摘要:
Methods, systems, and physical computer-readable storage medium for processing a plurality of IO request jobs are provided. The method includes determining whether one or more request jobs are not meeting a QoS target, each job of the one or more request jobs having a corresponding priority, selecting a highest priority job from the one or more request jobs, if one or more request jobs are not meeting the QoS target, determining whether the highest priority job has a corresponding effective rate limit imposed thereon, if so, relaxing the corresponding effective rate limit, and if not, selecting one or more lower priority jobs from the one or more request jobs and tightening a corresponding effective limit on the one or more lower priority jobs from the one or more request jobs in accordance with a delay factor limit.
摘要:
For managing a storage server having improving overall system performance, a first input/output (I/O) request is received. A first priority level is dynamically assigned to the first I/O request, the first I/O request associated with a performance level for an application residing on a host in communication with the storage server. A second I/O request of a second priority level is throttled to allow at least a portion of a predetermined amount of resources previously designated for performing the second I/O request to be re-allocated to performing the first I/O request. The second priority level is different than the first priority level.
摘要:
A method of enabling state save and debug operations for co-routines for first failure data capture (FFDC) in an event-driven environment. A stack management utility allocates space for a context structure, which includes a state field, and a stack pointer in a buffer. A context management utility initializes a first context structure of a first co-routine and saves a state of the first context structure in response to an execution request for a second co-routine. The context management utility sets a second context structure as a current context. When execution of the current context is complete, the context management utility restores the first context structure of the first co-routine as the current context. If the state field is not set to a valid value, a state save function “state saves” all allocated co-routine stacks and context structures, restores the entire system to a previous valid state, and restarts operations.
摘要:
A technique for handling hardware errors in a computing system, such as a data storage facility, while avoiding a system crash. An interface is registered with an operating system of the computing system to process hardware errors. When a hardware error is detected, the interface checks an error register to identify the adapter that likely causes the error, and quarantines, e.g., blocks off, the offending adapter from the computing system. The interface then notifies the operating system that the error has been handled, thereby causing the operating system to bypass a system crash that would otherwise occur. The interface can be provided as a kernel extension of a device driver associated with the operating system.
摘要:
An adaptive hierarchical cache management system for improving effective cache hit ratios by eliminating unnecessary duplicate cache entries in two coupled cache memories. When a cached Storage Controller (SC) is coupled to a Cached Storage Drawer (CSD), the hierarchical coupling of the SC cache memory and CSD cache memory unnecessarily duplicates cache entries during normal operation. A Conditional Purge procedure purges duplicate lines from the CSD cache subject to a DASD activity threshold. A Prenotify Intent parameter allows the SC to request restaging of the purged cache entry preparatory to fast write or LRU demotion in the SC cache. The new procedures substantially and transparently improve the combined caching efficiency without significant new hardware or software overhead.
摘要:
A method of enabling state save and debug operations for co-routines for first failure data capture (FFDC) in an event-driven environment. A stack management utility allocates space for a context structure, which includes a state field, and a stack pointer in a buffer. A context management utility initializes a first context structure of a first co-routine and saves a state of the first context structure in response to an execution request for a second co-routine. The context management utility sets a second context structure as a current context. When execution of the current context is complete, the context management utility restores the first context structure of the first co-routine as the current context. If the state field is not set to a valid value, a state save function “state saves” all allocated co-routine stacks and context structures, restores the entire system to a previous valid state, and restarts operations.
摘要:
Mechanisms for controlling access to storage volumes on the secondary storage system is provided. A determination is made as to whether a first site computing device has sent a notification of a failure condition of a first site. In response to a determination that the notification of the failure condition of the first site has not been received, secondary workloads of a second site computing device are permitted to access storage volumes on the secondary storage system. In response to a determination that the notification of the failure condition of the first site has been received, a mode of operation of the second site is modified from a normal mode of operation to a failure mode of operation. In the failure mode of operation, the storage system controller of the second site blocks at least a portion of access requests from secondary workloads of the second site computing device.
摘要:
Mechanisms for controlling access to storage volumes on the secondary storage system is provided. A determination is made as to whether a first site computing device has sent a notification of a failure condition of a first site. In response to a determination that the notification of the failure condition of the first site has not been received, secondary workloads of a second site computing device are permitted to access storage volumes on the secondary storage system. In response to a determination that the notification of the failure condition of the first site has been received, a mode of operation of the second site is modified from a normal mode of operation to a failure mode of operation. In the failure mode of operation, the storage system controller of the second site blocks at least a portion of access requests from secondary workloads of the second site computing device.
摘要:
A method, apparatus and program storage device for providing an anchor pointer in an operating system context structure for improving the efficiency of accessing thread specific data is provided. A kernel thread context structure is maintained in memory. A thread accesses a pointer memory in the kernel thread context structure and sets a value within the pointer memory that addresses data specific to the thread.
摘要:
An instruction capable of preventing incorrect usage of ucontext functions in a multi-process environment is disclosed. During an execution of a setcontext instruction, a determination is made whether or not a contextID of a context structure associated with a next context indicates that it is an original context of a process. If the contextID of the next context structure is an original context of a process, another determination is made whether or not the contextID of the context structure associated with the next context is the same as the original contextID of the process. If the contextID of the context structure associated with the next context is not the same as the original contextID of the process, an error recovery routine is invoked.