[Beowulf] Intro question

Greg Lindahl lindahl at pbm.com
Mon Dec 8 20:08:08 EST 2008


On Mon, Dec 08, 2008 at 10:19:17AM -0500, Lawrence Stewart wrote:

> Well <of course> the NIC should read from cache or update the cache if the
> data happens to be there. Don't all well designed I/O systems do that?

There are a small number of systems that don't. Needless to say, it's
a bit confusing for library writers to get I/O right in that
circumstances.

BTW, any interconnect that sends messages using PIO sends from
cache. I wish people would invent a real receive-to-cache, since it
would be nice overhead reducer for small messages on InfiniPath -- a
small latency benefit (~ 7%), a bigger overhead benefit (~ 15%).

-- greg

_______________________________________________
Beowulf mailing list, Beowulf at beowulf.org
To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf

-- 
This message has been scanned for viruses and
dangerous content by MailScanner, and is
believed to be clean.



More information about the Beowulf mailing list