What if the directory shows that line is not clean and written by other processor P? should we make that processor to flush the line or we just invalidate it because no one will use this value?
harlenVII
I think it will flush first because write operation indicates potential read.
like (a = a + 1)
thunder
I think it depends on the invalidation protocol. If the cache is applying MESI invalidation protocol, according to the specification on this slide, when a M state cache line receives a BusRdX, it will first flush the line and then set the state to I.
What if the directory shows that line is not clean and written by other processor P? should we make that processor to flush the line or we just invalidate it because no one will use this value?
I think it will flush first because write operation indicates potential read.
like (a = a + 1)
I think it depends on the invalidation protocol. If the cache is applying MESI invalidation protocol, according to the specification on this slide, when a M state cache line receives a BusRdX, it will first flush the line and then set the state to I.