Well, if you use hardware-assist you can get 0% overhead with shared memory and without serializing cores. Unfortunately, only some chips expose the correct hardware.
In terms of other publicly available systems, UndoDB claims properties similar to rr and appears to use the same general approach based on talks I have seen from the creator, but I have no first hand information on its actual properties.
If only advertising would help more. Unfortunately for all companies in this business, few companies are willing to invest even a tiny amount in developer productivity let alone properly value it. For instance, do you know of any company that spends more than $20k/year per developer on tools to enhance software developer productivity? To go even further, how many companies would even consider spending the astronomical sum of $20k/year per developer on tools? Yet, a fully burdened developer is ~$200k/year, so, using the most basic business analysis of just cost savings (which undervalues to a mind-boggling degree), $20k/year is a mere 10% cost increase, but for some reason it is viewed as an astronomical and ridiculous price. In other sectors, businesses easily spend significant percentages of salary cost in tooling. EDA tools for EEs can run $50k/year, trucks for truck drivers amortize out to $30-50k/year, etc. Obviously, you need to justify a 10% cost increase with an appropriate return, but the fact that few companies even bother to do so is in my opinion the primary limiting factor on increased adoption of the techniques and technologies we are discussing since nobody values them.
What hardware supports shared memory record-and-replay in the presence of data races? I'm not aware of any widely available hardware that does this.
UndoDB's design is similar to rr but they use binary instrumentation at record time, so it's higher overhead than rr and a more complex implementation in some ways, but they don't depend on performance counters so they work on more architectures (AMD, ARM) and in any virtual guest.
It's certainly true that it's hard to get people to pay for debugging tools. On the other hand, some big-name companies spend tons of money on internal tooling, so at least some companies are willing to spend on developer productivity in general. I think certain classes of tools have "traditionally" been free and that mindset is hard to change, and the majority of companies are reluctant to spend money on developer productivity in general. I don't have great ideas to tackle this other than "keep making tools better and better until the wall cracks".
If you want to talk more off the record, feel free to contact me.
An example is ARM systems including an ETM component that supports data tracing. You connect an external trace probe, usually via JTAG, to receive the trace events. This technique usually uses read/write and control-flow state for reconstruction. This has the advantage of not requiring a recording from the beginning to reconstruct since you can correctly work backward from the final state, but requires higher data bandwidth and storage.
In terms of other publicly available systems, UndoDB claims properties similar to rr and appears to use the same general approach based on talks I have seen from the creator, but I have no first hand information on its actual properties.
If only advertising would help more. Unfortunately for all companies in this business, few companies are willing to invest even a tiny amount in developer productivity let alone properly value it. For instance, do you know of any company that spends more than $20k/year per developer on tools to enhance software developer productivity? To go even further, how many companies would even consider spending the astronomical sum of $20k/year per developer on tools? Yet, a fully burdened developer is ~$200k/year, so, using the most basic business analysis of just cost savings (which undervalues to a mind-boggling degree), $20k/year is a mere 10% cost increase, but for some reason it is viewed as an astronomical and ridiculous price. In other sectors, businesses easily spend significant percentages of salary cost in tooling. EDA tools for EEs can run $50k/year, trucks for truck drivers amortize out to $30-50k/year, etc. Obviously, you need to justify a 10% cost increase with an appropriate return, but the fact that few companies even bother to do so is in my opinion the primary limiting factor on increased adoption of the techniques and technologies we are discussing since nobody values them.