addr2line performance

[Tony Jones <tonyj@suse.de>]

Hi.

https://bugzilla.kernel.org/show_bug.cgi?id=218996#c1 mentions
"there are proposals to move this logic to being from a library again. 
I think the addr2line processing attempted is valiant but ultimately 
using a library will be best" (this was when LLVM addr2line support 
was already present),

Obviously the test patch mentioned in the above bug doesn't address 
the underlying performance issue, only better classifying a timeout 
error.

We have a customer bug complaining about the performance of addr2line.
I'm seeing cases where it's taking over 20 seconds wall clock to 
resolve certain addresses which obviously causes the io_timer to trip 
but the performance of the success path isn't great either.

Obviously BFD isn't an option and (for various reasons) we can't use 
LLVM for this specific distro so I'm looking at the performance
of addr2line.

Can someone point me to the prior "using a library" discussion 
referenced in the above bug or whatever the current thinking is.  I 
couldn't find anything searching the archive.

Thanks in advance!

Tony

-- 
Tony Jones
SUSE Kernel Performance Team