From 96dc819c2526f31c18adf2f793f01395493e71c3 Mon Sep 17 00:00:00 2001 From: Tao Liu Date: Thu, 6 Jan 2022 14:23:41 +0800 Subject: [PATCH] Set zstd as the default compression method for kdump initrd resolves: bz1896698 upstream: fedora conflict: none commit 0311f6e25bec9994de2c6b156b5a568583aa8aae Author: Tao Liu Date: Wed Jan 5 17:42:12 2022 +0800 Set zstd as the default compression method for kdump initrd zstd has better compression ratio and time consumption balance. When no customized compression method specified in kdump.conf, we will use zstd as the default compression method. **The test method: I installed kexec-tools with and without the patch, executing the following command for 4 times, and calculate the averange time: $ rm -f /boot/initramfs-*kdump.img && time kdumpctl rebuild && \ ls -ail /boot/initramfs-*kdump.img **The test result: Bare metal x86_64 machine: dracut with squash module zlib lzo xz lz4 zstd real 10.6282 11.0398 11.395 8.6424 10.1676 user 9.8932 11.9072 14.2304 2.8286 8.6468 sys 3.523 3.4626 3.6028 3.5 3.4942 size of kdump.img 30575616 31419392 27102208 36666368 29236224 dracut without squash module zlib lzo xz lz4 zstd real 9.509 19.4876 11.6724 9.0338 10.267 user 10.6028 14.516 17.8662 4.0476 9.0936 sys 2.942 2.9184 3.0662 2.9232 3.0662 size of kdump.img 19247949 19958120 14505056 21112544 17007764 PowerVM hosted ppc64le VM: dracut with squash module | dracut without sqaush module zlib zstd | zlib zstd real 10.6742 10.7572 | 9.7676 10.5722 user 18.754 19.8338 | 20.7932 13.179 sys 1.8358 1.864 | 1.637 1.663 | size of | kdump.img 36917248 35467264 | 21441323 19007108 **discussion zstd has a better compression ratio and time consumption balance. Acked-by: Coiby Xu Signed-off-by: Tao Liu Signed-off-by: Tao Liu --- kdump-lib.sh | 6 ++++++ kexec-tools.spec | 1 + mkdumprd | 4 ++++ mkfadumprd | 4 ++++ 4 files changed, 15 insertions(+) diff --git a/kdump-lib.sh b/kdump-lib.sh index fd51266..6415dda 100755 --- a/kdump-lib.sh +++ b/kdump-lib.sh @@ -443,6 +443,12 @@ is_wdt_active() return 1 } +have_compression_in_dracut_args() +{ + [[ "$(kdump_get_conf_val dracut_args)" =~ \ + (^|[[:space:]])--(gzip|bzip2|lzma|xz|lzo|lz4|zstd|no-compress|compress)([[:space:]]|$) ]] +} + # If "dracut_args" contains "--mount" information, use it # directly without any check(users are expected to ensure # its correctness). diff --git a/kexec-tools.spec b/kexec-tools.spec index 5655503..bb2f7e7 100644 --- a/kexec-tools.spec +++ b/kexec-tools.spec @@ -71,6 +71,7 @@ Requires: dracut >= 050 Requires: dracut-network >= 050 Requires: dracut-squash >= 050 Requires: ethtool +Requires: zstd Recommends: grubby BuildRequires: make BuildRequires: zlib-devel elfutils-devel glib2-devel bzip2-devel ncurses-devel bison flex lzo-devel snappy-devel libzstd-devel diff --git a/mkdumprd b/mkdumprd index d87d588..9c26ecc 100644 --- a/mkdumprd +++ b/mkdumprd @@ -431,6 +431,10 @@ done <<< "$(kdump_read_conf)" handle_default_dump_target +if ! have_compression_in_dracut_args; then + add_dracut_arg "--compress" "zstd" +fi + if [[ -n $extra_modules ]]; then add_dracut_arg "--add-drivers" "$extra_modules" fi diff --git a/mkfadumprd b/mkfadumprd index b890f83..16fdacc 100644 --- a/mkfadumprd +++ b/mkfadumprd @@ -62,6 +62,10 @@ if is_squash_available; then _dracut_isolate_args+=(--add squash) fi +if ! have_compression_in_dracut_args; then + _dracut_isolate_args+=(--compress zstd) +fi + if ! dracut --force --quiet "${_dracut_isolate_args[@]}" "$@" "$TARGET_INITRD"; then perror_exit "mkfadumprd: failed to setup '$TARGET_INITRD' with dump capture capability" fi