by the computer system, the selected processor'"'"'s exclusive ownership of the cache line in the shared cache system.
2 Assignments
0 Petitions
Accused Products
Abstract
A computer system processor of a multi-processor computer system having cache subsystem, executes a demote instruction to cause a cache line exclusively owned by the computer system processor to become shared or read-only in the cache subsystem.
-
Citations
21 Claims
-
1. A computer implemented method for relinquishing, by a selected processor, the selected processor'"'"'s own exclusive ownership of a specified cache line, the selected processor being a processor of a multi-processor system, the selected processor being an out-of-order processor comprising a pipeline, each processor of the multi-processor system communicatively coupled to a shared cache system, the method comprising:
-
executing, by the selected processor, a demote instruction of a software program, the demote instruction specifying a logical address of a specified cache line, the executing the demote instruction by the selected processor comprising; based on the demote instruction not being in an incorrectly predicted branch path of the selected processor and determining, by the computer system, that the specified cache line in the shared cache system is exclusively owned by the selected processor, relinquishing, by the computer system, the selected processor'"'"'s exclusive ownership of the cache line in the shared cache system; and based on the demote instruction being in an incorrectly predicted branch path of the selected processor, not relinquishing, by the computer system, the selected processor'"'"'s exclusive ownership of the cache line in the shared cache system. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
-
12. A computer implemented method for relinquishing, by a selected processor, the selected processor'"'"'s own exclusive ownership of a specified cache line, the selected processor being a processor of a multi-processor system, the selected processor being an out-of-order processor comprising a pipeline, each processor of the multi-processor system communicatively coupled to a shared cache system, the method comprising:
-
executing, by the selected processor, a demote instruction of a software program, the demote instruction specifying a logical address of a specified cache line, the executing the demote instruction by the selected processor comprising; based on older instructions, older than the demote instruction in the pipeline of the selected processor, successfully completing and the demote instruction not being in an incorrectly predicted branch path of the selected processor and determining, by the computer system, that the specified cache line in the shared cache system is exclusively owned by the selected processor, relinquishing, by the computer system, the selected processor'"'"'s exclusive ownership of the cache line in the shared cache system; and based on an older instruction, older than the demote instruction in the pipeline of the selected processor, not successfully completing due to pipeline flushing of the selected processor, not relinquishing, by the computer system, the selected processor'"'"'s exclusive ownership of the cache line in the shared cache system. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21)
-
Specification