Just upgraded a machine to noble (24.04) and found out, that dracut-
install is slow as hell. A "update-initramfs -c -k all" takes ~ 45s to
create a /boot/initrd.img-6.8.0-60-generic of ~16 MB (removed all other
kernels for testing). 4x longer than expected!!! If I comment out the
"/usr/lib/dracut/dracut-install ..." call in /usr/share/initramfs-
tools/hook-functions:_call_dracut_install(), it takes ~10s, only.
_call_dracut_install() gets called 15x, so /usr/lib/dracut/dracut-
install is probably the cause. On test the box was idle and uses 2x AMD
EPYC 9254 2.90 GHz 24-Core Processor with a NVMe SSD as root/boot disk
(SAMSUNG MZQL2960HCJR-00A07) and 1.5 TB RAM, all disks have > 500 GB
space available, so sufficient resources to get the job done pretty
fast. Not sure, why it behaves so bad, but calling about 62K readlink()
whereby ~50k of them return "-1 EINVAL" because the argument is a
directory might be a hint. E.g. 6203 fails for 'readlink("/sys",
0x7fffc447c2e0, 1023)', same for "/sys/devices" and
"/sys/devices/platform" as well as 6168 fails for "/sys/bus" and
"/sys/bus/platform" - so at least half of those calls seem to be total
overhead ... Not sure, whether this is the root cause for its terrible
slowness but fixing it would probably not hurt ;-)
--
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/2081334
Title:
further performance improvement for dracut-install 060
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/initramfs-tools/+bug/2081334/+subscriptions
--
ubuntu-bugs mailing list
[email protected]
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
