On Sun, Mar 17, 2019 at 5:35 PM Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote: > > On Sun, Mar 17, 2019 at 3:43 AM syzbot > <syzbot+660883c56e2fa65d4497@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > > > syzbot has bisected this bug to: > > > > commit c470abd4fde40ea6a0846a2beab642a578c0b8cd > > Author: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> > > Date: Sun Feb 19 22:34:00 2017 +0000 > > Heh. Yeah, I doubt it. > > It would probably be good if syzbot did some confidence testing before > bisecting. > > Don't get me wrong, "git bisect" is absolutely wonderful and has done > a ton to help us fix bugs, but bisection has one major downside: if > the bug you are bisecting isn't 100% repeatable, the bisection will go > off into the random weeds and give completely nonsensical results. > They won't even be *close*. What makes bisection so powerful is also > what makes it then completely random if there's even *one* mistaken > bisection point. > > So it would probably be good to test each bisection point at least > twice, and if they don't agree, report it as being unbisectable rather > than give a random "this is what introduced the problem". > > Hmm? Hi Linus, Please see https://github.com/google/syzkaller/blob/master/docs/syzbot.md#bisection it should answer all of your questions. It does 2 and more. And in this case it seems to be working as intended bisecting it to a release tag.