A situation for which the currently configured kernel is poor is the
following:

- a single-user desktop machine
- runs a scripted daily backup using, eg, tar and bz2 compression.

The backup script needs to run as root, to access files system wide.
Because of the compression stage, the backup script is CPU intensive.
The user's script runs with a large "nice" value. In the present
configuration, although the user's desktop remains responsive while the
backup runs, the backup process running as root takes a significant
share of the CPU time, and affects any CPU-intensive task the user is
running. If the kernel is recompiled with CONFIG_FAIR_CGROUP_SCHED, then
the "nice" value has the desired effect and the backup script is
unobstrusive.

I have verified this using hardy's 2.6.24-10-generic. Recompiling with
CONFIG_FAIR_CGROUP_SCHED greatly increased the CPU share that the user's
processes were given while the backup was running.

Anyway, the point of this post is to point out that things like boinc
are far from the only cases where the present config has a downside. And
unlike the boinc case, a systemwide backup cannot so easily be run as
another user.

-- 
Kernel should use CONFIG_FAIR_CGROUP_SCHED
https://bugs.launchpad.net/bugs/188226
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.

-- 
ubuntu-bugs mailing list
[email protected]
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs

Reply via email to