Method of starting execution of threads simultaneously at a plurality of processors and device therefor

In a multi-processor system in which a plurality of threads to be simultaneously executed at a plurality of processors are stored as one thread set at a context area one-to-one corresponding to a thread set provided in a context save area on a main storage, a method of enabling a plurality of processors to start execution of threads simultaneously, comprising the steps:

• (a) of conducting exclusive arbitration during exception processing of each processor so as to temporarily allow only one processor to obtain kernel scheduler execution authority,
• (b) of a processor obtaining kernel scheduler execution authority to save a context of a thread being executed by its own processor in the context save area on the main storage, as well as issuing a context save request as an inter-processor interruption to a processor executing other thread in the thread set to which the thread in question belongs,
• (c) of a processor issuing a context save request to, after confirming the completion of context saving at all of the requested processors, issue a context reading request regarding a thread to be executed by other processor in a thread set to be executed next to a processor which is to execute the thread in question, as well as reading a context of a thread to be executed by its own processor in the thread set to be executed next from the context save area on the main storage to return the context,
• (d) of a processor receiving said context reading request to read a context of the thread to return the context, and
• (e) upon completion of context return at all the processors executing threads in said thread set, of all the relevant processors to simultaneously start execution of threads.

In a multi-processor system in which a plurality of threads to be simultaneously executed at a plurality of processors are stored as one thread set at a context area one-to-one corresponding to a thread set provided in a context save area on a main storage, a device which enables a plurality of processors to start execution of threads simultaneously, comprising:

• means for conducting exclusive arbitration during exception processing of each processor so as to temporarily allow only one processor to obtain kernel scheduler execution authority,
• means for a processor obtaining kernel scheduler execution authority to save a context of a thread being executed by its own processor in the context save area on the main storage, as well as issuing a context save request as an inter-processor interruption to a processor executing other thread in the thread set to which the thread in question belongs,
• means for a processor issuing a context save request to, after confirming the completion of context saving at all of the requested processors, issue a context reading request regarding a thread to be executed by other processor in a thread set to be executed next to a processor which is to execute the thread in question,
• means for reading a context of a thread to be executed by its own processor in a thread set to be executed next from the context save area on the main storage to return the context,
• means for a processor receiving said context reading request to read a context of a thread and return the context, and
• mean for, upon completion of context return at all the processors executing threads in said thread set, enabling all the relevant processors to simultaneously start execution of threads.

In a multi-processor system in which a plurality of threads to be simultaneously executed at a plurality of processors are stored as one thread set at a context area one-to-one corresponding to a thread set provided in a context save area on a main storage, a computer readable memory for storing a program which enables a plurality of processors to start execution of threads simultaneously,

• said program comprising the steps:
• (a) of conducting exclusive arbitration during exception processing of each processor so as to temporarily allow only one processor to obtain kernel scheduler execution authority,
• (b) of a processor obtaining kernel scheduler execution authority to save a context of a thread being executed by its own processor in the context save area on the main storage, as well as issuing a context save request as an inter-processor interruption to a processor executing other thread in the thread set to which the thread in question belongs,
• (c) of a processor issuing a context save request to, after confirming the completion of context saving at all of the requested processors, issue a context reading request regarding a thread to be executed by other processor in a thread set to be executed next to a processor which is to execute the thread in question, as well as reading a context of a thread to be executed by its own processor in the thread set to be executed next from the context save area on the main storage to return the context,
• (d) of a processor receiving said context reading request to read a context of the thread to return the context, and
• (e) upon completion of context return at all the processors executing threads in said thread set, of all the relevant processors to simultaneously start execution of threads.