# Buffers & SLRU (The Page Nudges) These are the most common LWLocks. They occur when two elephants are trying to look at the same **[[Structures/Page|Page]]** in the Shared Buffer brain at the same time. ![[BtreeVacuum]] ![[BufferContent]] ![[BufferMapping]] ![[CommitTs]] ![[CommitTsBuffer]] ![[CommitTsSLRU]] ![[ControlFile]] ![[LogicalRepWorker]] ![[RelationMapping]] ![[RelCacheInit]] ![[SerialBuffer]] ![[SerialSLRU]] ![[SharedTidBitmap]] ![[SharedTupleStore]] ![[SubtransBuffer]] ![[SubtransSLRU]] ![[XactBuffer]] ![[XactSLRU]] ![[XactTruncation]]