Method for managing virtual memory to separate active and stable memory
blocks
    1.
    发明授权
    Method for managing virtual memory to separate active and stable memory blocks 失效
    用于管理虚拟内存以分离主动和稳定的内存块的方法

    公开(公告)号:US4660130A

    公开(公告)日:1987-04-21

    申请号:US634334

    申请日:1984-07-24

    CPC分类号: G06F12/122 G06F12/0253

    摘要: A method for compacting blocks of memory in a demand paged virtual address space which includes a plurality of virtual address pages includes identifying active and stable blocks to be compacted by defining a pointer to indicate a page of the virtual memory space, and advancing the pointer to continually indicate the page of the beginning of the available virtual memory space. As new blocks are allocated, they are located in the virtual address space beginning at the next available location of the advancing pointer. As blocks are referenced by the user, they are moved to the current location of the advancing pointer, so that, stable blocks may be collected together on stable pages and active blocks are collected together on active pages. A disk memory is provided, and periodically the pages containing collected stable blocks are "paged-out" to it. The method improves the overall throughput of data in the memory by reducing the time waiting for disk, the time in which the CPU is delayed during frequent garbage collections, and the allocation response time. Also, the method insures efficient use of the backing store by insuring that sparsely allocated pages are not written out to disk.

    摘要翻译: 一种用于在包含多个虚拟地址页的需求分页虚拟地址空间中压缩存储器块的方法包括:通过定义指示虚拟存储器空间的页面的指针来识别待压缩的活动和稳定块,并且将指针推向 持续指示可用虚拟内存空间开头的页面。 当分配新的块时,它们位于从前进指针的下一个可用位置开始的虚拟地址空间中。 当用户引用块时,它们被移动到前进指针的当前位置,使得可以在稳定页面上一起收集稳定块,并且活动块在活动页面上一起收集。 提供磁盘存储器,并且周期性地将包含收集的稳定块的页面“分页”。 该方法通过减少等待磁盘的时间,在频繁的垃圾收集期间CPU被延迟的时间以及分配响应时间来提高存储器中数据的总体吞吐量。 此外,该方法通过确保稀疏分配的页面不被写出到磁盘来确保有效地使用后台存储。

    Incremental, multi-area, generational, copying garbage collector for use
in a virtual address space
    2.
    发明授权
    Incremental, multi-area, generational, copying garbage collector for use in a virtual address space 失效
    用于虚拟地址空间的增量,多区域,世代,复制垃圾收集器

    公开(公告)号:US4797810A

    公开(公告)日:1989-01-10

    申请号:US878551

    申请日:1986-06-26

    CPC分类号: G06F12/0276 Y10S707/99957

    摘要: An incremental garbage collector for use in conjunction with a virtual memory, operates on selected generations of an area upon objects which are contained in a semispace, oldspace or newspace, and during the garbage collection process, all accessible objects are copied from the oldspace to the newspace. The garbage collection process occurs in four phases. In the "flip" phase oldspace and newspace of each generation are exchanged. In the "trace" phase, the pointers which are part of a root set of the generation being collected are traced and all oldspace objects referenced by the pointers are copied to newspace, and the pointers in the root set are updated. All copied objects are then "scavenged" to update any pointers in the cells of the copied objects, and to copy to newspace all oldspace objects referenced by those pointers. Finally a "cleaning oldspace" phase is performed as a low-priority background process to purge the entries for the virtual pages on which "obsolete" pointers reside.

    摘要翻译: 与虚拟内存一起使用的增量垃圾收集器,对包含在半空间,旧空间或新空间中的对象的区域的选定世代进行操作,并且在垃圾收集过程中,所有可访问对象都从旧空间复制到 新空间 垃圾收集过程分四个阶段进行。 在“翻转”阶段,每一代的旧空间和新空间被交换。 在“跟踪”阶段中,跟踪所收集生成的根组的一部分的指针,并将指针引用的所有旧空间对象复制到新空间,并更新根集中的指针。 所有复制的对象然后被“清理”以更新复制对象的单元格中的任何指针,并将这些指针引用的所有旧空间对象复制到新空间。 最后,执行“清理旧空间”阶段作为低优先级后台进程,以清除“过时”指针所在的虚拟页面的条目。

    Computer memory system with parallel garbage collection independent from
an associated user processor
    3.
    发明授权
    Computer memory system with parallel garbage collection independent from an associated user processor 失效
    具有独立于相关用户处理器的并行垃圾收集的计算机存储器系统

    公开(公告)号:US4775932A

    公开(公告)日:1988-10-04

    申请号:US636187

    申请日:1984-07-31

    IPC分类号: G06F12/00 G06F12/02

    摘要: A memory system for association with a user processor for operation independently from the user processor includes a physical memory and an interface unit for enabling the associated user processor to access the physical memory. The physical memory is represented in a virtual address space which is garbage collected in parallel with the operation of the user processor. The garbage collection process includes reference count deallocation and a garbage collection algorithm for deallocating cyclic structures not deallocated by the reference count process. The reference count process includes providing for a reference count indicating the number of pointer references to a memory block in the virtual address space. When the reference count becomes zero, and no other references to a memory block exist, the block may be freed. In the garbage collection algorithm, the virtual memory space is traced in areas, called OLDSPACE, and compactly copied into a new area, called NEWSPACE. The OLDSPACE and NEWSPACE are further scavenged to insure that all referenced blocks of memory are copied, and the remaining OLDSPACE is cleaned. The garbage collection process is performed in parallel with the operation of the user processor.

    摘要翻译: 用于与用户处理器相关联以用于独立于用户处理器的操作的存储器系统包括物理存储器和用于使相关联的用户处理器能够访问物理存储器的接口单元。 物理存储器在与用户处理器的操作并行收集的虚拟地址空间中表示。 垃圾收集过程包括引用计数解除分配和垃圾收集算法,用于释放通过引用计数过程而不被释放的循环结构。 参考计数过程包括提供指示虚拟地址空间中的指针引用到存储器块的引用计数。 当引用计数为零时,并且不存在对存储器块的其他引用,则该块可以被释放。 在垃圾收集算法中,虚拟内存空间被跟踪在被称为OLDSPACE的区域中,并被紧密复制到一个称为NEWSPACE的新区域。 OLDSPACE和NEWSPACE进一步清理,以确保所有引用的内存块都被复制,剩下的OLDSPACE被清理。 垃圾收集过程与用户处理器的操作并行执行。

    Computer memory system having persistent objects
    4.
    发明授权
    Computer memory system having persistent objects 失效
    具有持久性对象的计算机存储系统

    公开(公告)号:US4853842A

    公开(公告)日:1989-08-01

    申请号:US159467

    申请日:1988-02-19

    IPC分类号: G06F9/44 G06F12/02

    摘要: A uniform memory system for use with symbolic computers has a very large virtual address space. No separate files, not directly addressable in the address space of the virtual memory, exist. A special object, the peristent root, defines memory objects which are relatively permanent, such objects being traceable by pointers from the persistent root. A tombstone mechanism is used to prevent objects from referencing deleted objects.

    摘要翻译: 与符号计算机一起使用的统一存储系统具有非常大的虚拟地址空间。 不存在在虚拟内存的地址空间中不能直接寻址的单独文件。 一个特殊的对象,即根本的根,定义了相对永久的内存对象,这些对象可以通过持久根的指针进行追踪。 使用墓碑机制来防止对象引用已删除的对象。

    Cache hierarchy design for use in a memory management unit
    5.
    发明授权
    Cache hierarchy design for use in a memory management unit 失效
    缓存层次结构设计用于内存管理单元

    公开(公告)号:US4985829A

    公开(公告)日:1991-01-15

    申请号:US068788

    申请日:1987-06-26

    IPC分类号: G06F12/08 G06F12/10

    CPC分类号: G06F12/1063 G06F12/0864

    摘要: A cache hierarchy to be managed by a memory management unit (MMU) combines the advantages of logical and virtual address caches by providing a cache hierarchy having a logical address cache backed up by a virtual address cache to achieve the performance advantage of a large logical address cache, and the flexibility and efficient use of cache capacity of a large virtual address cache. A physically small logical address cache is combined with a large virtual address cache. The provision of a logical address cache enables reference count management to be done completely by the controller of the virtual address cache and the memory management processor in the MMU. Since the controller of the logical address cache is not involved in the overhead associated with reference counting, higher performance is accomplished as the CPU-MMU interface is released as soon as the access to the logical address cache is completed.

    摘要翻译: 由存储器管理单元(MMU)管理的高速缓存层次结构通过提供具有由虚拟地址缓存备份的逻辑地址缓存的高速缓存层级来组合逻辑和虚拟地址高速缓存的优点,以实现大逻辑地址的性能优势 缓存,以及灵活性和高效利用高速缓存的大容量虚拟地址缓存。 物理上小的逻辑地址缓存与大型虚拟地址缓存组合。 提供逻辑地址缓存使得引导计数管理能够由MMU中的虚拟地址缓存和存储器管理处理器的控制器完成。 由于逻辑地址缓存的控制器不涉及与引用计数相关联的开销,所以当完成对逻辑地址缓存的访问时,CPU-MMU接口被释放,就会实现更高的性能。

    Universal testing circuit and method
    7.
    发明授权
    Universal testing circuit and method 失效
    通用测试电路及方法

    公开(公告)号:US4594711A

    公开(公告)日:1986-06-10

    申请号:US551667

    申请日:1983-11-10

    申请人: Satish M. Thatte

    发明人: Satish M. Thatte

    IPC分类号: G01R31/3185 G01R31/28

    CPC分类号: G01R31/318547

    摘要: A test circuit, called a universal testing block (UTB) for on-chip testing of a VLSI subsystem such as a ROM or an ALU has several modes, including test generator and test evaluator, formed on the VLSI chip. The test generator circuit includes means for applying a predetermined test pattern to an input channel of the subsystem and may be a generator for generating pseudorandom test patterns for application to the subsystem. Alternatively, the test generator may be a counter which can be selectively activated to generate a binary up-count. The UTB also has a shift register mode having a serial input and output to enable serial data to be shifted into and out of the subsystem in parallel fashion. The test evaluator circuit receives output signals from the subsystem, and includes a parallel signature analyzer to generate a signature of the subsystem after the application of the test patterns by the input circuit to indicate whether the subsystem is fault-free. Also, means are provided for evaluating the signature and for generating a signal in accordance with the evaluation indicative of whether the subsystem is fault-free.

    摘要翻译: 称为通用测试块(UTB)的测试电路,用于VLSI子系统(例如ROM或ALU)的片上测试,具有在VLSI芯片上形成的多种模式,包括测试发生器和测试评估器。 测试发生器电路包括用于将预定测试模式应用于子系统的输入通道的装置,并且可以是用于生成用于子系统的伪随机测试模式的发生器。 或者,测试发生器可以是可以选择性地激活以产生二进制递增计数的计数器。 UTB还具有具有串行输入和输出的移位寄存器模式,以使得串行数据能够以并行方式移入和移出子系统。 测试评估器电路从子系统接收输出信号,并且包括并行签名分析器,用于在通过输入电路应用测试模式之后生成子系统的签名,以指示子系统是否无故障。 此外,提供了用于评估签名并根据指示子系统是否无故障的评估来生成信号的装置。

    Virtual memory recovery system using persistent roots for selective
garbage collection and sibling page timestamping for defining
checkpoint state
    9.
    发明授权
    Virtual memory recovery system using persistent roots for selective garbage collection and sibling page timestamping for defining checkpoint state 失效
    虚拟内存恢复系统使用持久根用于选择性垃圾收集和同级页面时间戳来定义检查点状态

    公开(公告)号:US4814971A

    公开(公告)日:1989-03-21

    申请号:US774828

    申请日:1985-09-11

    申请人: Satish M. Thatte

    发明人: Satish M. Thatte

    CPC分类号: G06F9/4435 G06F11/1438

    摘要: Periodic checkpoints are taken of the state of a computer system and its virtual memory. If a system crash occurs, the machine state can be rolled back to the checkpoint state and normal operation restarted. Pages of virtual memory are timestamped to indicate whether they are included in the checkpoint state. Modifications made after the checkpoint time are discarded when the system state is rolled back to the saved checkpoint state. Some recordkeeping is maintained outside of the virtual memory address space in order to assist with the recovery process.

    摘要翻译: 对计算机系统及其虚拟内存的状态进行定期检查。 如果发生系统崩溃,则可以将机器状态回滚到检查点状态,并重新启动正常操作。 虚拟内存的页面是时间戳的,以指示它们是否包含在检查点状态中。 当系统状态回滚到保存的检查点状态时,在检查点时间之后进行的修改将被丢弃。 某些记录保存在虚拟内存地址空间之外,以帮助恢复过程。

    Recoverable virtual memory having persistant objects
    10.
    发明授权
    Recoverable virtual memory having persistant objects 失效
    具有持久对象的可恢复虚拟内存

    公开(公告)号:US5008786A

    公开(公告)日:1991-04-16

    申请号:US932813

    申请日:1986-11-19

    申请人: Satish M. Thatte

    发明人: Satish M. Thatte

    IPC分类号: G06F9/44 G06F11/14

    CPC分类号: G06F9/4435 G06F11/1438

    摘要: A recoverable virtual memory for a computer system takes periodic checkpoints which capture the state of the virtual memory. If a system failure occurs, the system can be rolled back to the checkpointed state and restarted. A mechanism for tracking which virtual pages are contained in the checkpointed state discards pages which have been modified since the checkpointed state was saved. Only versions of pages which are saved in the checkpointed state are used in the restore process.

    摘要翻译: 用于计算机系统的可恢复虚拟存储器采用捕获虚拟存储器状态的定期检查点。 如果发生系统故障,系统可以回滚到检查点状态并重新启动。 用于跟踪在检查点状态中包含哪些虚拟页面的机制丢弃自保存点检状态以来已被修改的页面。 在恢复过程中仅使用保存在检查点状态的页面版本。