2019-06-05 12:21:48 |
Dimitri John Ledkov |
bug |
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added bug |
2019-06-05 12:21:55 |
Dimitri John Ledkov |
bug task added |
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livecd-rootfs (Ubuntu) |
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2019-06-05 12:22:12 |
Dimitri John Ledkov |
bug task added |
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live-build (Ubuntu) |
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2019-06-05 12:22:25 |
Dimitri John Ledkov |
bug task added |
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linux (Ubuntu) |
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2019-06-05 12:22:48 |
Dimitri John Ledkov |
summary |
lz4 by default |
[MIR] lz4 by default |
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2019-06-05 12:22:52 |
Dimitri John Ledkov |
bug task added |
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lz4 (Ubuntu) |
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2019-06-05 12:23:09 |
Dimitri John Ledkov |
description |
Use `lz4 -9 -l` compression for initramfs by default as discussed on ubuntu-devel.
https://lists.ubuntu.com/archives/ubuntu-devel/2019-June/040726.html |
Use `lz4 -9 -l` compression for initramfs by default as discussed on ubuntu-devel.
This would also pull the lz4 package into main
https://lists.ubuntu.com/archives/ubuntu-devel/2019-June/040726.html |
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2019-06-05 12:30:06 |
Ubuntu Kernel Bot |
linux (Ubuntu): status |
New |
Incomplete |
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2019-06-05 12:38:49 |
Dimitri John Ledkov |
lz4 (Ubuntu): status |
New |
Confirmed |
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2019-06-05 12:38:57 |
Dimitri John Ledkov |
initramfs-tools (Ubuntu): status |
New |
Fix Committed |
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2019-06-05 12:39:00 |
Dimitri John Ledkov |
live-build (Ubuntu): status |
New |
Fix Committed |
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2019-06-05 12:59:08 |
Dimitri John Ledkov |
livecd-rootfs (Ubuntu): status |
New |
Fix Committed |
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2019-06-05 15:27:14 |
Launchpad Janitor |
live-build (Ubuntu): status |
Fix Committed |
Fix Released |
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2019-06-05 16:21:50 |
Launchpad Janitor |
livecd-rootfs (Ubuntu): status |
Fix Committed |
Fix Released |
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2019-06-05 19:16:46 |
Steve Langasek |
bug task added |
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ubuntu-release-upgrader (Ubuntu) |
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2019-06-05 19:16:59 |
Steve Langasek |
ubuntu-release-upgrader (Ubuntu): assignee |
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Dimitri John Ledkov (xnox) |
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2019-06-05 19:17:04 |
Steve Langasek |
ubuntu-release-upgrader (Ubuntu): status |
New |
Triaged |
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2019-06-05 19:17:05 |
Steve Langasek |
ubuntu-release-upgrader (Ubuntu): importance |
Undecided |
High |
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2019-06-05 19:17:19 |
Steve Langasek |
bug task added |
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partman-auto (Ubuntu) |
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2019-06-05 19:17:27 |
Steve Langasek |
partman-auto (Ubuntu): status |
New |
Triaged |
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2019-06-05 19:17:28 |
Steve Langasek |
partman-auto (Ubuntu): importance |
Undecided |
High |
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2019-06-05 19:17:34 |
Steve Langasek |
partman-auto (Ubuntu): assignee |
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Dimitri John Ledkov (xnox) |
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2019-06-06 07:53:45 |
Launchpad Janitor |
initramfs-tools (Ubuntu): status |
Fix Committed |
Fix Released |
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2019-06-07 11:38:22 |
Dimitri John Ledkov |
lz4 (Ubuntu): status |
Confirmed |
Fix Released |
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2019-06-07 11:38:28 |
Dimitri John Ledkov |
linux (Ubuntu): status |
Incomplete |
Confirmed |
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2019-06-07 11:46:42 |
Dimitri John Ledkov |
description |
Use `lz4 -9 -l` compression for initramfs by default as discussed on ubuntu-devel.
This would also pull the lz4 package into main
https://lists.ubuntu.com/archives/ubuntu-devel/2019-June/040726.html |
Use `lz4 -9 -l` compression for initramfs by default as discussed on ubuntu-devel.
This would also pull the lz4 package into main
https://lists.ubuntu.com/archives/ubuntu-devel/2019-June/040726.html
[Regression Potential]
We are trying to optimize for total boot speed, but performing a micro-optimization upon time to create/unpack kernel/initrd is an insufficient benchmark for total boot speed. This is because it ignores time to load the kernel/initrd, and whether the firmware/bootloader were able to stream decompress it whilst loading it. I.e. it is argued that in the real world, subsecond decompression gains are irrelevant if UEFI firmware, tftp boot, etc. take a lot longer than that to read extra 10s of MBs of boot material.
[TODO]
Measure pure i/o load speed with stopwatch, to figure out MB/s speed of loading initrds/kernel off FAT32, EXT4, TFTP, HTTP.
Re-evaluate if we should provide different compression mechanisms:
- ie. gzip instead of lz4 for most cases (revert)
- ie. xz for painful i/o cases (e.g. netboot) |
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2019-06-07 13:00:03 |
Dimitri John Ledkov |
description |
Use `lz4 -9 -l` compression for initramfs by default as discussed on ubuntu-devel.
This would also pull the lz4 package into main
https://lists.ubuntu.com/archives/ubuntu-devel/2019-June/040726.html
[Regression Potential]
We are trying to optimize for total boot speed, but performing a micro-optimization upon time to create/unpack kernel/initrd is an insufficient benchmark for total boot speed. This is because it ignores time to load the kernel/initrd, and whether the firmware/bootloader were able to stream decompress it whilst loading it. I.e. it is argued that in the real world, subsecond decompression gains are irrelevant if UEFI firmware, tftp boot, etc. take a lot longer than that to read extra 10s of MBs of boot material.
[TODO]
Measure pure i/o load speed with stopwatch, to figure out MB/s speed of loading initrds/kernel off FAT32, EXT4, TFTP, HTTP.
Re-evaluate if we should provide different compression mechanisms:
- ie. gzip instead of lz4 for most cases (revert)
- ie. xz for painful i/o cases (e.g. netboot) |
Use `lz4 -9 -l` compression for initramfs by default as discussed on ubuntu-devel.
This would also pull the lz4 package into main
https://lists.ubuntu.com/archives/ubuntu-devel/2019-June/040726.html
[Regression Potential]
We are trying to optimize for total boot speed, but performing a micro-optimization upon time to create/unpack kernel/initrd is an insufficient benchmark for total boot speed. This is because it ignores time to load the kernel/initrd, and whether the firmware/bootloader were able to stream decompress it whilst loading it. I.e. it is argued that in the real world, subsecond decompression gains are irrelevant if UEFI firmware, tftp boot, etc. take a lot longer than that to read extra 10s of MBs of boot material.
[TODO]
Measure pure i/o load speed with stopwatch, to figure out MB/s speed of loading initrds/kernel off FAT32, EXT4, TFTP, HTTP.
Re-evaluate if we should provide different compression mechanisms:
- ie. gzip instead of lz4 for most cases (revert)
- ie. xz for painful i/o cases (e.g. netboot)
I booted grub2 and measured loading largish amount of files, ie. $ date; initrd (hd0,gpt5)/initrd.img; initrd (hd0,gpt5)/initrd.img; initrd (hd0,gpt5)/initrd.img; initrd (hd0,gpt5)/initrd.img; initrd (hd0,gpt5)/initrd.img; date
To get a rough speed between 30 and 44 MB/s of loading these files off ext4 on nvme.
With lz4 initrd taking 67M, and gzip initrd taking 59M, the grub i/o penalty is 0.18s whilst I gain over a second in faster decompression time. Overall a win.
xz initrd is 36M meaning saving e.g. 0.8s of i/o time whilst gaining 2.4s of decompression time, meaning overall worse than gzip. |
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2019-06-12 19:20:12 |
Brian Murray |
bug |
|
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added subscriber Brian Murray |
2019-06-13 12:25:38 |
Francis Ginther |
tags |
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id-5d0162d5caee4b55443d4eda |
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2019-10-15 08:59:28 |
Dimitri John Ledkov |
linux (Ubuntu): status |
Confirmed |
Fix Released |
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2019-10-15 09:18:01 |
Dimitri John Ledkov |
partman-auto (Ubuntu): status |
Triaged |
Invalid |
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2019-10-15 09:18:05 |
Dimitri John Ledkov |
ubuntu-release-upgrader (Ubuntu): status |
Triaged |
Invalid |
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2019-10-15 09:36:23 |
Dimitri John Ledkov |
bug task added |
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ubuntu-release-upgrader |
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2019-10-15 09:36:09 |
Launchpad Janitor |
branch linked |
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lp:~xnox/ubuntu-release-upgrader/eoan-kernel-sizes |
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2019-10-17 06:07:39 |
Mathew Hodson |
bug |
|
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added subscriber Mathew Hodson |
2020-01-12 21:12:55 |
Mathew Hodson |
bug task deleted |
partman-auto (Ubuntu) |
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2020-01-12 21:13:02 |
Mathew Hodson |
initramfs-tools (Ubuntu): importance |
Undecided |
High |
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2020-01-12 21:13:05 |
Mathew Hodson |
linux (Ubuntu): importance |
Undecided |
High |
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2020-01-12 21:13:06 |
Mathew Hodson |
live-build (Ubuntu): importance |
Undecided |
High |
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2020-01-12 21:13:09 |
Mathew Hodson |
livecd-rootfs (Ubuntu): importance |
Undecided |
High |
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2020-01-12 21:13:12 |
Mathew Hodson |
lz4 (Ubuntu): importance |
Undecided |
High |
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2020-02-24 08:53:27 |
Launchpad Janitor |
merge proposal linked |
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https://code.launchpad.net/~lihow731/ubuntu/+source/live-build/+git/live-build/+merge/379717 |
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2020-04-10 03:15:38 |
Mathew Hodson |
removed subscriber Mathew Hodson |
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2020-04-10 03:15:51 |
Mathew Hodson |
bug task deleted |
ubuntu-release-upgrader (Ubuntu) |
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2020-04-10 03:17:43 |
Mathew Hodson |
bug task deleted |
linux (Ubuntu) |
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2020-04-10 03:23:28 |
Mathew Hodson |
bug task added |
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ubuntu-release-upgrader (Ubuntu) |
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2020-04-10 03:23:37 |
Mathew Hodson |
ubuntu-release-upgrader (Ubuntu): status |
New |
Won't Fix |
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2020-04-10 03:23:40 |
Mathew Hodson |
ubuntu-release-upgrader (Ubuntu): importance |
Undecided |
High |
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2020-04-10 03:27:54 |
Mathew Hodson |
bug |
|
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added subscriber Mathew Hodson |