2022-02-09 10:04:11

by Nathan Chancellor

[permalink] [raw]
Subject: [PATCH] MIPS: Malta: Enable BLK_DEV_INITRD

This configuration is useful for boot testing malta_defconfig in QEMU
with just a simple cpio initrd, instead of a full ext4 rootfs.

This results in an increase of ~164KB of vmlinux (with GCC 11.2.0):

$ diskus vmlinux.before
11.19 MB (11,194,368 bytes)

$ diskus vmlinux.after
11.36 MB (11,358,208 bytes)

This size increase comes from the fact that usr/Kconfig is sourced when
CONFIG_BLK_DEV_INITRD is enabled, which defaults to supporting several
decompression algorithms for compressed initrds. This seems like a
reasonable tradeoff but these configurations could be disabled in the
future if there are complaints about the size increase.

Signed-off-by: Nathan Chancellor <[email protected]>
---
arch/mips/configs/malta_defconfig | 1 +
1 file changed, 1 insertion(+)

diff --git a/arch/mips/configs/malta_defconfig b/arch/mips/configs/malta_defconfig
index 3321bb576944..3456ac8ded6c 100644
--- a/arch/mips/configs/malta_defconfig
+++ b/arch/mips/configs/malta_defconfig
@@ -4,6 +4,7 @@ CONFIG_HIGH_RES_TIMERS=y
CONFIG_LOG_BUF_SHIFT=15
CONFIG_NAMESPACES=y
CONFIG_RELAY=y
+CONFIG_BLK_DEV_INITRD=y
CONFIG_EXPERT=y
# CONFIG_COMPAT_BRK is not set
CONFIG_SLAB=y

base-commit: dfd42facf1e4ada021b939b4e19c935dcdd55566
--
2.35.1



2022-02-09 11:15:40

by Kees Cook

[permalink] [raw]
Subject: Re: [PATCH] MIPS: Malta: Enable BLK_DEV_INITRD

On Tue, Feb 08, 2022 at 12:17:26PM -0700, Nathan Chancellor wrote:
> This configuration is useful for boot testing malta_defconfig in QEMU
> with just a simple cpio initrd, instead of a full ext4 rootfs.
>
> This results in an increase of ~164KB of vmlinux (with GCC 11.2.0):
>
> $ diskus vmlinux.before
> 11.19 MB (11,194,368 bytes)
>
> $ diskus vmlinux.after
> 11.36 MB (11,358,208 bytes)
>
> This size increase comes from the fact that usr/Kconfig is sourced when
> CONFIG_BLK_DEV_INITRD is enabled, which defaults to supporting several
> decompression algorithms for compressed initrds. This seems like a
> reasonable tradeoff but these configurations could be disabled in the
> future if there are complaints about the size increase.
>
> Signed-off-by: Nathan Chancellor <[email protected]>

I'm all for having a regular way to test all defconfigs. So, FWIW:

Reviewed-by: Kees Cook <[email protected]>

-Kees

> ---
> arch/mips/configs/malta_defconfig | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/arch/mips/configs/malta_defconfig b/arch/mips/configs/malta_defconfig
> index 3321bb576944..3456ac8ded6c 100644
> --- a/arch/mips/configs/malta_defconfig
> +++ b/arch/mips/configs/malta_defconfig
> @@ -4,6 +4,7 @@ CONFIG_HIGH_RES_TIMERS=y
> CONFIG_LOG_BUF_SHIFT=15
> CONFIG_NAMESPACES=y
> CONFIG_RELAY=y
> +CONFIG_BLK_DEV_INITRD=y
> CONFIG_EXPERT=y
> # CONFIG_COMPAT_BRK is not set
> CONFIG_SLAB=y
>
> base-commit: dfd42facf1e4ada021b939b4e19c935dcdd55566
> --
> 2.35.1
>

--
Kees Cook

2022-02-09 18:55:00

by Thomas Bogendoerfer

[permalink] [raw]
Subject: Re: [PATCH] MIPS: Malta: Enable BLK_DEV_INITRD

On Tue, Feb 08, 2022 at 12:17:26PM -0700, Nathan Chancellor wrote:
> This configuration is useful for boot testing malta_defconfig in QEMU
> with just a simple cpio initrd, instead of a full ext4 rootfs.
>
> This results in an increase of ~164KB of vmlinux (with GCC 11.2.0):
>
> $ diskus vmlinux.before
> 11.19 MB (11,194,368 bytes)
>
> $ diskus vmlinux.after
> 11.36 MB (11,358,208 bytes)
>
> This size increase comes from the fact that usr/Kconfig is sourced when
> CONFIG_BLK_DEV_INITRD is enabled, which defaults to supporting several
> decompression algorithms for compressed initrds. This seems like a
> reasonable tradeoff but these configurations could be disabled in the
> future if there are complaints about the size increase.
>
> Signed-off-by: Nathan Chancellor <[email protected]>
> ---
> arch/mips/configs/malta_defconfig | 1 +
> 1 file changed, 1 insertion(+)

applied to mips-next.

Thomas.

--
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
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