A 20x speedup as reported here is not that unusual in my experience. If I work on optimizing something which has never had detailed performance analysis, I expect to achieve 3x to 10x speedups in most cases. Even 100x is not really rare.<p>I once found a similar thing in a commercial setting. A program had been written which could set one bit in a shared memory region for use as a feature flag. It was slowly expanded in use until it was being run thousands of times a day on hundreds of very expensive computers. I wrote a replacement program which read commands from a file and set all the bits in one invocation. This saved well over 100k USD per year if you just added up the cost of computer time without staffing. I imagine this APT fix is worth more than that.