Daniel Alley wrote:
> It is unlikely that the critical bottleneck of any applications will be on
> such a function.

But it can be in the function CALLING such a function, and said function 
will be completely missing from the backtrace.

Quoting your link 
[https://developer.arm.com/documentation/dui0774/k/Compiler-Command-line-Options/-fomit-frame-pointer---fno-omit-frame-pointer]:
> A function that does not use any stack space does not need to create a
> frame record, and leaves the frame pointer pointing to the caller's
> frame.

And that limitation makes -fno-omit-frame-pointer useless for the purpose 
for which it is being forced onto Fedora users.

The other limitation that I have mentioned is also documented there:
> There is a short time period at the beginning and end of a function where
> the frame pointer points to the frame record in the caller's frame.

That, too, means frame pointers cannot by design solve the problem which the 
change intends to solve with them.

        Kevin Kofler
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