Arch Linux

nierro

Member

From: Milan, Italy

Registered: 2011-09-02

Posts: 849

Kernel takes too much time to load, according to systemd-analyze

Hi!
So, i have a lenovo laptop with a ssd, and a asus eeepc with a slow hdd. Obviously the laptop takes less time to bootup, but its kernel time is far higher:

LAPTOP
systemd-analyze
Startup finished in 3.365s (kernel) + 1.249s (initrd) + 334ms (userspace) = 4.949s

du -h /boot/initramfs-linux.img
13M     /boot/initramfs-linux.img
du -h /boot/vmlinuz-linux
3,9M    /boot/vmlinuz-linux

NETBOOK
Startup finished in 354ms (kernel) + 4.083s (initrd) + 7.012s (userspace) = 11.450s

du -h /boot/initramfs-linux.img
13M     /boot/initramfs-linux.img
du -h /boot/vmlinuz-linux
3,9M    /boot/vmlinuz-linux

mkinitcpio.conf looks the same on both machine:

# vim:set ft=sh
# MODULES
MODULES="i915 ext4 ahci sd_mod"

# BINARIES
BINARIES=""

# FILES
FILES=""

# HOOKS
HOOKS="systemd"

# COMPRESSION
COMPRESSION="cat"

So the difference in initrd seems legit (the first in fact is on a ssd, and it takes 1/4 than on netbook's hdd).
But why kernel time is 10x slower on my laptop? Any clue about where to look? The kernel is stock arch on both.

Thanks!

EDIT: tried this on 2 other laptops in my house, and results are: my brother's laptop with a ssd: 661ms (kernel), my father's laptop, with hdd: 410ms (kernel).
I really don't have a clue about where the issue can be...hoping for a hint

Last edited by nierro (2014-10-30 17:48:00)

nierro

Member

From: Milan, Italy

Registered: 2011-09-02

Posts: 849

Re: Kernel takes too much time to load, according to systemd-analyze

Ok, it seems i found, through dmesg, where i waste all that time:

[    0.576654] pci 0000:00:02.0: Video device with shadowed ROM
[    1.910484] pci 0000:00:1a.0: EHCI: BIOS handoff failed (BIOS bug?) 01010001
[    3.245211] pci 0000:00:1d.0: EHCI: BIOS handoff failed (BIOS bug?) 01010001
[    3.245396] pci 0000:01:00.0: set MSI_INTX_DISABLE_BUG flag

And there is a bug report open: https://bugs.launchpad.net/ubuntu/+sour … ug/1299104. It seems a bios problem.

EDIT: it seems the only solution is to change wait value from 5s to something lower in drivers/usb/host/pci-quirks.c.

Last edited by nierro (2014-10-30 19:49:32)