How are data accessed in computer systems? #

Linux Storage Stack Diagram #

Source: Wikipedia

Direct Access (DAX) I/O Path #

Source: Pmem.io

Source: StorageReview

Tiered-memory I/O Path #

Source: StorageReview

CXL I/O Path #

Source: ACM

Source: Semiconductor Engineering

Source: CXL Consortium

Key-Value SSD I/O Path #

Source: SemanticScholar

How does DMA work? #

What is PCIe root? What role does it play in transferring data to/from PCIe-attached devices? #