> We've spent quite a lot of effort explaining the problems with the
> utrace/uprobes dependency
Can you provide some links to discussion about these specifics: ?
> (especially the issues of having to pull the
> process symbol table into the kernel
User-space symbol tables are made available to the systemtap module
only if it is required by the script - if it performs symbolic
address or backtrace type lookups.
> and of having the kernel actually
> execute the compiled code to do the traps
Like in dtrace, instrumentation is run within the kernel because
having user-space processes instrument each other is too disruptive.
We're looking for microsecond-level probe effect, not something
involving multiple context switches, indirect address space accesses,
and so on.