reduce maximum memory usage

[PATCH v2 6/8] objtool: optimize layout of struct symbol

Posted by Thomas Weißschuh 2 years, 8 months ago

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@weissschuh.net>
---
 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 2b5becad5a0a..f41573ff1f8b 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;

-- 
2.39.0

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

Posted by tip-bot2 for Thomas Weißschuh 2 years, 7 months ago

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@weissschuh.net>
AuthorDate:    Tue, 27 Dec 2022 16:01:02 
Committer:     Josh Poimboeuf <jpoimboe@kernel.org>
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@weissschuh.net>
Link: https://lore.kernel.org/r/20221216-objtool-memory-v2-6-17968f85a464@weissschuh.net
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
---
 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;

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

Posted by tip-bot2 for Thomas Weißschuh 2 years, 7 months ago

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

Commit-ID:     55156d43d62124a92ab80c8f31661609465e257b
Gitweb:        https://git.kernel.org/tip/55156d43d62124a92ab80c8f31661609465e257b
Author:        Thomas Weißschuh <linux@weissschuh.net>
AuthorDate:    Tue, 27 Dec 2022 16:01:02 
Committer:     Josh Poimboeuf <jpoimboe@kernel.org>
CommitterDate: Mon, 30 Jan 2023 16:28:20 -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@weissschuh.net>
Link: https://lore.kernel.org/r/20221216-objtool-memory-v2-6-17968f85a464@weissschuh.net
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
---
 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;