Volume 3: General-Purpose and System Instructions - Stanford ...

AMD64 Technology 24594 Rev. 3.10 February 2005WBINVDWriteback and Invalidate CachesThe WBINVD instruction writes all modified cache lines in the internal caches back tomain memory and invalidates (flushes) internal caches. It then causes external cachesto write back modified data to main memory; the external caches are subsequentlyinvalidated. After invalidating internal caches, the processor proceeds immediatelywith the execution of the next instruction without waiting for external hardware toinvalidate its caches.The INVD instruction can be used when cache coherence with memory is notimportant.This instruction does not invalidate TLB caches.This is a privileged instruction. The current privilege level of a procedure invalidatingthe processor’s internal caches must be zero.WBINVD is a serializing instruction.Mnemonic Opcode DescriptionWBINVD 0F 09 Write modified cache lines to main memory, invalidate internalcaches, and trigger external cache flushes.Related InstructionsCLFLUSH, INVDrFLAGS AffectedNoneExceptionsExceptionGeneral protection,#GPRealVirtual8086 Protected Cause of ExceptionX X CPL was not 0.372 WBINVD