[Touch-packages] [Bug 1931725] Re: initramfs-tools & kernel: use zstd as the default compression method
How to revert to old compression method for initramfs? Generating image with zstd is extremely slow and takes long time on slow CPU. -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to initramfs-tools in Ubuntu. https://bugs.launchpad.net/bugs/1931725 Title: initramfs-tools & kernel: use zstd as the default compression method Status in Ubuntu on IBM z Systems: Fix Released Status in initramfs-tools package in Ubuntu: Fix Released Status in linux package in Ubuntu: Fix Released Status in linux-oracle package in Ubuntu: Fix Released Bug description: Turns out that loading is always the slow part in loading initramfs into memory and decompressing it since decompression is always the final 10-20% or so of the task. It therefore makes sense to use a good compressor that shrinks the initramfs as much as possible with little decompression overhead. Benchmarking zstd vs lz4 shows that while zstd can be ~5x slower in decompression, the image size is much smaller with zstd than lz4, and since ~80-90% of the boot time is loading the image it makes sense to use zstd. Attached is a libreoffice spread sheet showing typical load and decompression times for a fairly standard 3.4 GHZ intel box with data for load times for a 5400 RPM, 7200 RPM and SATA SSD drives. The conclusions from the test results (attached) show: 1. Loading time is always significantly slower than decompression time. 2. ZSTD is 5x slower than LZ4 in decompression speed but produces far better compressed images 3. Given that loading time is the major factor in loading + decompression, ZSTD is best for kernel and initramfs boot timings. (Also refer to https://kernel.ubuntu.com/~cking/boot-speed- eoan-5.3/kernel-compression-method.txt for some raw data on drive load speeds for the same UEFI box I did a couple of years ago). amd64 supports zstd, but s390x does not. Will use this bug to enable zstd support on s390x. Upstream submitted patch https://lore.kernel.org/linux-s390/20210615114150.325080-1-dimitri.led...@canonical.com/T/#u To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-z-systems/+bug/1931725/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
[Touch-packages] [Bug 1931725] Re: initramfs-tools & kernel: use zstd as the default compression method
This bug was fixed in the package linux-oracle - 5.13.0-1008.10 --- linux-oracle (5.13.0-1008.10) impish; urgency=medium * impish/linux-oracle: 5.13.0-1008.10 -proposed tracker (LP: #1946331) * Miscellaneous Ubuntu changes - [Config] update toolchain version in configs after rebase [ Ubuntu: 5.13.0-19.19 ] * impish/linux: 5.13.0-19.19 -proposed tracker (LP: #1946337) * impish:linux-aws 5.13 panic during systemd autotest (LP: #1946001) - [Config] disable KFENCE [ Ubuntu: 5.13.0-18.18 ] * impish/linux: 5.13.0-18.18 -proposed tracker (LP: #1945995) * [21.10 FEAT] KVM: Use interpretation of specification exceptions (LP: #1932157) - KVM: s390: Enable specification exception interpretation -- Andrea Righi Fri, 08 Oct 2021 17:26:41 +0200 ** Changed in: linux-oracle (Ubuntu) Status: Fix Committed => Fix Released -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to initramfs-tools in Ubuntu. https://bugs.launchpad.net/bugs/1931725 Title: initramfs-tools & kernel: use zstd as the default compression method Status in Ubuntu on IBM z Systems: Fix Released Status in initramfs-tools package in Ubuntu: Fix Released Status in linux package in Ubuntu: Fix Released Status in linux-oracle package in Ubuntu: Fix Released Bug description: Turns out that loading is always the slow part in loading initramfs into memory and decompressing it since decompression is always the final 10-20% or so of the task. It therefore makes sense to use a good compressor that shrinks the initramfs as much as possible with little decompression overhead. Benchmarking zstd vs lz4 shows that while zstd can be ~5x slower in decompression, the image size is much smaller with zstd than lz4, and since ~80-90% of the boot time is loading the image it makes sense to use zstd. Attached is a libreoffice spread sheet showing typical load and decompression times for a fairly standard 3.4 GHZ intel box with data for load times for a 5400 RPM, 7200 RPM and SATA SSD drives. The conclusions from the test results (attached) show: 1. Loading time is always significantly slower than decompression time. 2. ZSTD is 5x slower than LZ4 in decompression speed but produces far better compressed images 3. Given that loading time is the major factor in loading + decompression, ZSTD is best for kernel and initramfs boot timings. (Also refer to https://kernel.ubuntu.com/~cking/boot-speed- eoan-5.3/kernel-compression-method.txt for some raw data on drive load speeds for the same UEFI box I did a couple of years ago). amd64 supports zstd, but s390x does not. Will use this bug to enable zstd support on s390x. Upstream submitted patch https://lore.kernel.org/linux-s390/20210615114150.325080-1-dimitri.led...@canonical.com/T/#u To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-z-systems/+bug/1931725/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
[Touch-packages] [Bug 1931725] Re: initramfs-tools & kernel: use zstd as the default compression method
** Also affects: linux-oracle (Ubuntu) Importance: Undecided Status: New ** Changed in: linux-oracle (Ubuntu) Status: New => Fix Committed -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to initramfs-tools in Ubuntu. https://bugs.launchpad.net/bugs/1931725 Title: initramfs-tools & kernel: use zstd as the default compression method Status in Ubuntu on IBM z Systems: Fix Released Status in initramfs-tools package in Ubuntu: Fix Released Status in linux package in Ubuntu: Fix Released Status in linux-oracle package in Ubuntu: Fix Committed Bug description: Turns out that loading is always the slow part in loading initramfs into memory and decompressing it since decompression is always the final 10-20% or so of the task. It therefore makes sense to use a good compressor that shrinks the initramfs as much as possible with little decompression overhead. Benchmarking zstd vs lz4 shows that while zstd can be ~5x slower in decompression, the image size is much smaller with zstd than lz4, and since ~80-90% of the boot time is loading the image it makes sense to use zstd. Attached is a libreoffice spread sheet showing typical load and decompression times for a fairly standard 3.4 GHZ intel box with data for load times for a 5400 RPM, 7200 RPM and SATA SSD drives. The conclusions from the test results (attached) show: 1. Loading time is always significantly slower than decompression time. 2. ZSTD is 5x slower than LZ4 in decompression speed but produces far better compressed images 3. Given that loading time is the major factor in loading + decompression, ZSTD is best for kernel and initramfs boot timings. (Also refer to https://kernel.ubuntu.com/~cking/boot-speed- eoan-5.3/kernel-compression-method.txt for some raw data on drive load speeds for the same UEFI box I did a couple of years ago). amd64 supports zstd, but s390x does not. Will use this bug to enable zstd support on s390x. Upstream submitted patch https://lore.kernel.org/linux-s390/20210615114150.325080-1-dimitri.led...@canonical.com/T/#u To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-z-systems/+bug/1931725/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
[Touch-packages] [Bug 1931725] Re: initramfs-tools & kernel: use zstd as the default compression method
This bug was fixed in the package linux - 5.13.0-14.14 --- linux (5.13.0-14.14) impish; urgency=medium * impish/linux: 5.13.0-14.14 -proposed tracker (LP: #1938565) * Miscellaneous Ubuntu changes - SAUCE: Revert "UBUNTU: SAUCE: random: Make getrandom() ready earlier" - SAUCE: random: properly make getrandom() ready earlier * Miscellaneous upstream changes - seq_buf: Fix overflow in seq_buf_putmem_hex() - bpf: Fix integer overflow in argument calculation for bpf_map_area_alloc - ext4: cleanup in-core orphan list if ext4_truncate() failed to get a transaction handle - ext4: fix kernel infoleak via ext4_extent_header - ext4: fix overflow in ext4_iomap_alloc() - ext4: return error code when ext4_fill_flex_info() fails - ext4: correct the cache_nr in tracepoint ext4_es_shrink_exit - ext4: remove check for zero nr_to_scan in ext4_es_scan() - ext4: fix avefreec in find_group_orlov - ext4: use ext4_grp_locked_error in mb_find_extent -- Andrea Righi Mon, 02 Aug 2021 14:23:08 +0200 ** Changed in: linux (Ubuntu) Status: Incomplete => Fix Released -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to initramfs-tools in Ubuntu. https://bugs.launchpad.net/bugs/1931725 Title: initramfs-tools & kernel: use zstd as the default compression method Status in Ubuntu on IBM z Systems: Fix Released Status in initramfs-tools package in Ubuntu: Fix Released Status in linux package in Ubuntu: Fix Released Bug description: Turns out that loading is always the slow part in loading initramfs into memory and decompressing it since decompression is always the final 10-20% or so of the task. It therefore makes sense to use a good compressor that shrinks the initramfs as much as possible with little decompression overhead. Benchmarking zstd vs lz4 shows that while zstd can be ~5x slower in decompression, the image size is much smaller with zstd than lz4, and since ~80-90% of the boot time is loading the image it makes sense to use zstd. Attached is a libreoffice spread sheet showing typical load and decompression times for a fairly standard 3.4 GHZ intel box with data for load times for a 5400 RPM, 7200 RPM and SATA SSD drives. The conclusions from the test results (attached) show: 1. Loading time is always significantly slower than decompression time. 2. ZSTD is 5x slower than LZ4 in decompression speed but produces far better compressed images 3. Given that loading time is the major factor in loading + decompression, ZSTD is best for kernel and initramfs boot timings. (Also refer to https://kernel.ubuntu.com/~cking/boot-speed- eoan-5.3/kernel-compression-method.txt for some raw data on drive load speeds for the same UEFI box I did a couple of years ago). amd64 supports zstd, but s390x does not. Will use this bug to enable zstd support on s390x. Upstream submitted patch https://lore.kernel.org/linux-s390/20210615114150.325080-1-dimitri.led...@canonical.com/T/#u To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-z-systems/+bug/1931725/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
[Touch-packages] [Bug 1931725] Re: initramfs-tools & kernel: use zstd as the default compression method
** Tags added: bot-stop-nagging ** Changed in: ubuntu-z-systems Status: New => Fix Released -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to initramfs-tools in Ubuntu. https://bugs.launchpad.net/bugs/1931725 Title: initramfs-tools & kernel: use zstd as the default compression method Status in Ubuntu on IBM z Systems: Fix Released Status in initramfs-tools package in Ubuntu: Fix Released Status in linux package in Ubuntu: Incomplete Bug description: Turns out that loading is always the slow part in loading initramfs into memory and decompressing it since decompression is always the final 10-20% or so of the task. It therefore makes sense to use a good compressor that shrinks the initramfs as much as possible with little decompression overhead. Benchmarking zstd vs lz4 shows that while zstd can be ~5x slower in decompression, the image size is much smaller with zstd than lz4, and since ~80-90% of the boot time is loading the image it makes sense to use zstd. Attached is a libreoffice spread sheet showing typical load and decompression times for a fairly standard 3.4 GHZ intel box with data for load times for a 5400 RPM, 7200 RPM and SATA SSD drives. The conclusions from the test results (attached) show: 1. Loading time is always significantly slower than decompression time. 2. ZSTD is 5x slower than LZ4 in decompression speed but produces far better compressed images 3. Given that loading time is the major factor in loading + decompression, ZSTD is best for kernel and initramfs boot timings. (Also refer to https://kernel.ubuntu.com/~cking/boot-speed- eoan-5.3/kernel-compression-method.txt for some raw data on drive load speeds for the same UEFI box I did a couple of years ago). amd64 supports zstd, but s390x does not. Will use this bug to enable zstd support on s390x. Upstream submitted patch https://lore.kernel.org/linux-s390/20210615114150.325080-1-dimitri.led...@canonical.com/T/#u To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-z-systems/+bug/1931725/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
[Touch-packages] [Bug 1931725] Re: initramfs-tools & kernel: use zstd as the default compression method
This bug is awaiting verification that the kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed- focal' to 'verification-done-focal'. If the problem still exists, change the tag 'verification-needed-focal' to 'verification-failed-focal'. If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you! ** Tags added: verification-needed-focal -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to initramfs-tools in Ubuntu. https://bugs.launchpad.net/bugs/1931725 Title: initramfs-tools & kernel: use zstd as the default compression method Status in Ubuntu on IBM z Systems: New Status in initramfs-tools package in Ubuntu: Fix Released Status in linux package in Ubuntu: New Bug description: Turns out that loading is always the slow part in loading initramfs into memory and decompressing it since decompression is always the final 10-20% or so of the task. It therefore makes sense to use a good compressor that shrinks the initramfs as much as possible with little decompression overhead. Benchmarking zstd vs lz4 shows that while zstd can be ~5x slower in decompression, the image size is much smaller with zstd than lz4, and since ~80-90% of the boot time is loading the image it makes sense to use zstd. Attached is a libreoffice spread sheet showing typical load and decompression times for a fairly standard 3.4 GHZ intel box with data for load times for a 5400 RPM, 7200 RPM and SATA SSD drives. The conclusions from the test results (attached) show: 1. Loading time is always significantly slower than decompression time. 2. ZSTD is 5x slower than LZ4 in decompression speed but produces far better compressed images 3. Given that loading time is the major factor in loading + decompression, ZSTD is best for kernel and initramfs boot timings. (Also refer to https://kernel.ubuntu.com/~cking/boot-speed-eoan-5.3 /kernel-compression-method.txt for some raw data on drive load speeds for the same UEFI box I did a couple of years ago). amd64 supports zstd, but s390x does not. Will use this bug to enable zstd support on s390x. Upstream submitted patch https://lore.kernel.org/linux-s390/20210615114150.325080-1-dimitri.led...@canonical.com/T/#u To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-z-systems/+bug/1931725/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
[Touch-packages] [Bug 1931725] Re: initramfs-tools & kernel: use zstd as the default compression method
@cborntra v5.13 ubuntu kernel's s390 configuration with zstd -22 --ultra compression is 8.5 MB, whereas gzip -9 is 11M. Thus for gzip to win at bootspeed the decompression speed has to compensate for 2.5M of i/o and be faster than zstd. Unaccelerated decompression comparison still gives me faster decompression with less i/o with zstd compressed kernel image. At Canonical we still do not have z15 mainframe available for us to benchmark this. -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to initramfs-tools in Ubuntu. https://bugs.launchpad.net/bugs/1931725 Title: initramfs-tools & kernel: use zstd as the default compression method Status in Ubuntu on IBM z Systems: New Status in initramfs-tools package in Ubuntu: Fix Released Status in linux package in Ubuntu: New Bug description: Turns out that loading is always the slow part in loading initramfs into memory and decompressing it since decompression is always the final 10-20% or so of the task. It therefore makes sense to use a good compressor that shrinks the initramfs as much as possible with little decompression overhead. Benchmarking zstd vs lz4 shows that while zstd can be ~5x slower in decompression, the image size is much smaller with zstd than lz4, and since ~80-90% of the boot time is loading the image it makes sense to use zstd. Attached is a libreoffice spread sheet showing typical load and decompression times for a fairly standard 3.4 GHZ intel box with data for load times for a 5400 RPM, 7200 RPM and SATA SSD drives. The conclusions from the test results (attached) show: 1. Loading time is always significantly slower than decompression time. 2. ZSTD is 5x slower than LZ4 in decompression speed but produces far better compressed images 3. Given that loading time is the major factor in loading + decompression, ZSTD is best for kernel and initramfs boot timings. (Also refer to https://kernel.ubuntu.com/~cking/boot-speed-eoan-5.3 /kernel-compression-method.txt for some raw data on drive load speeds for the same UEFI box I did a couple of years ago). amd64 supports zstd, but s390x does not. Will use this bug to enable zstd support on s390x. Upstream submitted patch https://lore.kernel.org/linux-s390/20210615114150.325080-1-dimitri.led...@canonical.com/T/#u To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-z-systems/+bug/1931725/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
[Touch-packages] [Bug 1931725] Re: initramfs-tools & kernel: use zstd as the default compression method
decompression speed only needs to be faster than i/o speed, once that is reached the best compression ratio results in the fastest bootspped. for kernel image zstd is used with -22 --ultra, thus I can compare it with zlib -9. -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to initramfs-tools in Ubuntu. https://bugs.launchpad.net/bugs/1931725 Title: initramfs-tools & kernel: use zstd as the default compression method Status in Ubuntu on IBM z Systems: New Status in initramfs-tools package in Ubuntu: Fix Released Status in linux package in Ubuntu: New Bug description: Turns out that loading is always the slow part in loading initramfs into memory and decompressing it since decompression is always the final 10-20% or so of the task. It therefore makes sense to use a good compressor that shrinks the initramfs as much as possible with little decompression overhead. Benchmarking zstd vs lz4 shows that while zstd can be ~5x slower in decompression, the image size is much smaller with zstd than lz4, and since ~80-90% of the boot time is loading the image it makes sense to use zstd. Attached is a libreoffice spread sheet showing typical load and decompression times for a fairly standard 3.4 GHZ intel box with data for load times for a 5400 RPM, 7200 RPM and SATA SSD drives. The conclusions from the test results (attached) show: 1. Loading time is always significantly slower than decompression time. 2. ZSTD is 5x slower than LZ4 in decompression speed but produces far better compressed images 3. Given that loading time is the major factor in loading + decompression, ZSTD is best for kernel and initramfs boot timings. (Also refer to https://kernel.ubuntu.com/~cking/boot-speed-eoan-5.3 /kernel-compression-method.txt for some raw data on drive load speeds for the same UEFI box I did a couple of years ago). amd64 supports zstd, but s390x does not. Will use this bug to enable zstd support on s390x. Upstream submitted patch https://lore.kernel.org/linux-s390/20210615114150.325080-1-dimitri.led...@canonical.com/T/#u To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-z-systems/+bug/1931725/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
[Touch-packages] [Bug 1931725] Re: initramfs-tools & kernel: use zstd as the default compression method
** Tags added: architecture-s39064 bugnameltc-193300 severity-high targetmilestone-inin2004 -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to initramfs-tools in Ubuntu. https://bugs.launchpad.net/bugs/1931725 Title: initramfs-tools & kernel: use zstd as the default compression method Status in Ubuntu on IBM z Systems: New Status in initramfs-tools package in Ubuntu: Fix Released Status in linux package in Ubuntu: New Bug description: Turns out that loading is always the slow part in loading initramfs into memory and decompressing it since decompression is always the final 10-20% or so of the task. It therefore makes sense to use a good compressor that shrinks the initramfs as much as possible with little decompression overhead. Benchmarking zstd vs lz4 shows that while zstd can be ~5x slower in decompression, the image size is much smaller with zstd than lz4, and since ~80-90% of the boot time is loading the image it makes sense to use zstd. Attached is a libreoffice spread sheet showing typical load and decompression times for a fairly standard 3.4 GHZ intel box with data for load times for a 5400 RPM, 7200 RPM and SATA SSD drives. The conclusions from the test results (attached) show: 1. Loading time is always significantly slower than decompression time. 2. ZSTD is 5x slower than LZ4 in decompression speed but produces far better compressed images 3. Given that loading time is the major factor in loading + decompression, ZSTD is best for kernel and initramfs boot timings. (Also refer to https://kernel.ubuntu.com/~cking/boot-speed-eoan-5.3 /kernel-compression-method.txt for some raw data on drive load speeds for the same UEFI box I did a couple of years ago). amd64 supports zstd, but s390x does not. Will use this bug to enable zstd support on s390x. Upstream submitted patch https://lore.kernel.org/linux-s390/20210615114150.325080-1-dimitri.led...@canonical.com/T/#u To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-z-systems/+bug/1931725/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
[Touch-packages] [Bug 1931725] Re: initramfs-tools & kernel: use zstd as the default compression method
Vasily Gorbik is reviewing this patch. -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to initramfs-tools in Ubuntu. https://bugs.launchpad.net/bugs/1931725 Title: initramfs-tools & kernel: use zstd as the default compression method Status in Ubuntu on IBM z Systems: New Status in initramfs-tools package in Ubuntu: Fix Released Status in linux package in Ubuntu: New Bug description: Turns out that loading is always the slow part in loading initramfs into memory and decompressing it since decompression is always the final 10-20% or so of the task. It therefore makes sense to use a good compressor that shrinks the initramfs as much as possible with little decompression overhead. Benchmarking zstd vs lz4 shows that while zstd can be ~5x slower in decompression, the image size is much smaller with zstd than lz4, and since ~80-90% of the boot time is loading the image it makes sense to use zstd. Attached is a libreoffice spread sheet showing typical load and decompression times for a fairly standard 3.4 GHZ intel box with data for load times for a 5400 RPM, 7200 RPM and SATA SSD drives. The conclusions from the test results (attached) show: 1. Loading time is always significantly slower than decompression time. 2. ZSTD is 5x slower than LZ4 in decompression speed but produces far better compressed images 3. Given that loading time is the major factor in loading + decompression, ZSTD is best for kernel and initramfs boot timings. (Also refer to https://kernel.ubuntu.com/~cking/boot-speed-eoan-5.3 /kernel-compression-method.txt for some raw data on drive load speeds for the same UEFI box I did a couple of years ago). amd64 supports zstd, but s390x does not. Will use this bug to enable zstd support on s390x. Upstream submitted patch https://lore.kernel.org/linux-s390/20210615114150.325080-1-dimitri.led...@canonical.com/T/#u To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-z-systems/+bug/1931725/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
[Touch-packages] [Bug 1931725] Re: initramfs-tools & kernel: use zstd as the default compression method
** Also affects: ubuntu-z-systems Importance: Undecided Status: New ** Changed in: ubuntu-z-systems Assignee: (unassigned) => bugproxy (bugproxy) ** Tags added: reverse-proxy-bugzilla s390x -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to initramfs-tools in Ubuntu. https://bugs.launchpad.net/bugs/1931725 Title: initramfs-tools & kernel: use zstd as the default compression method Status in Ubuntu on IBM z Systems: New Status in initramfs-tools package in Ubuntu: Fix Released Status in linux package in Ubuntu: New Bug description: Turns out that loading is always the slow part in loading initramfs into memory and decompressing it since decompression is always the final 10-20% or so of the task. It therefore makes sense to use a good compressor that shrinks the initramfs as much as possible with little decompression overhead. Benchmarking zstd vs lz4 shows that while zstd can be ~5x slower in decompression, the image size is much smaller with zstd than lz4, and since ~80-90% of the boot time is loading the image it makes sense to use zstd. Attached is a libreoffice spread sheet showing typical load and decompression times for a fairly standard 3.4 GHZ intel box with data for load times for a 5400 RPM, 7200 RPM and SATA SSD drives. The conclusions from the test results (attached) show: 1. Loading time is always significantly slower than decompression time. 2. ZSTD is 5x slower than LZ4 in decompression speed but produces far better compressed images 3. Given that loading time is the major factor in loading + decompression, ZSTD is best for kernel and initramfs boot timings. (Also refer to https://kernel.ubuntu.com/~cking/boot-speed-eoan-5.3 /kernel-compression-method.txt for some raw data on drive load speeds for the same UEFI box I did a couple of years ago). amd64 supports zstd, but s390x does not. Will use this bug to enable zstd support on s390x. Upstream submitted patch https://lore.kernel.org/linux-s390/20210615114150.325080-1-dimitri.led...@canonical.com/T/#u To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-z-systems/+bug/1931725/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
[Touch-packages] [Bug 1931725] Re: initramfs-tools & kernel: use zstd as the default compression method
@ IBM can you please review the upstream patch and merge it into the the s390 tree ? https://lore.kernel.org/linux-s390/20210615114150.325080-1-dimitri.led...@canonical.com/T/#u ** Description changed: Turns out that loading is always the slow part in loading initramfs into memory and decompressing it since decompression is always the final 10-20% or so of the task. It therefore makes sense to use a good compressor that shrinks the initramfs as much as possible with little decompression overhead. Benchmarking zstd vs lz4 shows that while zstd can be ~5x slower in decompression, the image size is much smaller with zstd than lz4, and since ~80-90% of the boot time is loading the image it makes sense to use zstd. Attached is a libreoffice spread sheet showing typical load and decompression times for a fairly standard 3.4 GHZ intel box with data for load times for a 5400 RPM, 7200 RPM and SATA SSD drives. The conclusions from the test results (attached) show: 1. Loading time is always significantly slower than decompression time. 2. ZSTD is 5x slower than LZ4 in decompression speed but produces far better compressed images 3. Given that loading time is the major factor in loading + decompression, ZSTD is best for kernel and initramfs boot timings. (Also refer to https://kernel.ubuntu.com/~cking/boot-speed-eoan-5.3 /kernel-compression-method.txt for some raw data on drive load speeds for the same UEFI box I did a couple of years ago). amd64 supports zstd, but s390x does not. Will use this bug to enable zstd support on s390x. + + Upstream submitted patch + https://lore.kernel.org/linux-s390/20210615114150.325080-1-dimitri.led...@canonical.com/T/#u -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to initramfs-tools in Ubuntu. https://bugs.launchpad.net/bugs/1931725 Title: initramfs-tools & kernel: use zstd as the default compression method Status in initramfs-tools package in Ubuntu: Fix Released Status in linux package in Ubuntu: New Bug description: Turns out that loading is always the slow part in loading initramfs into memory and decompressing it since decompression is always the final 10-20% or so of the task. It therefore makes sense to use a good compressor that shrinks the initramfs as much as possible with little decompression overhead. Benchmarking zstd vs lz4 shows that while zstd can be ~5x slower in decompression, the image size is much smaller with zstd than lz4, and since ~80-90% of the boot time is loading the image it makes sense to use zstd. Attached is a libreoffice spread sheet showing typical load and decompression times for a fairly standard 3.4 GHZ intel box with data for load times for a 5400 RPM, 7200 RPM and SATA SSD drives. The conclusions from the test results (attached) show: 1. Loading time is always significantly slower than decompression time. 2. ZSTD is 5x slower than LZ4 in decompression speed but produces far better compressed images 3. Given that loading time is the major factor in loading + decompression, ZSTD is best for kernel and initramfs boot timings. (Also refer to https://kernel.ubuntu.com/~cking/boot-speed-eoan-5.3 /kernel-compression-method.txt for some raw data on drive load speeds for the same UEFI box I did a couple of years ago). amd64 supports zstd, but s390x does not. Will use this bug to enable zstd support on s390x. Upstream submitted patch https://lore.kernel.org/linux-s390/20210615114150.325080-1-dimitri.led...@canonical.com/T/#u To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/initramfs-tools/+bug/1931725/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
[Touch-packages] [Bug 1931725] Re: initramfs-tools & kernel: use zstd as the default compression method
** Summary changed: - initramfs-tools: use zstd as the default compression method + initramfs-tools & kernel: use zstd as the default compression method ** Description changed: Turns out that loading is always the slow part in loading initramfs into memory and decompressing it since decompression is always the final 10-20% or so of the task. It therefore makes sense to use a good compressor that shrinks the initramfs as much as possible with little decompression overhead. Benchmarking zstd vs lz4 shows that while zstd can be ~5x slower in decompression, the image size is much smaller with zstd than lz4, and since ~80-90% of the boot time is loading the image it makes sense to use zstd. Attached is a libreoffice spread sheet showing typical load and decompression times for a fairly standard 3.4 GHZ intel box with data for load times for a 5400 RPM, 7200 RPM and SATA SSD drives. The conclusions from the test results (attached) show: 1. Loading time is always significantly slower than decompression time. 2. ZSTD is 5x slower than LZ4 in decompression speed but produces far better compressed images 3. Given that loading time is the major factor in loading + decompression, ZSTD is best for kernel and initramfs boot timings. (Also refer to https://kernel.ubuntu.com/~cking/boot-speed-eoan-5.3 /kernel-compression-method.txt for some raw data on drive load speeds for the same UEFI box I did a couple of years ago). + + amd64 supports zstd, but s390x does not. Will use this bug to enable + zstd support on s390x. -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to initramfs-tools in Ubuntu. https://bugs.launchpad.net/bugs/1931725 Title: initramfs-tools & kernel: use zstd as the default compression method Status in initramfs-tools package in Ubuntu: Fix Released Status in linux package in Ubuntu: New Bug description: Turns out that loading is always the slow part in loading initramfs into memory and decompressing it since decompression is always the final 10-20% or so of the task. It therefore makes sense to use a good compressor that shrinks the initramfs as much as possible with little decompression overhead. Benchmarking zstd vs lz4 shows that while zstd can be ~5x slower in decompression, the image size is much smaller with zstd than lz4, and since ~80-90% of the boot time is loading the image it makes sense to use zstd. Attached is a libreoffice spread sheet showing typical load and decompression times for a fairly standard 3.4 GHZ intel box with data for load times for a 5400 RPM, 7200 RPM and SATA SSD drives. The conclusions from the test results (attached) show: 1. Loading time is always significantly slower than decompression time. 2. ZSTD is 5x slower than LZ4 in decompression speed but produces far better compressed images 3. Given that loading time is the major factor in loading + decompression, ZSTD is best for kernel and initramfs boot timings. (Also refer to https://kernel.ubuntu.com/~cking/boot-speed-eoan-5.3 /kernel-compression-method.txt for some raw data on drive load speeds for the same UEFI box I did a couple of years ago). amd64 supports zstd, but s390x does not. Will use this bug to enable zstd support on s390x. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/initramfs-tools/+bug/1931725/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
