[$] Device-initiated I/O

Peer-to-peer DMA (P2PDMA) has been part ofthe kernel since the 4.20 release in 2018;it provides a framework that allows devices to transfer data between themselvesdirectly, without using system RAM for the transfer. At the 2025 LinuxStorage, Filesystem, Memory Management, and BPF Summit (LSFMM+BPF), StephenBates led a combined storage, filesystems, and memory-management session ondevice-initiated I/O, which is perhaps what P2PDMA is evolving toward. Twoyears ago, he led a session on P2PDMA at thesummit; this year's session was a brief update on P2PDMA with a lookat where it may be heading.