Messages in this thread | | | Date | Thu, 10 Jul 2008 14:18:22 -0400 | From | "Frank Ch. Eigler" <> | Subject | Re: [RFC] simple dprobe like markers for the kernel |
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Hi -
On Thu, Jul 10, 2008 at 11:30:17AM -0400, Theodore Tso wrote:
> [...] When you said a tool could determine if the tracepoint had > gotten optimized away, or the variables were no longer present, I > assume you meant at compile time, right? So with the right tool > built into the kbuild infrastructure, if we could simply print > warnings when tracepoints had gotten optimized away [...]
It will be interesting to see how frequently such a warning appears for a good suite of such mini markers, on a diversity of architectures and compilers. Such data can help pronounce judgement on this approach.
> P.S. When you said that the current kernel markers are "a bit > heavyweight", how bad are they in practice? Hundreds of cycles? More?
Good question. The only performance measurements I have seen posted indicate negligible effects.
- FChE
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