Abstract: The present invention utilizes pageable pool memory to provide, via a data verifier component, data verification information for storage mediums. By allowing the utilization of pageable pool memory, overflow from the pageable pool memory is paged and stored in a virtual memory space on a storage medium. Recently accessed verification information is stored in non-pageable memory, permitting low latency access. One instance of the present invention synchronously verifies data when verification information is accessible in physical system memory while deferring processing of data verification when verification information is stored in paged memory. Another instance of the present invention allows access to paged verification information in order to permit synchronous verification of data.

Abstract: The present invention utilizes pageable pool memory to provide, via a data verifier component, data verification information for storage mediums. By allowing the utilization of pageable pool memory, overflow from the pageable pool memory is paged and stored in a virtual memory space on a storage medium. Recently accessed verification information is stored in non-pageable memory, permitting low latency access. One instance of the present invention synchronously verifies data when verification information is accessible in physical system memory while deferring processing of data verification when verification information is stored in paged memory. Another instance of the present invention allows access to paged verification information in order to permit synchronous verification of data.

Abstract: A method and system for verifying computer system drivers such as kernel mode drivers. A driver verifier sets up tests for specified drivers and monitors the driver's behavior for selected violations that cause system crashes. In one test, the driver verifier allocates a driver's memory pool allocations from a special pool bounded by inaccessible memory space to test for the driver's accessing memory outside of the allocation. The driver verifier also marks the space as inaccessible when it is deallocated, detecting a driver that accesses deallocated space. The driver verifier may also provide extreme memory pressure on a specific driver, or randomly fail requests for pool memory. The driver verifier also checks call parameters for violations, performs checks to ensure a driver cleans up timers when deallocating memory and cleans up memory and other resources when unloaded. An I/O verifier is also described for verifying drivers use of I/O request packets.

Abstract: A system and method for self-diagnosing a likely cause of a system crash is disclosed. A mechanism within an operating system checks for the existence of a stop code at startup of the machine. The existence of the stop code indicates that the system crashed during the previous session, and the type of system crash. The mechanism may read the stop code and implement a self-diagnostic procedure that corresponds to that stop code. In this manner, the mechanism may automate many of the tasks normally performed by humans, such as a system administrator, to self-diagnose the likely cause of the crash. If the crash occurs again, the mechanism, through the tracking procedures automatically implemented, may identify and report to a system administrator the likely cause of the crash, e.g. the particular faulty driver or configuration error.

Abstract: Access bit contained in a page table entry is utilized for reducing the number of translation buffer flushes that an operating system needs to issue. A translation buffer flush occurs only when a page table entry is to become invalid and the Access bit of the page table entry is set.

Abstract: A method and system for verifying computer system drivers such as kernel mode drivers. A driver verifier sets up tests for specified drivers and monitors the driver's behavior for selected violations that cause system crashes. In one test, the driver verifier allocates a driver's memory pool allocations from a special pool bounded by inaccessible memory space for testing the driver's accessing memory outside of the allocation. The driver verifier also marks the space as inaccessible when it is deallocated, detecting a driver that accesses deallocated space. The driver verifier may also provide extreme memory pressure on a specific driver, or randomly fail requests for pool memory. The driver verifier also checks call parameters for violations, performs checks to ensure a driver cleans up timers when deallocating memory and cleans up memory and other resources when unloaded. An I/O verifier is also described for verifying drivers use of I/O request packets.

Abstract: An efficient write-watch mechanism and process. A bitmap is associated with the virtual address descriptor (VAD) for a process, one bit for each virtual page address allocated to a process having write-watch enabled. As part of the write-watch mechanism, if a virtual address is trimmed to disk and that virtual address page is marked as modified, then the corresponding bit in the VAD is set for that virtual address page. In response to an API call (e.g., from a garbage collection mechanism) seeking to know which virtual addresses in a process have been modified since last checked, the memory manager walks the bitmap in the relevant VAD for the specified virtual address range for the requested process. If a bit is set, then the page corresponding to that bit is known to have been modified since last asked. If specified by the API, the bit is cleared in the VAD bitmap so that it will reflect the state since this time of asking.

Abstract: The present invention is directed to a method and system for minimizing memory access latency during realtime processing. The method includes a mechanism for marking information that will be accessed during realtime processing. The marked information may include code, data, heaps, stacks, as well as other information. The method includes support for locking down all of the marked information so that it is present in a computing machine's physical memory so that no page faults will be incurred during realtime processing. The method additionally enables realtime processing code to allocate and free memory in a non-blocking manner. It does so by enabling the creation of heaps for use during realtime processing, wherein each heap supports allocating and freeing memory in a non-blocking fashion. Each heap tracks freed memory blocks using individual non-blocking tracking lists for each memory block size supported by that heap.

Abstract: The present invention utilizes pageable pool memory to provide, via a data verifier component, data verification information for storage mediums. By allowing the utilization of pageable pool memory, overflow from the pageable pool memory is paged and stored in a virtual memory space on a storage medium. Recently accessed verification information is stored in non-pageable memory, permitting low latency access. One instance of the present invention synchronously verifies data when verification information is accessible in physical system memory while deferring processing of data verification when verification information is stored in paged memory. Another instance of the present invention allows access to paged verification information in order to permit synchronous verification of data.

Abstract: A system and method for self-diagnosing a likely cause of a system crash is disclosed. A mechanism within an operating system checks for the existence of a stop code at startup of the machine. The existence of the stop code indicates that the system crashed during the previous session, and the type of system crash. The mechanism may read the stop code and implement a self-diagnostic procedure that corresponds to that stop code. In this manner, the mechanism may automate many of the tasks normally performed by humans, such as a system administrator, to self-diagnose the likely cause of the crash. If the crash occurs again, the mechanism, through the tracking procedures automatically implemented, may identify and report to a system administrator the likely cause of the crash, e.g. the particular faulty driver or configuration error.

Abstract: An efficient write-watch mechanism and process. A bitmap is associated with the virtual address descriptor (VAD) for a process, one bit for each virtual page address allocated to a process having write-watch enabled. As part of the write-watch mechanism, if a virtual address is trimmed to disk and that virtual address page is marked as modified, then the corresponding bit in the VAD is set for that virtual address page. In response to an API call (e.g., from a garbage collection mechanism) seeking to know which virtual addresses in a process have been modified since last checked, the memory manager walks the bitmap in the relevant VAD for the specified virtual address range for the requested process. If a bit is set, then the page corresponding to that bit is known to have been modified since last asked. If specified by the API, the bit is cleared in the VAD bitmap so that it will reflect the state since this time of asking.

Abstract: An efficient write-watch mechanism and process. A bitmap is associated with the virtual address descriptor (VAD) for a process, one bit for each virtual page address allocated to a process having write-watch enabled. As part of the write-watch mechanism, if a virtual address is trimmed to disk and that virtual address page is marked as modified, then the corresponding bit in the VAD is set for that virtual address page. In response to an API call (e.g., from a garbage collection mechanism) seeking to know which virtual addresses in a processs have been modified since last checked, the memory manager walks the bitmap in the relevant VAD for the specified virtual address range for the requested process. If a bit is set, then the page corresponding to that bit is known to have been modified since last asked. If specified by the API, the bit is cleared in the VAD bitmap so that it will reflect the state since this time of asking.

Abstract: A system and method for self-diagnosing a likely cause of a system crash is disclosed. A mechanism within an operating system checks for the existence of a stop code at startup of the machine. The existence of the stop code indicates that the system crashed during the previous session, and the type of system crash. The mechanism may read the stop code and implement a self-diagnostic procedure that corresponds to that stop code. In this manner, the mechanism may automate many of the tasks normally performed by humans, such as a system administrator, to self-diagnose the likely cause of the crash. If the crash occurs again, the mechanism, through the tracking procedures automatically implemented, may identify and report to a system administrator the likely cause of the crash, e.g. the particular faulty driver or configuration error.

Abstract: The present invention includes a method of mirroring memory that reduces the down time for copying information from one physical memory subsystem to a redundant physical memory subsystem by separating the mirroring process into phases. The first phase copies information from the first physical memory subsystem to the redundant physical memory subsystem. During the first phase, applications are not restricted from accessing the first memory subsystem while the first phase of the memory mirroring operation copies the information. The second phase of the memory mirroring operation copies active information to the redundant physical memory subsystem. The active information includes information that was not copied during the first phase and information that changed during the first phase. During the second phase, applications are restricted from accessing the first physical memory subsystem.

Abstract: The present invention includes a method of mirroring memory that reduces the down time for copying information from one physical memory subsystem to a redundant physical memory subsystem by separating the mirroring process into phases. The first phase copies information from the first physical memory subsystem to the redundant physical memory subsystem. During the first phase, applications are not restricted from accessing the first memory subsystem while the first phase of the memory mirroring operation copies the information. The second phase of the memory mirroring operation copies active information to the redundant physical memory subsystem. The active information includes information that was not copied during the first phase and information that changed during the first phase. During the second phase, applications are restricted from accessing the first physical memory subsystem.

Abstract: A system and method for providing applications with the ability to access an increased amount of memory. An application maps a specified address range in its (small) virtual memory space to a corresponding number of pages allocated thereto in (relatively large) physical memory. When the application accesses an address in that range in virtual memory, e.g., via a thirty-two-bit address, the mapping information is used to access the corresponding page currently pointed to in the physical memory, allowing access to significantly greater amounts of memory. Fine granularity of access (e.g., one page) is provided, along with fast remapping, cross-process security and coherency across multiple processors in a multiprocessor system. To this end, a memory manager maintains information related to the mapping of virtual addresses to physical pages, in order to verify remap requests and invalidate existing mappings from a virtual address to a previously mapped physical page.