4 ms·
https://docs.kernel.org/x86/orc-unwinder.html https://docs.kernel.org/x86/orc-unwinder.html (which I found when looking up ORC, as mentioned in this thread) has
by evmar 4y ago
https://docs.kernel.org/x86/orc-unwinder.html https://docs.kernel.org/x86/orc-unwinder.html (which I found when looking up ORC, as mentioned in this thread) has some stats for the Linux kernel on the cost of frame pointers: "5-10%" and "3.49% more cache misses with
framepointer enabled and 6.59% more cycles".
Between this, the various sorts of C language safety checks compilers have been slowly adding, and all the spectre-related defenses, it really does feel like performance is getting slowly consumed by a series of single-digit percentage tweaks.
- mepian 4y agoIt's just the time to pay the piper finally arriving, the computer industry ignored security in favor of performance for far too long.
- nullc 4y ago> the computer industry ignored security in favor of performance for far too long Doesn't including an explicit, predictable, frame pointer make life moderately easier for shell code?
- bravetraveler 4y agoI agree -- it's easy to think that a few percent here/there don't hurt, but there's no global context on this. Team A takes away ~4% here, B goes on to do ~3%, and so on and so forth. In only five of these, and consider the chains of Pythonic imports you've seen for example, you've lost roughly a quarter of your performance. (grant me an additive/compounding? nature) This is assuming that the measurements taken in a vacuum even hold up to reality. I've seen reports for misc. other things in the 20% range, so my confidence is remarkably low. I'm not against making it easier, but I don't think everyone always need to be ready for profiling. Making opting in easier lets us ignore the hand-wavy numbers. edit: To add, the simplification of this performance cost down to percentages completely ignores scale. It's a deceptive statistician's trick. Your favorite browser accidentally releasing a debug/verbose-logging version that consumed in the range of 1-10% more power globally would be significant.
- ilyt 4y agoAnd each 2-3% reduction is reason that the following 2-3% reduction asks "the previous one was accepted, why not accept this one?"