-
公开(公告)号：DE68923863T2
公开(公告)日：1996-03-28
申请号：DE68923863
申请日：1989-12-11
Applicant: IBM
Inventor： CHANG ALBERT , LEROM GEORGE ALBERT , NICHOLSON JAMES OTTO , O'QUIN III JOHN CLAUDE , O'QUIN II JOHN THOMAS
Abstract: A cache for use with input/output devices attached to an input/output bus. Requests for access to system memory by an input/output device pass through the cache. Access authority is checked to determine whether an input/output device is authorised to access that particular page. If it is not, access is denied. Each input/output device has access to a portion of the cache, so that activity by one device will not interfere with activity by another.
-
公开(公告)号：DE3750824T2
公开(公告)日：1995-05-24
申请号：DE3750824
申请日：1987-01-08
Applicant: IBM
-
公开(公告)号：DE3382307D1
公开(公告)日：1991-07-11
申请号：DE3382307
申请日：1983-12-22
Applicant: IBM
Inventor： CHANG ALBERT , COCKE JOHN , MERGEN MARK , RADIN GEORGE
Abstract: A virtual memory address translation mechanism is provided for converting virtual memory addresses provided by a CPU into real memory addresses within page frames in a large hierachial memories wherein the real memory space is substantially smaller than the scope of the virtual memory. The conversion or translation mechanism includes a combined table in the memory which includes a first list covering the respective virtual address of each memory address (Inverted Page or IPT) and a second list connecting each of a plurality of hashed addresses with a predetermined initial virtual address of a linked group of virtual addresses, each of which when hashed produces the connected hashed address (Hashed Addressed Table, HAT). The system also has means for hashing a selected virtual address to produce a hashed address. Also included in apparatus for sequentially searching through the linked group of virtual addresses in the combined table until a selected virtual address is located as well as apparatus responsive to the location of a particular selected virtual address for accessing from the first list, the real memory address of the located virtual address.
-
公开(公告)号：DE68923863D1
公开(公告)日：1995-09-21
申请号：DE68923863
申请日：1989-12-11
Applicant: IBM
Inventor： CHANG ALBERT , LEROM GEORGE ALBERT , NICHOLSON JAMES OTTO , O'QUIN III JOHN CLAUDE , O'QUIN II JOHN THOMAS
Abstract: A cache for use with input/output devices attached to an input/output bus. Requests for access to system memory by an input/output device pass through the cache. Access authority is checked to determine whether an input/output device is authorised to access that particular page. If it is not, access is denied. Each input/output device has access to a portion of the cache, so that activity by one device will not interfere with activity by another.
-
公开(公告)号：DE3851038T2
公开(公告)日：1995-03-09
申请号：DE3851038
申请日：1988-10-20
Applicant: IBM
Inventor： CHANG ALBERT , COCKE JOHN , MERGEN MARK FREDERICK , OEHLER RICHARD RAPHAEL
Abstract: A method of and a controller for accessing a protected memory which is logically divided into major partitions - pages - which are in turn sub-divided into minor partitions - blocks - by concurrently executing transactions, using virtual block addressing and address translation at the memory controller via an access table, wherein there are provided table entries containing priviledged access control fields relating to the pages and lock fields relating to the individual blocks, by receiving an address of a data block to be accessed by an identifiable transaction; deriving from the address an access table entry corresponding to the data block and testing the data in the page access control field and the lock field governing access to the block; and providing the requested access if permitted by the access control data and the lock data for the type of access concerned, and also providing recorded access, if not permitted but not specifically denied by the lock data, using at least part of the lock field to record such latter type of access.
-
Patent Agency Ranking
公开(公告)号：BR8806268A
公开(公告)日：1989-08-15
申请号：BR8806268
申请日：1988-11-29
Applicant: IBM
-
公开(公告)号：DE3750824D1
公开(公告)日：1995-01-19
申请号：DE3750824
申请日：1987-01-08
Applicant: IBM
-
公开(公告)号：BR8800246A
公开(公告)日：1988-08-30
申请号：BR8800246
申请日：1988-01-25
Applicant: IBM
Inventor： CHANG ALBERT , NEUMAN GROVER HERBERT , SHAHEEN-GOUDA AMAL A , SMITH TODD ALLEN
Abstract: In a distributed environment several data processing systems are interconnected across a network system (3). A distributed services program installed on the systems in the network allows the processors to access data files (5) distributed across the various nodes (A,B) of the network without regard to the location of the data file in the network. The processing system accessing the file, referred to as the client processing system, utilizes a client cache (12B) within its operating system (11B) to store the data file. Utilizing the client cache minimizes the number of reads and writes that must go over the network (3) to the server processing system where the file physically resides. The system and method of this invention prevents a process in the client processing system from accessing data in the client cache that has been modified at another node (A) in the network. The blocks of data in the client cache (12B) are tested for validity in the client processing system by using modification times as measured by the server processing system. If the cache data blocks are determined to be valid, the data is accessed from the client cache. If the cache data blocks are determined to be invalid, the data blocks are discarded, and the file is accessed from the server processing system.
-
公开(公告)号：DE3889739T2
公开(公告)日：1994-12-01
申请号：DE3889739
申请日：1988-01-26
Applicant: IBM
Inventor： CHANG ALBERT , SHAHEEN-GOUDA AMAL AHMED , NEUMAN GROVER HERBERT , SMITH TODD ALLEN
Abstract: In a distributed environment several data processing systems are interconnected across a network system (3). A distributed services program installed on the systems in the network allows the processors to access data files (5) distributed across the various nodes (A,B) of the network without regard to the location of the data file in the network. The processing system accessing the file, referred to as the client processing system, utilizes a client cache (12B) within its operating system (11B) to store the data file. Utilizing the client cache minimizes the number of reads and writes that must go over the network (3) to the server processing system where the file physically resides. The system and method of this invention prevents a process in the client processing system from accessing data in the client cache that has been modified at another node (A) in the network. The blocks of data in the client cache (12B) are tested for validity in the client processing system by using modification times as measured by the server processing system. If the cache data blocks are determined to be valid, the data is accessed from the client cache. If the cache data blocks are determined to be invalid, the data blocks are discarded, and the file is accessed from the server processing system.
-
公开(公告)号：DE3851038D1
公开(公告)日：1994-09-15
申请号：DE3851038
申请日：1988-10-20
Applicant: IBM
Inventor： CHANG ALBERT , COCKE JOHN , MERGEN MARK FREDERICK , OEHLER RICHARD RAPHAEL
Abstract: A method of and a controller for accessing a protected memory which is logically divided into major partitions - pages - which are in turn sub-divided into minor partitions - blocks - by concurrently executing transactions, using virtual block addressing and address translation at the memory controller via an access table, wherein there are provided table entries containing priviledged access control fields relating to the pages and lock fields relating to the individual blocks, by receiving an address of a data block to be accessed by an identifiable transaction; deriving from the address an access table entry corresponding to the data block and testing the data in the page access control field and the lock field governing access to the block; and providing the requested access if permitted by the access control data and the lock data for the type of access concerned, and also providing recorded access, if not permitted but not specifically denied by the lock data, using at least part of the lock field to record such latter type of access.
-
-
-
-
-
-
-
-
-
Search Results
17
records
(took 0.017 seconds)
