From: Michael Ellerman <mpe@ellerman.id.au>
To: Ard Biesheuvel <ard.biesheuvel@linaro.org>,
linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org,
linuxppc-dev@lists.ozlabs.org, x86@kernel.org,
keescook@chromium.org, akpm@linux-foundation.org,
mingo@kernel.org, hpa@zytor.com, heiko.carstens@de.ibm.com,
benh@kernel.crashing.org, mmarek@suse.cz, rusty@rustcorp.com.au
Subject: Re: [PATCH 2/4] powerpc: enable text relative kallsyms for ppc64
Date: Thu, 21 Jan 2016 15:01:12 +1100 [thread overview]
Message-ID: <1453348872.468.6.camel@ellerman.id.au> (raw)
In-Reply-To: <1453280738-18721-3-git-send-email-ard.biesheuvel@linaro.org>
On Wed, 2016-01-20 at 10:05 +0100, Ard Biesheuvel wrote:
> This enables the newly introduced text-relative kallsyms support when
> building 64-bit targets. This cuts the size of the kallsyms address
> table in half, and drastically reduces the size of the PIE dynamic
> relocation section when building with CONFIG_RELOCATABLE=y (by about
> 3 MB for ppc64_defconfig)
>
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> ---
>
> Results for ppc64_defconfig:
>
> BEFORE:
> =======
> $ size vmlinux
> text data bss dec hex filename
> 19827996 2008456 849612 22686064 15a2970 vmlinux
>
> $ readelf -S .tmp_kallsyms2.o
> There are 9 section headers, starting at offset 0x4513f8:
>
> Section Headers:
> [Nr] Name Type Address Offset
> Size EntSize Flags Link Info Align
> ...
> [ 4] .rodata PROGBITS 0000000000000000 00000100
> 00000000001fcf00 0000000000000000 A 0 0 256
> [ 5] .rela.rodata RELA 0000000000000000 001fd1d8
> 0000000000254220 0000000000000018 I 7 4 8
> [ 6] .shstrtab STRTAB 0000000000000000 001fd000
> 0000000000000039 0000000000000000 0 0 1
> ...
>
> $ ls -l arch/powerpc/boot/zImage
> -rwxrwxr-x 2 ard ard 7533160 Jan 20 08:43 arch/powerpc/boot/zImage
>
> AFTER:
> ======
> $ size vmlinux
> text data bss dec hex filename
> 16979516 2009992 849612 19839120 12eb890 vmlinux
>
> $ readelf -S .tmp_kallsyms2.o
> There are 8 section headers, starting at offset 0x199bb0:
>
> Section Headers:
> [Nr] Name Type Address Offset
> Size EntSize Flags Link Info Align
> ...
> [ 4] .rodata PROGBITS 0000000000000000 00000100
> 0000000000199900 0000000000000000 A 0 0 256
> [ 5] .shstrtab STRTAB 0000000000000000 00199a00
> 0000000000000034 0000000000000000 0 0 1
> ...
>
> $ ls -l arch/powerpc/boot/zImage
> -rwxrwxr-x 2 ard ard 6985672 Jan 20 08:45 arch/powerpc/boot/zImage
Nice space saving, thanks very much.
I've booted this on a bunch of machines and it seems to be working fine.
Tested-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
cheers
next prev parent reply other threads:[~2016-01-21 4:01 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-20 9:05 [PATCH 0/4] support for text-relative kallsyms table Ard Biesheuvel
2016-01-20 9:05 ` [PATCH 1/4] kallsyms: add support for relative offsets in kallsyms address table Ard Biesheuvel
2016-01-20 19:13 ` Kees Cook
2016-01-20 9:05 ` [PATCH 2/4] powerpc: enable text relative kallsyms for ppc64 Ard Biesheuvel
2016-01-21 4:01 ` Michael Ellerman [this message]
2016-01-20 9:05 ` [PATCH 3/4] s390: enable text relative kallsyms for 64-bit targets Ard Biesheuvel
2016-01-20 9:43 ` Heiko Carstens
2016-01-20 10:04 ` Ard Biesheuvel
2016-01-20 10:17 ` Heiko Carstens
2016-01-20 10:18 ` Ard Biesheuvel
2016-01-20 9:05 ` [PATCH 4/4] x86_64: " Ard Biesheuvel
2016-01-20 19:12 ` Kees Cook
2016-01-20 10:33 ` [PATCH 0/4] support for text-relative kallsyms table Ingo Molnar
2016-01-20 11:50 ` Arnd Bergmann
2016-01-21 5:10 ` Rusty Russell
2016-01-21 6:45 ` Ard Biesheuvel
2016-01-21 8:32 ` Ard Biesheuvel
2016-01-27 3:46 ` Rusty Russell
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