System and method for providing forward progress and avoiding starvation and livelock in a multiprocessor computer system
원문보기
IPC분류정보
국가/구분
United States(US) Patent
등록
국제특허분류(IPC7판)
G06F-013/36
G06F-013/00
G06F-012/00
출원번호
US-0652984
(2000-08-31)
발명자
/ 주소
Duncan, Samuel H.
Ho, Steven
출원인 / 주소
Hewlett-Packard Development Company, L.P.
인용정보
피인용 횟수 :
23인용 특허 :
9
초록▼
A system and method avoids "livelock" and "starvation" among two or more input/output (I/O) devices of a symmetrical multiprocessor (SMP) computer system competing for the same data. The SMP computer system includes a plurality of interconnected processors, one or more memories that are shared by th
A system and method avoids "livelock" and "starvation" among two or more input/output (I/O) devices of a symmetrical multiprocessor (SMP) computer system competing for the same data. The SMP computer system includes a plurality of interconnected processors, one or more memories that are shared by the processors, and a plurality of I/O bridges to which the I/O devices are coupled. A cache coherency protocol is executed the I/O bridges, which requires the I/O bridges to obtain "exclusive" (not shared) ownership of all data stored by the bridges. In response to a request for data currently stored by an I/O bridge, the bridge first copies at least a portion of that data to a non-coherent buffer before invalidating the data. The bridge then takes the largest amount of the data saved in its non-coherent buffer that its knows to be coherent, and releases only that known coherent amount to the I/O device, and then discards all of the saved data.
대표청구항▼
A system and method avoids "livelock" and "starvation" among two or more input/output (I/O) devices of a symmetrical multiprocessor (SMP) computer system competing for the same data. The SMP computer system includes a plurality of interconnected processors, one or more memories that are shared by th
A system and method avoids "livelock" and "starvation" among two or more input/output (I/O) devices of a symmetrical multiprocessor (SMP) computer system competing for the same data. The SMP computer system includes a plurality of interconnected processors, one or more memories that are shared by the processors, and a plurality of I/O bridges to which the I/O devices are coupled. A cache coherency protocol is executed the I/O bridges, which requires the I/O bridges to obtain "exclusive" (not shared) ownership of all data stored by the bridges. In response to a request for data currently stored by an I/O bridge, the bridge first copies at least a portion of that data to a non-coherent buffer before invalidating the data. The bridge then takes the largest amount of the data saved in its non-coherent buffer that its knows to be coherent, and releases only that known coherent amount to the I/O device, and then discards all of the saved data. ixing device according to claim 1, wherein the thermal cutoff device is provided proximate the roller. 9. The thermal fixing device according to claim 2, wherein the plurality of thermal cutoff devices are disposed on a circumference about an axis of the roller in alignment with positions identical in temperature in the temperature distribution. 10. The thermal fixing device according to claim 2, wherein the temperature sensor and at least one of the plurality of thermal cutoff devices are disposed on the same plane including an axis of the roller. 11. The thermal fixing device according to claim 2, wherein each of the plurality of thermal cutoff devices has a temperature sensing element that senses a temperature, and each temperature sensing element is disposed facing the surface of the roller in alignment with a position spaced by a predetermined distance, in the axial direction of the roller from the temperature distribution center. 12. The thermal fixing device according to claim 2, wherein different types of thermal cutoff devices are provided as the thermal cutoff device. 13. The thermal fixing device according to claim 9, wherein the temperature sensor and at least one of the plurality of thermal cutoff devices are disposed on the same plane including the axis of the roller. 14. The thermal fixing device according to claim 9, wherein each of the plurality of thermal cutoff devices has a temperature sensing element that senses a temperature, and each temperature sensing element is disposed facing the surface of the roller in alignment with a position spaced by a predetermined distance, in the axial direction of the roller from the temperature distribution center. 15. The thermal fixing device according to claim 9, wherein different types of thermal cutoff devices are provided as the thermal cutoff device. 16. The thermal fixing device according to claim 13, wherein each of the plurality of thermal cutoff devices has a temperature sensing element that senses a temperature, and each temperature sensing element is disposed facing the surface of the roller in alignment with a position spaced by a predetermined distance, in the axial direction of the roller from the temperature distribution center. 17. The thermal fixing device according to claim 13, wherein different types of thermal cutoff devices are provided as the thermal cutoff device. 18. The thermal fixing device according to claim 16, wherein different types of thermal cutoff devices are provided as the thermal cutoff device. 19. A thermal fixing device, comprising: a roller; a heater that heats the roller; a temperature sensor provided proximate the roller to sense a temperature of the roller; and a thermal cutoff device provided proximate the roller to interrupt power supply to the heater, wherein the temperature sensor and the thermal cutoff device are disposed symmetrically with respect to an axial center of the roller, and are coplanar with the axial center of the roller. 20. A thermal fixing device, comprising: a roller; a heater that heats the roller; a temperature sensor provided proximate the roller to sense a temperature of the roller; and a plurality of thermal cutoff devices proximate the roller to interrupt power supply to the heater, wherein the plurality of thermal cutoff devices are disposed on the same circumference about an axis of the roller. 21. The thermal fixing device according to claim 20, wherein the heater is provided inside the roller in the axial direction of the roller. 22. An image forming device that forms a toner image on a recording medium, comprising: a thermal fixing device that heats and presses the recording medium having the toner image to fix the toner image onto the recording medium, the thermal fixing device comprising: a roller; a heater that heats the roller; a temperature sensor provided proximate the roller to sense a temperature of the roller; and a thermal cutoff device provided proximate the rol ler to interrupt power supply to the heater, wherein the heater has a temperature distribution that is symmetrical in an axial direction of the roller with respect to a temperature distribution center, and the temperature sensor and the thermal cutoff device are disposed facing a surface of the roller in alignment with symmetrical positions spaced by a predetermined distance, in the axial direction of the roller from the temperature distribution center. 23. An image forming device that forms a toner image on a recording medium, comprising: a thermal fixing device that heats and presses the recording medium having the toner image to fix the toner image onto the recording medium, the thermal fixing device comprising: a roller; a heater that heats the roller; a temperature sensor provided proximate the roller to sense a temperature of the roller; and a thermal cutoff device provided proximate the roller to interrupt power supply to the heater, wherein the temperature sensor and the thermal cutoff device are disposed symmetrically with respect to an axial center of the roller, and are coplanar with the axial center of the roller. 24. An image forming device that forms a toner image on a recording medium, comprising: a thermal fixing device that heats and presses the recording medium having the toner image to fix the toner image onto the recording medium, the thermal fixing device comprising: a roller; a heater that heats the roller; a temperature sensor provided proximate the roller to sense a temperature of the roller; and a plurality of thermal cutoff devices provided proximate the roller to interrupt power supply to the heater, wherein the plurality of thermal cutoff devices are disposed on the same circumference about an axis of the roller. 25. A thermal fixing device, comprising: a roller; a heater that heats the roller; a temperature sensor provided proximate the roller to sense a temperature of the roller; and a thermal cutoff device provided proximate the roller to interrupt power supply to the heater, wherein the heater has a temperature distribution that is symmetrical in an axial direction of the roller with respect to a temperature distribution center, and at least one of the temperature sensor and the thermal cutoff device is disposed facing a surface of the roller in alignment with one of symmetrical positions spaced by a predetermined distance, in the axial direction of the roller from the temperature distribution center. 26. The thermal fixing device according to claim 25, wherein the predetermined distance is a distance, in the axial direction of the roller, between the temperature distribution centers and an intersection between temperature distribution curves obtained when heating by the heater is started and when heating by the heater is stabilized.
연구과제 타임라인
LOADING...
LOADING...
LOADING...
LOADING...
LOADING...
이 특허에 인용된 특허 (9)
Solomon Gary A. (Hillsboro OR) MacWilliams Peter D. (Aloha OR) Hayek George R. (Cameron Park CA) Wade Nicholas D. (Cameron Park CA) Asghar Abid (Sacramento CA), Arbitration signaling mechanism to prevent deadlock guarantee access latency, and guarantee acquisition latency for an e.
James B. Keller ; Dale Gulick ; Larry Hewitt ; Geoffrey Strongin, Circuit and method for selectively stalling interrupt requests initiated by devices coupled to a multiprocessor system.
Chin Kenneth T. ; Johnson Jerome J. ; Jones Phillip M. ; Lester Robert A. ; Piccirillo Gary J. ; Stevens Jeffrey C. ; Coffee C. Kevin ; Collins Michael J. ; Larson John, Computer system employing memory controller and bridge interface permitting concurrent operation.
Normoyle Kevin B. ; Csoppenszky Michael A. ; Boddu Jaybharat ; Su Jui-Cheng ; Han Alex S. ; Cherabuddi Rajasekhar ; Tzeng Tzungren, Low-latency, high-throughput, integrated cache coherent I/O system for a single-chip processor.
Kalkunte Ramsesh (Acton MA) Rege Satish (Groton MA) Edgar Ronald (Raymond NH), Method and apparatus for arbitrating conflicts by monitoring number of access requests per unit of time in multiport mem.
Daly, Jr., George W.; Fields, Jr., James S.; Guthrie, Guy L.; Starke, William J.; Stuecheli, Jeffrey A., Data processing system and method that permit pipelining of I/O write operations and multiple operation scopes.
Golander, Amit; Heymann, Omer; Levison, Nadav; Robinson, Eric F., Livelock prevention mechanism in a ring shaped interconnect utilizing round robin sampling.
Genduso, Thomas Basilio; Harper, Richard Edwin, Method and system for improving input/output performance by proactively flushing and locking an entire page out of caches of a multiprocessor system.
Riocreux, Peter Andrew; Mathewson, Bruce James; Laycock, Christopher William; Grisenthwaite, Richard Roy, Synchronising activities of various components in a distributed system.
Dickson,Christopher; Caliga,David; O'Connor,James; Poznanovic,Daniel, System and method for explicit communication of messages between processes running on different nodes in a clustered multiprocessor system.
Vartti,Kelvin S.; Williams,James A.; Englin,Donald C., System and method for maintaining memory coherency within a multi-processor data processing system.
※ AI-Helper는 부적절한 답변을 할 수 있습니다.