From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl1-f178.google.com ([209.85.214.178]:33276 "EHLO mail-pl1-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727328AbgCYT7E (ORCPT ); Wed, 25 Mar 2020 15:59:04 -0400 From: Nick Terrell Subject: [PATCH v3 5/8] usr: add support for zstd compressed initramfs Date: Wed, 25 Mar 2020 12:58:46 -0700 Message-Id: <20200325195849.407900-6-nickrterrell@gmail.com> In-Reply-To: <20200325195849.407900-1-nickrterrell@gmail.com> References: <20200325195849.407900-1-nickrterrell@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kbuild-owner@vger.kernel.org List-ID: To: Nick Terrell Cc: linux-kernel@vger.kernel.org, Chris Mason , linux-kbuild@vger.kernel.org, x86@kernel.org, gregkh@linuxfoundation.org, Petr Malat , Kees Cook , Kernel Team , Nick Terrell , Adam Borowski , Patrick Williams , rmikey@fb.com, mingo@kernel.org, Patrick Williams From: Nick Terrell * Add support for a zstd compressed initramfs. * Add compression for compressing built-in initramfs with zstd. I have tested this patch by boot testing with buildroot and QEMU. Specifically, I booted the kernel with both a zstd and gzip compressed initramfs, both built into the kernel and separate. I ensured that the correct compression algorithm was used. I tested on arm, aarch64, i386, and x86_64. This patch has been tested in production on aarch64 and x86_64 devices. Additionally, I have performance measurements from internal use in production. On an aarch64 device we saw 19 second boot time improvement from switching from lzma to zstd (27 seconds to 8 seconds). On an x86_64 device we saw a 9 second boot time reduction from switching from xz to zstd. Signed-off-by: Nick Terrell --- usr/Kconfig | 20 ++++++++++++++++++++ usr/Makefile | 1 + 2 files changed, 21 insertions(+) diff --git a/usr/Kconfig b/usr/Kconfig index bdf5bbd40727..43aca37d09b5 100644 --- a/usr/Kconfig +++ b/usr/Kconfig @@ -100,6 +100,15 @@ config RD_LZ4 Support loading of a LZ4 encoded initial ramdisk or cpio buffer If unsure, say N. +config RD_ZSTD + bool "Support initial ramdisk/ramfs compressed using ZSTD" + default y + depends on BLK_DEV_INITRD + select DECOMPRESS_ZSTD + help + Support loading of a ZSTD encoded initial ramdisk or cpio buffer. + If unsure, say N. + choice prompt "Built-in initramfs compression mode" depends on INITRAMFS_SOURCE != "" @@ -207,4 +216,15 @@ config INITRAMFS_COMPRESSION_LZ4 If you choose this, keep in mind that most distros don't provide lz4 by default which could cause a build failure. +config INITRAMFS_COMPRESSION_ZSTD + bool "ZSTD" + depends on RD_ZSTD + help + ZSTD is a compression algorithm targeting intermediate compression + with fast decompression speed. It will compress better than GZIP and + decompress around the same speed as LZO, but slower than LZ4. + + If you choose this, keep in mind that you may need to install the zstd + tool to be able to compress the initram. + endchoice diff --git a/usr/Makefile b/usr/Makefile index c12e6b15ce72..b1a81a40eab1 100644 --- a/usr/Makefile +++ b/usr/Makefile @@ -15,6 +15,7 @@ compress-$(CONFIG_INITRAMFS_COMPRESSION_LZMA) := lzma compress-$(CONFIG_INITRAMFS_COMPRESSION_XZ) := xzmisc compress-$(CONFIG_INITRAMFS_COMPRESSION_LZO) := lzo compress-$(CONFIG_INITRAMFS_COMPRESSION_LZ4) := lz4 +compress-$(CONFIG_INITRAMFS_COMPRESSION_ZSTD) := zstd obj-$(CONFIG_BLK_DEV_INITRD) := initramfs_data.o -- 2.25.1