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Re: Implementing a generic binary trace interface.
On Fri, 2006-01-27 at 08:05 -0500, Frank Ch. Eigler wrote:
> > printf() of 6 64-bit integers, converted to ASCII averaged 2.5 usecs
> > [...] I expect a binary printf of 6 64-bit values to take between
> > 0.2 and 0.4 usecs based on a quick prototype. ASCII printf
> > performance could be improved too with a rewrite.
>
> That's still orders of magnitude higher than a single binary
> assignment.
Yes. It appears to be the buffer reservation and manipulation that is
expensive. I have some ideas how to speed it up. It is done wrong now
anyway using old-fashioned percpu code.
> This may be one of those situations where the runtime's
> assistance is neither helpful nor necessary.
It may also be that a few tweaks of the current code can speed up
everything and satisfy the requirement for a generic binary interface.
I prefer not to create some special case until we understand the whole
problem.
Martin