#904393 qemu-kvm: CLOCK_MONOTONIC jumps during suspend of the host Linux

Package:
qemu-kvm
Source:
qemu
Submitter:
Ryutaroh Matsumoto
Date:
2025-07-28 19:57:08 UTC
Severity:
normal
#904393#5
Date:
2018-07-23 23:26:33 UTC
From:
To:
Dear Maintainer,

CLOCK_MONOTONIC should not jump during sleep, according to the systemd developer
https://github.com/systemd/systemd/issues/9538#issuecomment-405901335

When the host Linux is supended by "systemctl suspend",
CLOCK_MONOTONIC of the host does not include the time during suspend
and does not jump, but CLOCK_MONOTONIC in the linux running on qemu-kvm
jumps, as follows:

root@debian-unstable:/var/tmp# while true; do python3 -c "import time; print(time.monotonic())"; sleep 100; done
19938.840492947
20038.868252082
20138.894991601
20238.91993227
20338.948723988
20995.602910365

This leads to loss of systemd-journald logs as described in
https://github.com/systemd/systemd/issues/9538
#904393#10
Date:
2018-07-24 13:44:08 UTC
From:
To:
24.07.2018 02:26, Ryutaroh Matsumoto пишет:

It is best to address this upstream. Due to too specific of an issue I highly
doubt I'll be able to act on this bugreport in any sensible way, even checking
if the bug is still present after new qemu version is problematic.

Thanks,

/mjt