MOSI protocol
Encyclopedia
The MOSI protocol is an extension of the basic MSI
cache coherency
protocol. It adds the Owned state, which indicates that the current processor owns this block, and will service requests from other processors for the block.
For any given pair of caches, the permitted states of a given cache line are as follows:
MSI protocol
The MSI protocol is a basic Cache coherence protocol that is used in multiprocessor systems. As with other cache coherency protocols, the letters of the protocol name identify the possible states in which a cache line can be. So, for MSI, each block contained inside a cache can have one of three...
cache coherency
Cache coherency
In computing, cache coherence refers to the consistency of data stored in local caches of a shared resource.When clients in a system maintain caches of a common memory resource, problems may arise with inconsistent data. This is particularly true of CPUs in a multiprocessing system...
protocol. It adds the Owned state, which indicates that the current processor owns this block, and will service requests from other processors for the block.
For any given pair of caches, the permitted states of a given cache line are as follows:
| M | O | S | I | |
|---|---|---|---|---|
| M | ||||
| O | ||||
| S | ||||
| I |
See also
- Coherence protocol
- MSI protocolMSI protocolThe MSI protocol is a basic Cache coherence protocol that is used in multiprocessor systems. As with other cache coherency protocols, the letters of the protocol name identify the possible states in which a cache line can be. So, for MSI, each block contained inside a cache can have one of three...
- MESI protocolMESI protocolThe MESI protocol is a widely used cache coherency and memory coherence protocol. It is the most common protocol which supports write-back cache...
- MOESI protocolMOESI protocolIn computing, MOESI is a full cache coherency protocol that encompasses all of the possible states commonly used in other protocols. In addition to the four common MESI protocol states, there is a fifth "Owned" state representing data that is both modified and shared. This avoids the need to...