Messages in this thread | | | From | Alexander Potapenko <> | Date | Fri, 10 Jan 2020 09:37:06 +0100 | Subject | Re: INFO: rcu detected stall in sys_kill |
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On Thu, Jan 9, 2020 at 6:39 PM 'Nick Desaulniers' via kasan-dev <kasan-dev@googlegroups.com> wrote: > > On Thu, Jan 9, 2020 at 9:23 AM Dmitry Vyukov <dvyukov@google.com> wrote: > > > > On Thu, Jan 9, 2020 at 6:17 PM Nick Desaulniers <ndesaulniers@google.com> wrote: > > > I disabled loop unrolling and loop unswitching in LLVM when the loop > > > contained asm goto in: > > > https://github.com/llvm/llvm-project/commit/c4f245b40aad7e8627b37a8bf1bdcdbcd541e665 > > > I have a fix for loop unrolling in: > > > https://reviews.llvm.org/D64101 > > > that I should dust off. I haven't looked into loop unswitching yet. > > > > c4f245b40aad7e8627b37a8bf1bdcdbcd541e665 is in the range between the > > broken compiler and the newer compiler that seems to work, so I would > > assume that that commit fixes this. > > We will get the final stamp from syzbot hopefully by tomorrow. > > How often do you refresh the build of Clang in syzbot? Is it manual? I > understand the tradeoffs of living on the tip of the spear, but > c4f245b40aad7e8627b37a8bf1bdcdbcd541e665 is 6 months old. So upstream > LLVM could be regressing more often, and you wouldn't notice for 1/2 a > year or more. :-/ KMSAN used to be the only user of Clang on syzbot, so I didn't bother too often. Now that there are other users, we'll need a better strategy. Clang revisions I've been picking previously came from Chromium's Clang distributions. This is nice, because Chromium folks usually pick a revision that has been extensively tested at Google already, plus they make sure Chromium tests also pass. They don't roll the compiler often, however (typically once a month or two, but this time there were holidays, plus some nasty breakages). > -- > Thanks, > ~Nick Desaulniers > > -- > You received this message because you are subscribed to the Google Groups "kasan-dev" group. > To unsubscribe from this group and stop receiving emails from it, send an email to kasan-dev+unsubscribe@googlegroups.com. > To view this discussion on the web visit https://groups.google.com/d/msgid/kasan-dev/CAKwvOdkh8CV0pgqqHXknv8%2BgE2ovoKEV_m%2BqiEmWutmLnra3%3Dg%40mail.gmail.com.
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