Thread: Re: JIT crash introduced by 6185c9737c with LLVM 14
Hi Jeff, On Fri, Jun 14, 2024 at 1:25 PM Jeff Davis <jeff@j-davis.com> wrot> > The following query causes a crash on an optimized build using LLVM 14: > > create table t(i int); > set jit_above_cost=0; > select count(*) from t; > > I bisected the crash to 6185c9737c. Thanks for the report. Will look into it. -- Thanks, Amit Langote
Hi Jeff, On Fri, Jun 14, 2024 at 2:57 PM Amit Langote <amitlangote09@gmail.com> wrote: > On Fri, Jun 14, 2024 at 1:25 PM Jeff Davis <jeff@j-davis.com> wrot> > > The following query causes a crash on an optimized build using LLVM 14: > > > > create table t(i int); > > set jit_above_cost=0; > > select count(*) from t; > > > > I bisected the crash to 6185c9737c. > > Thanks for the report. Will look into it. Would you please share more details about the crash (llvm build attributes, etc.) as I'm unable to reproduce this crash with libLLVM-14.so that I built from sources that I got at [1]. No luck even after building with -DLLVM_ENABLE_ASSERTIONS=ON. I'm building PG HEAD with --buildtype=release. -- Thanks, Amit Langote [1] https://github.com/llvm/llvm-project/releases/tag/llvmorg-14.0.6
Hi, On Mon, Jun 17, 2024 at 6:32 PM Amit Langote <amitlangote09@gmail.com> wrote: > Hi Jeff, > > On Fri, Jun 14, 2024 at 2:57 PM Amit Langote <amitlangote09@gmail.com> wrote: > > On Fri, Jun 14, 2024 at 1:25 PM Jeff Davis <jeff@j-davis.com> wrot> > > > The following query causes a crash on an optimized build using LLVM 14: > > > > > > create table t(i int); > > > set jit_above_cost=0; > > > select count(*) from t; > > > > > > I bisected the crash to 6185c9737c. > > > > Thanks for the report. Will look into it. > > Would you please share more details about the crash (llvm build > attributes, etc.) as I'm unable to reproduce this crash with > libLLVM-14.so that I built from sources that I got at [1]. No luck > even after building with -DLLVM_ENABLE_ASSERTIONS=ON. I'm building PG > HEAD with --buildtype=release. Also, could you please check if the crash still occurs after applying the attached patch which removes the changes that 6185c9737c made to files under src/backend/jit? (My colleague David Rowley offered to test it on a raspberrypi and on a x86_64 machine with libLLVM-14.so, but sees no crash using those steps.) -- Thanks, Amit Langote
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On Tue, 2024-06-18 at 15:11 +0900, Amit Langote wrote:
> Also, could you please check if the crash still occurs after applying
> the attached patch which removes the changes that 6185c9737c made to
> files under src/backend/jit?
>
> (My colleague David Rowley offered to test it on a raspberrypi and on
> a x86_64 machine with libLLVM-14.so, but sees no crash using those
> steps.)
My testcase was wrong because I was installing into the same
destination directory each time when bisecting (that shortcut normally
works but can cause problems with LLVM changes). When I install into a
fresh directory, it works.
There may (or may not) have been some bug in my original larger case,
but I'll have to re-investigate, and in any case I don't think your
commit was a problem.
Regards,
Jeff Davis
On Wed, Jun 19, 2024 at 3:20 AM Jeff Davis <pgsql@j-davis.com> wrote: > There may (or may not) have been some bug in my original larger case, > but I'll have to re-investigate, and in any case I don't think your > commit was a problem. There are some unresolved reports of crashes on ARM CPUs using LLVM 14 in particular. What is your CPU?
On Wed, Jun 19, 2024 at 11:03:11AM +1200, Thomas Munro wrote: > On Wed, Jun 19, 2024 at 3:20 AM Jeff Davis <pgsql@j-davis.com> wrote: >> There may (or may not) have been some bug in my original larger case, >> but I'll have to re-investigate, and in any case I don't think your >> commit was a problem. Okay, for now I have removed Amit's name as owner of this open item. > There are some unresolved reports of crashes on ARM CPUs using LLVM 14 > in particular. What is your CPU? But it looks like we still have something new to v17 in this case, so the item it still around, pending more investigation. -- Michael
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On Wed, Jun 19, 2024 at 8:52 AM Michael Paquier <michael@paquier.xyz> wrote: > On Wed, Jun 19, 2024 at 11:03:11AM +1200, Thomas Munro wrote: > > On Wed, Jun 19, 2024 at 3:20 AM Jeff Davis <pgsql@j-davis.com> wrote: > >> There may (or may not) have been some bug in my original larger case, > >> but I'll have to re-investigate, and in any case I don't think your > >> commit was a problem. Ok, thanks. > Okay, for now I have removed Amit's name as owner of this open item. > > > There are some unresolved reports of crashes on ARM CPUs using LLVM 14 > > in particular. What is your CPU? > > But it looks like we still have something new to v17 in this case, so > the item it still around, pending more investigation. +1. I was about to mark it as resolved, but this makes sense. -- Thanks, Amit Langote