Messages in this thread | | | Date | Sat, 22 Aug 2015 12:03:33 +0200 | From | Ingo Molnar <> | Subject | Re: [Regression v4.2 ?] 32-bit seccomp-BPF returned errno values wrong in VM? |
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* Denys Vlasenko <dvlasenk@redhat.com> wrote:
> It was nearly inevitable that something would break during untangling.
1)
So the 'chronic lack of compat, audit/noaudit and Wine testing' was certainly avoidable.
The problem wasn't the fact that something was bound to break, but the latency of finding these bugs. If we cannot reduce the latency so that bugs are caught early enough (before they reach mainline) then we shouldn't be doing such changes.
We are slowly adding tests for that in the x86 self-tests, but IMHO we should be more proactive than that.
2)
Another structural problem I saw occasionally was the attempt to characterise away regressions.
That's a 100% no-no: if a change breaks any user-space program, it does not matter how 'correct' a change is, how weird the user-space dependence and how rare the user-space program: the regression needs to be fixed either by going forward with a fix or by going backwards via reverting the change.
Thanks,
Ingo
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