Hi, I just tried to compile with this patch and `allyesconfig` except
COMPILE_TEST, FTRACE, KASAN, GCOV, and XFS [1].  It finishes with no
issue, and takes ~22 min and ~25 GiB.  BTW, the kernel panics during boot
even built with GCC, so I didn't do further tests :( .

Command used: ARCH=riscv LLVM=1 LLVM_IAS=1 make HOSTCC=gcc vmlinux -j16
Kernel version: commit 2734d6c1b1a0 ("Linux 5.14-rc2")
LLVM version: commit 1b61d837b9d0 ("[Inline] Add test for PR50589 (NFC)")
The `.config` file is attached.

[1] https://github.com/ClangBuiltLinux/linux/issues/1215

On 2021/7/20 5:25, Nick Desaulniers wrote:
> On Mon, Jul 19, 2021 at 1:53 PM Wende Tan <twd2.me@gmail.com> wrote:
>
> Consider adding a little more detail to the commit message.
>
> In our experience with other architectures, we've hit numerous
> compiler and kernel issues especially with allyesconfigs. Has that
> been your experience with riscv?  It would be good to know if you've
> hit issues with LTO plus certain configs, so that we have confirmation
> others have seen these issues and so that we can triage fixes.
>
>> Signed-off-by: Wende Tan <twd2.me@gmail.com>
>> ---
>>  arch/riscv/Kconfig | 2 ++
>>  1 file changed, 2 insertions(+)
>>
>> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
>> index 8fcceb8eda07..b593e5031c79 100644
>> --- a/arch/riscv/Kconfig
>> +++ b/arch/riscv/Kconfig
>> @@ -34,6 +34,8 @@ config RISCV
>>         select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
>>         select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
>>         select ARCH_SUPPORTS_HUGETLBFS if MMU
>> +       select ARCH_SUPPORTS_LTO_CLANG
>> +       select ARCH_SUPPORTS_LTO_CLANG_THIN
>>         select ARCH_USE_MEMTEST
>>         select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
>>         select ARCH_WANT_FRAME_POINTERS
>> --

-- 
Best wishes!
Sincerely,
twd2
https://twd2.me