Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Thomas =?utf-8?q?Wei=C3=9Fschuh?= <linux@weissschuh.net>
Date:   Tue, 27 Dec 2022 16:01:02 +0000
Subject: [PATCH v2 6/8] objtool: optimize layout of struct symbol
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 8bit
Message-Id: <20221216-objtool-memory-v2-6-17968f85a464@weissschuh.net>
References: <20221216-objtool-memory-v2-0-17968f85a464@weissschuh.net>
In-Reply-To: <20221216-objtool-memory-v2-0-17968f85a464@weissschuh.net>
To:     Josh Poimboeuf <jpoimboe@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>
Cc:     linux-kernel@vger.kernel.org,
        Thomas =?utf-8?q?Wei=C3=9Fschuh?= <linux@weissschuh.net>
Precedence: bulk

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