The thing that has me slightly worried is that there may be a source of nondeterminism buried in a library where we can't get at it that ends up influencing Servo a lot. Gulp, not much we can do other than try it and see. Computing is n experimental science and all that.
On Tue, Jun 4, 2019 at 7:15 PM Robert O'Callahan <rob...@ocallahan.org> wrote: > On Wed, Jun 5, 2019 at 4:16 AM Alan Jeffrey <ajeff...@mozilla.com> wrote: > >> We're interested in doing the experiment of how to increase the amount of >> determinism in a program like Servo where almost all the nondeterminism >> that's observable by Servo has a single cause (in Servo's case selecting on >> channels). There'll still be a lot of nondeterminism in the system (e.g. >> dependencies like rayon that do their own thread management) but hopefully >> not much that's observable within Servo, and in particular not much that >> causes intermittent WPT test failure. If this experiment works, there's >> then the question of what the overhead is compared to something like rr, my >> guess is that it'll be lower, but rr is very very good at its job, so it >> may be a hard target to beat! >> > > I think you'll easily beat rr overhead if your hypothesis is correct and > recording channel nondeterminism suffices to make replay actually work --- > even ignoring parallelism. > > It sounds like a great experiment and it'll be interesting to see how that > works out! > > Rob > -- > Su ot deraeppa sah dna Rehtaf eht htiw saw hcihw, efil lanrete eht uoy ot > mialcorp ew dna, ti ot yfitset dna ti nees evah ew; deraeppa efil eht. Efil > fo Drow eht gninrecnoc mialcorp ew siht - dehcuot evah sdnah ruo dna ta > dekool evah ew hcihw, seye ruo htiw nees evah ew hcihw, draeh evah ew > hcihw, gninnigeb eht morf saw hcihw taht. > _______________________________________________ dev-servo mailing list dev-servo@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-servo
