Efficient detection and respone to spin waits in multi-processor virtual machines

A system for attenuating spin waiting of virtual processors in a virtual machine environment, comprising:

• a processor;
• and
• a memory communicatively coupled to the processor and storing instructions that upon execution by the processor cause the system to:
• examine a hint source for hints to determine if a virtual processor is accessing a synchronizing section that acquires a lock on an underlying physical resource that causes any other virtual processors to spin wait until the virtual processor releases the lock;
• provide a time slice extension to the virtual processor to increase the time allotted in its assigned time slice if the virtual processor is accessing the synchronizing section;
• and
• end the time slice extension prematurely.

A computer readable medium comprising machine readable instructions that, upon execution, cause the machine to:

• examine a hint source for hints to determine if a virtual processor is accessing a synchronizing section that acquires a lock on an underlying physical resource that causes any other virtual processors to spin wait until the virtual processor releases the lock;
• provide a time slice extension to the virtual processor to increase the time allotted in its assigned time slice if the virtual processor is accessing the synchronizing section;
• and
• end the time slice extension prematurely;
• wherein the instructions for ending the time slice extension prematurely include at least one of:
• (a) instructions for setting an intercept with said hint source and receiving the intercept from the hint source;
• and (b) instructions for receiving a signal from an enlightened guest operating system indicating that the synchronizing section has been cleared.