[tip: objtool/core] objtool: Optimize layout of struct symbol

From: tip-bot2 for Thomas Weißschuh
Date: Sat Feb 04 2023 - 05:17:33 EST


The following commit has been merged into the objtool/core branch of tip:

Commit-ID: 21a899f9fc78be6b289ee4627bccadf560930eb5
Gitweb: https://git.kernel.org/tip/21a899f9fc78be6b289ee4627bccadf560930eb5
Author: Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
AuthorDate: Tue, 27 Dec 2022 16:01:02
Committer: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
CommitterDate: Wed, 01 Feb 2023 09:15:24 -08:00

objtool: Optimize layout of struct symbol

Reduce the size of struct symbol on x86_64 from 208 to 200 bytes.
This structure is allocated a lot and never freed.

This reduces maximum memory usage while processing vmlinux.o from
2919716 KB to 2917988 KB (-0.5%) on my notebooks "localmodconfig".

Signed-off-by: Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20221216-objtool-memory-v2-6-17968f85a464@xxxxxxxxxxxxxx
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
tools/objtool/include/objtool/elf.h | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/tools/objtool/include/objtool/elf.h b/tools/objtool/include/objtool/elf.h
index 1c90f0a..ad0024d 100644
--- a/tools/objtool/include/objtool/elf.h
+++ b/tools/objtool/include/objtool/elf.h
@@ -50,12 +50,11 @@ struct symbol {
GElf_Sym sym;
struct section *sec;
char *name;
- unsigned int idx;
- unsigned char bind, type;
+ unsigned int idx, len;
unsigned long offset;
- unsigned int len;
unsigned long __subtree_last;
struct symbol *pfunc, *cfunc, *alias;
+ unsigned char bind, type;
u8 uaccess_safe : 1;
u8 static_call_tramp : 1;
u8 retpoline_thunk : 1;