April 24th, 1998
Author: Ian Philp
Commodity OS Bypass and Flow Control Issues
Slide 1 – Commodity OS Bypass and Flow Control Issues
- Network Engineering Group
- Los Alamos National Laboratory
- SOS DVS Workshop
- March 30 – April 1, 1998
Slide 2 – OS Bypass
- latency
- avoid system calls and interrupts
- requires NIC to mux/demux application messages
- bandwidth
- avoid memory-memory copies
- VIA and ST are both OS bypass solutions
- provide interrupt and polling interface
- coalesce interrupts
Slide 3 – OS Bypass and Flow Control
- tradeoff between
- price of NIC
- potential performance improvement
- flow control on the NIC
- decouples progress of messages from application scheduling on CPU
Slide 4 – Flow Control and ULP Issues
- Sender
- Receiver
- MPI_ISend()
- compute()
- MPI_IRECV()
- Data with NIC
- flow control (ST)
- Data with appl.
- flow control (VIA)
- NIC
- request-to-send
- clear-to-send
Slide 5 – VIA and ST APIs
- VIA
- ST
- MPI
- sockets
- MPI
- sockets
- VIA
- VIA
- application
- application
- ST
- host
- host
- NIC
- NIC