bugGNU GRUB - Bugs: bug #65265, 100% of a core used while waiting...

 
 

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bug #65265: 100% of a core used while waiting for luks decription password in KVM

Submitter:  Tim <elatllat>
Submitted:  Tue 06 Feb 2024 05:46:41 PM UTC
Votes: 1
 
Category:  Filesystem Severity:  Major
Priority:  5 - Normal Item Group:  Software Error
Status:  None Privacy:  Public
Assigned to:  None Originator Name: 
Open/Closed:  Open Release:  Git master
Release:  Reproducibility:  Every Time
Planned Release:  None

Sat 17 Aug 2024 11:36:18 AM UTC, comment #3: 

Although I have not explicitly stated this:

I'm running grub/debian bare metal.

This appears to be unrelated to KVM or any other virtual platform afaict.

 John Kirk <bigsmile>
Mon 12 Aug 2024 06:42:10 AM UTC, comment #2: 

https://lists.gnu.org/archive/html/bug-grub/2019-07/msg00005.html

--
On Wed, Jun 26, 2019 at 8:10 PM James Harvey <address@hidden> wrote:

Found what's causing the 100% CPU usage.  12 years ago, 0149ab7c6 disabled the 'hlt' instruction in include/grub/i386/time.h::grub_cpu_idle(), noting "this can't work until we handle interrupts."  This later made its way into include/grub/x86_64/time.h as well.
--

Can someone confirm if this is related ?

 John Kirk <bigsmile>
Sun 11 Aug 2024 08:33:57 AM UTC, comment #1: 

I am a Debian 12 (released on June 10th, 2023) user running into the same issue. (currently at 12.6)

During installation I opted for "full disk encryption" which includes /boot. My situation is more cumbersome as I use a passively cooled computer without any fans. Besides draining my energy bill the computer gets HOT! I've measured 160°F/71°C on the chassis (a big cooling block) which is still within spec, but very undesirable over longer periods of time.

A desirable solution would be to idle and then suspend or power off after no input for a given period.

My problem comes from: /boot/efi/EFI/Debian/grubx64.efi
--
Welcome to GRUB!

Attempting to decrypt master key...
Enter passphrase for <disk>,<partition> (UUID string):
--

Packages installed:
--
ii  grub-common                            2.06-13+deb12u1                      amd64        GRand Unified Bootloader (common files)
ii  grub-efi-amd64                         2.06-13+deb12u1                      amd64        GRand Unified Bootloader, version 2 (EFI-AMD64 version)
ii  grub-efi-amd64-bin                     2.06-13+deb12u1                      amd64        GRand Unified Bootloader, version 2 (EFI-AMD64 modules)
ii  grub-efi-amd64-signed                  1+2.06+13+deb12u1                    amd64        GRand Unified Bootloader, version 2 (amd64 UEFI signed by Debian)
ii  grub2-common                           2.06-13+deb12u1                      amd64        GRand Unified Bootloader (common files for version 2)
--

Apparently this problem was hinted at in:
https://lists.gnu.org/archive/html/help-grub/2022-11/msg00025.html

 John Kirk <bigsmile>
Tue 06 Feb 2024 05:46:41 PM UTC, original submission:  

1) Install an OS with an encrypted boot option in KVM. eg: EndeavourOS with grub 2.12​, SpiralLinux with grub 2.06
2) Install an OS with a non-encrypted boot option in KVM. eg: Arch, Debian, Fedora
3) boot the VMs, do not enter a password, and note how a core is running at 100% only for the VMs still in grub / with encrypted boot.

 Tim <elatllat>

 

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