Nivedita Singhvi wrote:
Rick Jones wrote:
These loopback driver SMP optimizations are starting to really
driver me crazy.
Correct or not, I suspect there are a non-trivial number of folks out
there who use loopback performance as an indicator of over the network
performance or at least of stack path length (less driver).
I hope not the former. Given that loopback performance is
*significantly* faster than network performance, increasing the
performance of the loopback driver in these somewhat artificial
ways (that differ from the real network device path) simply
*increases* the inaccuracy of their testing and the conclusions
they can draw from it ;).
I suspect the idea is that if loopback on Platform A is faster than loopback on
Platform B, then over the network will be faster (or at least more efficient) on
Platform A than it is on Platform B.
It is indeed fraught with numerous pitfalls - different MTU's, shorticircuting
at different places etc etc.
I do not claim to condone (even if I'm sometimes forced into that situation
myself :( ) merely to explain.
As for the 512 CPU machine mentioned in another message, at the rate cores per
die may increase over the next few years, that may not really be all that large
a box... :)
rick jones
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