[PATCH] D26130: [ELF] - Implemented --symbol-ordering-file option.

[George Rimar via llvm-commits]

>OK, I think I am able to test this and show it can improve page faults.
>
>The script I used is attached. To get these crazy sampling rates I did
>
>echo 100 > /proc/sys/kernel/perf_cpu_time_max_percent
>echo 200000 >  /proc/sys/kernel/perf_event_max_sample_rate
>
>I also patched llvm so the symbolizer would print all symbols,
>including data and ifunc (also attached).
>
>With that "clang --help" goes from 293 page faults to 196 page faults.
>
>The time difference is from 0.002217410 to 0.001884017 seconds. Those
>are small but reproducible numbers since perf report a variance of
>0.29%.
>
>I will check what I can get with firefox.
>
>Cheers,
>Rafael

That was the place where I stuck today - was unable to get symbol file for firefox,
as it does not have static build and script produced empty symbol file always.

Looking on the updated script seems you use shared clang build ?

George.