Mark Kettenis <mark.kette...@xs4all.nl> wrote: > But maybe the default rdtsc() should include the lfence. And then we > could have rdtsc_unordered() for this cases that don't care about > ordering.
Right. But I don't like the word 'order', because it is too vague. There are layers of ordering, speculation, asyncronous execution, etc. and lfence just deals with some of them. > As I wrote in my first mail, cpu_rnd_messybits() may want to use that. > And maybe one of the network stack people should investigate what the > impact of having the fence in the timecounter is? cpu_rnd_messybits is indifferent. It is amusing to capture some speculation side effect, but if we don't, it isn't the end of the world. A few days ago, we didn't even know this aspect existed...
