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Finding a profiler that works, damnit

Finding a profiler that works, damnit

Posted Mar 24, 2010 10:31 UTC (Wed) by nix (subscriber, #2304)
In reply to: Finding a profiler that works, damnit by ringerc
Parent article: KVM, QEMU, and kernel project management

Virtually everything that reads debugging information knows how to use external debug files, both in /usr/lib/debug/$PATH.dbg format and in /usr/lib/debug/$BUILD_ID format, because both of these have been used by widely-released distributions (Ubuntu and Red Hat have both used various versions of these).

It's been some years since I've come across any tool that reads DWARF2 that doesn't know about at least one of these, and in the last year or so everything has learnt about both (including perf).

Since pretty much every distribution is now compiling everything with separated debugging information, anything that doesn't support it isn't going to be particularly useful.

Outside rare code (e.g. the occasional garbage collector) that actually needs frame pointers for correct operation, -fno-omit-frame-pointer is needless, and using -fomit-frame-pointer instead gives a substantial speedup on many common platforms. IIRC it's the default on x86-64, but I don't have a recent GCC source tree here so I can't be sure...


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