[PATCH] powerpc: Allow selection of CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
From: Christophe Leroy <hidden>
Date: 2018-04-17 10:49:11
Also in:
lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
This option does dead code and data elimination with the linker by
compiling with -ffunction-sections -fdata-sections and linking with
--gc-sections.
By selecting this option on mpc885_ads_defconfig,
vmlinux LOAD segment size gets reduced by 10%
Program Header before the patch:
LOAD off 0x00010000 vaddr 0xc0000000 paddr 0x00000000 align 2**16
filesz 0x0036eda4 memsz 0x0038de04 flags rwx
Program Header after the patch:
LOAD off 0x00010000 vaddr 0xc0000000 paddr 0x00000000 align 2**16
filesz 0x00316da4 memsz 0x00334268 flags rwx
Signed-off-by: Christophe Leroy <redacted>
---
arch/powerpc/Kconfig | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 8fe4353be5e3..e1fac49cf465 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig@@ -888,6 +888,14 @@ config PPC_MEM_KEYS If unsure, say y. +config PPC_UNUSED_ELIMINATION + bool "Eliminate unused functions and data from vmlinux" + default n + select LD_DEAD_CODE_DATA_ELIMINATION + help + Select this to do dead code and data elimination with the linker + by compiling with -ffunction-sections -fdata-sections and linking + with --gc-sections. endmenu config ISA_DMA_API
--
2.13.3