Re: INFO: rcu detected stall in sys_kill

[Nick Desaulniers]

On Thu, Jan 9, 2020 at 9:23 AM Dmitry Vyukov <dvyukov@xxxxxxxxxx> wrote:
>
> On Thu, Jan 9, 2020 at 6:17 PM Nick Desaulniers <ndesaulniers@xxxxxxxxxx> 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. :-/

-- 
Thanks,
~Nick Desaulniers