RFE: iotop should be smart enough to enable task_delayacct if needed

[Mikko Rantalainen]

Since commit https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e4042ad492357fa995921376462b04a025dd53b6 linux kernel has defaulted to disabling task delay accounting because it causes some runtime overhead.

Since iotop already requires root access and it wants to see delay accounting information, it should automatically enable delay accounting when run and possibly restore the previous state on exit.

In practice, iotop should write 1 to /proc/sys/kernel/task_delayacct instead of complaining

    CONFIG_TASK_DELAY_ACCT not enabled in kernel, cannot determine SWAPIN and IO %

and maybe write 0 before exit if that modification was needed during startup.

ProblemType: Bug
DistroRelease: Ubuntu 22.04
Package: iotop 0.6-24-g733f3f8-1.1ubuntu0.1
ProcVersionSignature: Ubuntu 6.2.0-1016.16~22.04.1-lowlatency 6.2.16
Uname: Linux 6.2.0-1016-lowlatency x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.11-0ubuntu82.5
Architecture: amd64
CasperMD5CheckResult: unknown
CurrentDesktop: XFCE
Date: Mon Dec 4 14:36:14 2023
Dependencies:

EcryptfsInUse: Yes
InstallationDate: Installed on 2019-01-05 (1793 days ago)
InstallationMedia: Ubuntu 18.04.1 LTS "Bionic Beaver" - Release amd64 (20180725)
RebootRequiredPkgs: Error: path contained symlinks.
SourcePackage: iotop
UpgradeStatus: Upgraded to jammy on 2023-08-11 (115 days ago)
modified.conffile..etc.init.d.apport: [modified]
mtime.conffile..etc.init.d.apport: 2022-05-19T12:50:20.029158

[Lucas Kanashiro (lucaskanashiro)]

Hi Mikko,

Thanks for taking the time to report this bug and trying to make Ubuntu better.

There is this other LP bug about this issue:

https://bugs.launchpad.net/ubuntu/+source/iotop/+bug/1982727

It was marked as Won't Fix in Jammy here:

https://bugs.launchpad.net/ubuntu/+source/iotop/+bug/1982727/comments/18

According to the next comment there you can find some info in the Ubuntu Jammy (22.04) release notes.

I am marking this bug as a duplicate.