Patent ID: 7950013

Claim:
A storage system having a single processor that operates in a multitasking operation system environment, the storage system comprising: an operation time manager that, when a processing time proportion for an interrupt processing, for which both an internal request and an external request are made to the storage system, in a first processing monitoring time period is not within a first threshold range, changes the first threshold range to a second threshold range which is lower than the first threshold range to restrict an allowable interrupt processing time proportion in a second processing monitoring time period which is subsequent to the first processing monitoring time period; wherein the operation time manager, when the processing time proportion for the interrupt processing in the second processing monitoring time period is within the first threshold range, changes the second threshold range to the first threshold range in a third processing monitoring time period which is subsequent to the second processing time period; and wherein when a processing time proportion for a task processing, for which both an internal request and an external request are made to the storage system, in the first processing monitoring time period is not within a third threshold range, the operation time manager changes the third threshold range to a fourth threshold range which is lower than the third threshold range to restrict an allowable task processing time proportion in the second processing monitoring time period; and when the task processing proportion in the second processing monitoring time period is within the third threshold range, the operation time manager changes the fourth threshold range to the third threshold range in the third processing monitoring time period.