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From: ebiederm@xmission.com (Eric W. Biederman)
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: Tejun Heo <tj@kernel.org>, hacklu <embedway.linux@gmail.com>,
	linux-kernel@vger.kernel.org
Subject: [PATCH 4/4] x86 boot: Tell ld the kernel doesn't want 2MB file offset alignment.
Date: Sun, 08 Jul 2012 23:56:17 -0700	[thread overview]
Message-ID: <871ukl5soe.fsf_-_@xmission.com> (raw)
In-Reply-To: <87fw915sv4.fsf_-_@xmission.com> (Eric W. Biederman's message of "Sun, 08 Jul 2012 23:52:15 -0700")


By default ld uses 2MB pages and aligns our 3 program segments in the
file on 2MB boundaries, creating unnecessarily large uncompressed
vmlinux files.

Solve this by passing -z max-page-size 4096 to ld.

In my test x86_64 SMP test configuration with CONFIG_DEBUG_RODATA
enabled, this reduces the size of vmlinux by roughly 5MB from 15141772
bytes to 10210188 bytes.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
 arch/x86/Makefile |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index 1f25214..b5b31c3 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -120,7 +120,7 @@ avx_instr := $(call as-instr,vxorps %ymm0$(comma)%ymm1$(comma)%ymm2,-DCONFIG_AS_
 KBUILD_AFLAGS += $(cfi) $(cfi-sigframe) $(cfi-sections) $(asinstr) $(avx_instr)
 KBUILD_CFLAGS += $(cfi) $(cfi-sigframe) $(cfi-sections) $(asinstr) $(avx_instr)
 
-LDFLAGS := -m elf_$(UTS_MACHINE)
+LDFLAGS := -m elf_$(UTS_MACHINE) -z max-page-size=4096
 
 # Speed up the build
 KBUILD_CFLAGS += -pipe
-- 
1.7.5.4


  parent reply	other threads:[~2012-07-09  6:56 UTC|newest]

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-05-17  5:56 why the decompressed procedure move kernel from address 0x100000(1M) to 0x1000000(16M) +x hacklu
2012-06-02 23:48 ` Eric W. Biederman
2012-06-03  3:10   ` H. Peter Anvin
2012-06-03  8:41     ` Eric W. Biederman
2012-06-03 13:01       ` H. Peter Anvin
2012-06-03 20:30         ` [PATCH 1/2] x86, boot: Don't overlap the compressed and non-compressed image Eric W. Biederman
2012-06-03 20:32           ` [PATCH 2/2] x86, boot: Optimize the elf header handling Eric W. Biederman
2012-07-01 14:56             ` [tip:x86/boot] " tip-bot for Eric W. Biederman
2012-07-01 15:04             ` [PATCH 2/2] " H. Peter Anvin
2012-07-01 15:34               ` H. Peter Anvin
2012-07-01 16:08                 ` Eric W. Biederman
2012-07-01 16:11                   ` H. Peter Anvin
2012-07-01 16:26                     ` Eric W. Biederman
2012-07-01 16:44                       ` H. Peter Anvin
2012-07-01 17:09                         ` Eric W. Biederman
2012-07-01 17:15                           ` H. Peter Anvin
2012-07-01 18:25                             ` Eric W. Biederman
2012-07-01 18:37                               ` H. Peter Anvin
2012-07-01 19:20                                 ` Eric W. Biederman
2012-07-01 19:23                                   ` H. Peter Anvin
2012-07-01 20:40                                     ` Eric W. Biederman
2012-07-01 20:52                                       ` H. Peter Anvin
2012-07-09  6:50                                         ` Eric W. Biederman
2012-07-09  6:52                                           ` [PATCH 1/4] x86 boot: Jump to the entry point address in the elf header Eric W. Biederman
2012-07-09  6:53                                             ` [PATCH 2/4] x86 boot: Optimize the elf header handling Eric W. Biederman
2012-07-09  6:55                                             ` [PATCH 3/4] x86 boot: When building vmlinux.bin properly precompute the memory image Eric W. Biederman
2012-07-09  6:56                                             ` Eric W. Biederman [this message]
2012-07-09  6:59                                             ` [PATCH 1/4] x86 boot: Jump to the entry point address in the elf header Eric W. Biederman
2012-07-02 16:56                                 ` [PATCH 2/2] x86, boot: Optimize the elf header handling Tejun Heo
2012-07-09  7:03                                   ` Eric W. Biederman
2012-07-01  2:23           ` [PATCH 1/2] x86, boot: Don't overlap the compressed and non-compressed image Eric W. Biederman
2012-07-01  2:32             ` H. Peter Anvin
2012-07-01  5:22               ` Eric W. Biederman
2012-07-01 14:55           ` [tip:x86/boot] x86, boot: Don' t " tip-bot for Eric W. Biederman

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