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公开(公告)号：GB2348303A
公开(公告)日：2000-09-27
申请号：GB9906501
申请日：1999-03-23
Applicant: IBM
Abstract: A task managing method in which multiple tasks are assigned to a processor with varying frequency and differing processing demands. The method involves adjusting the method of dealing with tasks according to the load requirements placed upon the processor. A polling method is used when there is a high demand or frequent task arrival and an interrupt method is used when there is a low demand or infrequent task arrival. An interrupt 320 is generated in response to receipt of a first task and the task is scheduled on a task queue for later processing. The interrupt is then disabled 330. When the scheduled task 340 reaches the head of the queue, the task is executed 350 along with all other tasks that have been added to the queue since the first task was scheduled 360,370. When all the tasks have been processed, a further task is speculatively scheduled 380 to check for and execute any tasks subsequently placed on the task queue. When this speculatively scheduled task reaches the end of the queue it is executed 390, and if any new tasks are found yet another task is speculatively scheduled 380 to check 400 for and execute 410,420 any tasks subsequently placed on the task queue. If no new tasks are found on the queue the interrupt is re-enabled 310. A particular use of the invention is detailed for a storage controller. The advantage is that switching between interrupt-driven and polling-driven methods in such a manner allows efficient utilisation of processor resources according to the loading that the tasks make on the processor.
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Patent Agency Ranking
公开(公告)号：DE602007002827D1
公开(公告)日：2009-11-26
申请号：DE602007002827
申请日：2007-08-02
Applicant: IBM
Inventor： BURR DALE , BUTTERWORTH HENRY ESMOND
IPC: G06F11/20
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公开(公告)号：GB2366014B
公开(公告)日：2004-10-13
申请号：GB0020395
申请日：2000-08-19
Applicant: IBM
Inventor： BUTTERWORTH HENRY ESMOND
Abstract: A method for performing free space collection in an information storage system and an information storage system ( 104 ) are described. The information storage system ( 104 ) is a log structured system having storage units ( 106 ) in which information segments ( 202, 204 ) are located. Free space collection is carried out in the storage units by using a fitness value to evaluate segments ( 204 ). The fitness value is determined as the product of the amount of free space in a segment ( 204 ) and the expected time the free space will last ( 310 ). Segments ( 204 ) are chosen for free space collection if they have the maximum fitness value ( 312 ). The segments ( 204 ) are sorted into groups by the amount of used data in each segment ( 204 ) and the fitness value is determined for one segment from each group.
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公开(公告)号：AU2003251059A8
公开(公告)日：2004-06-23
申请号：AU2003251059
申请日：2003-08-13
Applicant: IBM
Inventor： BUTTERWORTH HENRY ESMOND , FUENTE CARLOS FRANCISCO
Abstract: A method, storage system, and machine-readable medium for resynchronizing data stored among a first storage element and a second storage element of a remote copy pair of storage elements is disclosed. According to one embodiment, a method is provided which includes detecting a reestablishment of a remote copy relationship between the first and second storage elements and performing a resynchronization operation in response to this detection. Performing the resynchronization operation comprises transmitting data of a second change record associated with the second storage element to the first storage element, combining the second change record with a first change record associated with the first storage element, identifying a data segment of the second storage element utilizing the combined change record, and overwriting data of the first storage element with data of the identified data segment.
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公开(公告)号：GB2365545B
公开(公告)日：2004-06-02
申请号：GB9930282
申请日：1999-12-23
Applicant: IBM
Abstract: A data processing system comprises a master processor ( 10 ), a slave processor ( 30 ), a memory ( 50 ), and a bus subsystem ( 20 ) interconnecting the master processor ( 10 ), the slave processor ( 30 ), and the memory ( 50 ). The master processor ( 10 ) is configured to generate, in response to a memory access instruction, a read request comprising a read command for execution by the slave processor ( 30 ) to read data stored in a location in the memory ( 50 ) specified by the memory access instruction, and to write the read request to the slave processor ( 30 ) via the bus subsystem ( 20 ). The slave processor ( 30 ) is configured to execute the read command received in the read request from the master processor ( 10 ) to obtain the data stored at the specified location in the memory ( 50 ) and to write the data thus obtained to the master processor ( 10 ) via the bus subsystem ( 20 ).
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公开(公告)号：GB2369206A
公开(公告)日：2002-05-22
申请号：GB0028214
申请日：2000-11-18
Applicant: IBM
Inventor： BUTTERWORTH HENRY ESMOND , NICHOLSON ROBERT BRUCE
Abstract: A program, system and method for rebuilding meta-data stored in a data storage system 104 having storage devices 106 in which segments of data are located; for example, a storage system in the form of a log structured array. Data is written in segments to the storage devices 106 from a plurality of flows 122 of data and each segment of data contains meta-data relating to that segment. The meta-data stored in the storage system 104 can be rebuilt in the event of a failure by scanning the meta-data in each segment. A first scan of the meta-data in each segment in the storage devices 106 identifies the last segment written from each flow 122 and these segments are excluded from the rebuilding process as they may contain incomplete or inconsistent information. A second scan of the meta-data in each segment in the storage devices 106 identifies any segments which do not contain any live data tracks and these segments are also excluded from the rebuilding process. The meta-data in the storage system 104 can then be rebuilt using the meta-data in the segments, excluding those segments identified.
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