Re: [PATCH v2 0/4] riscv: enable HAVE_LD_DEAD_CODE_DATA_ELIMINATION

Nick Desaulniers
2023-06-20T20:47:31Z

On Tue, Jun 20, 2023 at 4:41 PM Palmer Dabbelt <palmer@dabbelt.com> wrote:
>
> On Tue, 20 Jun 2023 13:32:32 PDT (-0700), ndesaulniers@google.com wrote:
> > On Tue, Jun 20, 2023 at 4:13 PM Conor Dooley <conor@kernel.org> wrote:
> >>
> >> On Tue, Jun 20, 2023 at 04:05:55PM -0400, Nick Desaulniers wrote:
> >> > On Mon, Jun 19, 2023 at 6:06 PM Palmer Dabbelt <palmer@dabbelt.com> wrote:
> >> > > On Thu, 15 Jun 2023 06:54:33 PDT (-0700), Palmer Dabbelt wrote:
> >> > > > On Wed, 14 Jun 2023 09:25:49 PDT (-0700), jszhang@kernel.org wrote:
> >> > > >> On Wed, Jun 14, 2023 at 07:49:17AM -0700, Palmer Dabbelt wrote:
> >> > > >>> On Tue, 23 May 2023 09:54:58 PDT (-0700), jszhang@kernel.org wrote:
> >>
> >> > > >> Commit 3b90b09af5be ("riscv: Fix orphan section warnings caused by
> >> > > >> kernel/pi") touches vmlinux.lds.S, so to make the merge easy, this
> >> > > >> series is based on 6.4-rc2.
> >> > > >
> >> > > > Thanks.
> >> > >
> >> > > Sorry to be so slow here, but I think this is causing LLD to hang on
> >> > > allmodconfig. I'm still getting to the bottom of it, there's a few
> >> > > other things I have in flight still.
> >> >
> >> > Confirmed with v3 on mainline (linux-next is pretty red at the moment).
> >> > https://lore.kernel.org/linux-riscv/20230517082936.37563-1-falcon@tinylab.org/
> >>
> >> Just FYI Nick, there's been some concurrent work here from different
> >> people working on the same thing & the v3 you linked (from Zhangjin) was
> >> superseded by this v2 (from Jisheng).
> >
> > Ah! I've been testing the deprecated patch set, sorry I just looked on
> > lore for "dead code" on riscv-linux and grabbed the first thread,
> > without noticing the difference in authors or new version numbers for
> > distinct series. ok, nevermind my noise. I'll follow up with the
> > correct patch set, sorry!
>
> Ya, I hadn't even noticed the v3 because I pretty much only look at
> patchwork these days. Like we talked about in IRC, I'm going to go test
> the merge of this one and see what's up -- I've got it staged at
> <https://git.kernel.org/pub/scm/linux/kernel/git/palmer/linux.git/commit/?h=for-next&id=1bd2963b21758a773206a1cb67c93e7a8ae8a195>,
> though that won't be a stable hash if it's actually broken...

Ok, https://lore.kernel.org/linux-riscv/20230523165502.2592-1-jszhang@kernel.org/
built for me. If you're seeing a hang, please let me know what
version of LLD you're using and I'll build that tag from source to see
if I can reproduce, then bisect if so.

$ ARCH=riscv LLVM=1 /usr/bin/time -v make -j128 allmodconfig vmlinux
...
Elapsed (wall clock) time (h:mm:ss or m:ss): 2:35.68
...

Tested-by: Nick Desaulniers <ndesaulniers@google.com> # build

>
> >
> >>
> >> Cheers,
> >> Conor.
> >
> >
> >
> > --
> > Thanks,
> > ~Nick Desaulniers

--
Thanks,
~Nick Desaulniers