[PATCH] riscv: disable HAVE_LD_DEAD_CODE_DATA_ELIMINATION for LLD

[Nick Desaulniers]

Linking allyesconfig with ld.lld-17 with CONFIG_DEAD_CODE_ELIMINATION=y
takes hours.  Assuming this is a performance regression that can be
fixed, tentatively disable this for now so that allyesconfig builds
don't start timing out.  If and when there's a fix to ld.lld, this can
be converted to a version check instead so that users of older but still
supported versions of ld.lld don't hurt themselves by enabling
CONFIG_LD_DEAD_CODE_DATA_ELIMINATION=y.

Link: https://github.com/ClangBuiltLinux/linux/issues/1881
Reported-by: Palmer Dabbelt <palmer@xxxxxxxxxxx>
Suggested-by: Nathan Chancellor <nathan@xxxxxxxxxx>
Signed-off-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
---
Hi Jisheng, would you mind sending a v3 with this patch on top/at the
end of your patch series?

 arch/riscv/Kconfig | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 8effe5bb7788..0573991e9b78 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -116,7 +116,8 @@ config RISCV
 	select HAVE_KPROBES if !XIP_KERNEL
 	select HAVE_KPROBES_ON_FTRACE if !XIP_KERNEL
 	select HAVE_KRETPROBES if !XIP_KERNEL
-	select HAVE_LD_DEAD_CODE_DATA_ELIMINATION
+	# https://github.com/ClangBuiltLinux/linux/issues/1881
+	select HAVE_LD_DEAD_CODE_DATA_ELIMINATION if !LD_IS_LLD
 	select HAVE_MOVE_PMD
 	select HAVE_MOVE_PUD
 	select HAVE_PCI
-- 
2.41.0.162.gfafddb0af9-goog


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