Comment 0 for bug 1626436

With yakkety's recent update from linux 4.4 to 4.8 booting has become a lot slower. It's not one service in particular, but without "quiet" and "splash" you can now easily read every single line instead of that whole wall of text zipping by. It now takes over 20s instead of ~10 seconds to boot.

This is even more dramatic when factoring out the recent boot hang of NetworkManager (bug 1622893) and disabling lightdm:

  sudo systemctl mask NetworkManager NetworkManager-wait-online lightdm

then booting with 4.4 takes 1.5s and with 4.8 19.5s (!).

Some excerps from systemd-analyze blame:

4.4:
           474ms postfix@-.service
           395ms lxd-containers.service
           305ms networking.service

4.8:
          4.578s postfix@-.service
          7.300s lxd-containers.service
          6.285s networking.service

I attach the full outputs of critical-chain and analyze for 4.4 and 4.8 for reference.

This is much less noticeable in the running system. There is no immediate feeling of sluggishness (although my system is by and large idle).

I compared the time of sbuilding colord under similar circumstances (-j4, building on tmpfs, thus no hard disk delays; running with fully pre-loaded apt-cacher-ng thus no random network delays), and with 4.4 it takes 6.5 minutes and with 4.8 it takes 7.5. So that got a bit slower, but much less dramatically than during boot, so this is either happening when a lot of processes run in parallel, or is perhaps related to setting up cgroups.

One thing I noticed that during sbuild in 4.8 "top" shows ridiculous loads (~ 250) under 4.8, while it's around 4 or 5 under 4.8. But that doesn't reflect in actual sluggishness, so this might be just an unrelated bug.

ProblemType: Bug
DistroRelease: Ubuntu 16.10
Package: linux-image-4.8.0-11-generic 4.8.0-11.12
ProcVersionSignature: Ubuntu 4.8.0-11.12-generic 4.8.0-rc6
Uname: Linux 4.8.0-11-generic x86_64
ApportVersion: 2.20.3-0ubuntu7
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/pcmC0D0c: martin 3049 F...m pulseaudio
 /dev/snd/pcmC0D0p: martin 3049 F...m pulseaudio
 /dev/snd/controlC0: martin 3049 F.... pulseaudio
Date: Thu Sep 22 09:42:56 2016
EcryptfsInUse: Yes
MachineType: LENOVO 2324CTO
ProcEnviron:
 TERM=linux
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/@/boot/vmlinuz-4.8.0-11-generic.efi.signed root=UUID=f86539b0-3a1b-4372-83b0-acdd029ade68 ro rootflags=subvol=@ systemd.debug-shell
RelatedPackageVersions:
 linux-restricted-modules-4.8.0-11-generic N/A
 linux-backports-modules-4.8.0-11-generic N/A
 linux-firmware 1.161
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 07/09/2013
dmi.bios.vendor: LENOVO
dmi.bios.version: G2ET95WW (2.55 )
dmi.board.asset.tag: Not Available
dmi.board.name: 2324CTO
dmi.board.vendor: LENOVO
dmi.board.version: 0B98401 Pro
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Not Available
dmi.modalias: dmi:bvnLENOVO:bvrG2ET95WW(2.55):bd07/09/2013:svnLENOVO:pn2324CTO:pvrThinkPadX230:rvnLENOVO:rn2324CTO:rvr0B98401Pro:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.name: 2324CTO
dmi.product.version: ThinkPad X230
dmi.sys.vendor: LENOVO