[systemd-devel] [PATCH] core: add startup resource control option

[Umut Tezduyar Lindskog]

On Thu, May 22, 2014 at 9:07 AM, Lennart Poettering
<lennart at poettering.net> wrote:
> On Thu, 22.05.14 08:42, Umut Tezduyar Lindskog (umut at tezduyar.com) wrote:
>
>>
>> On Thu, May 22, 2014 at 2:18 AM, Lennart Poettering
>> <lennart at poettering.net> wrote:
>> > On Wed, 21.05.14 14:02, Umut Tezduyar Lindskog (umut at tezduyar.com) wrote:
>> >
>> >>
>> >> Hi Cho,
>> >>
>> >> Do you have any technical reason why CPU shares are reverted back to
>> >> the default value on "StartupFinished" but instead when the unit is in
>> >> "activated" state?
>> >
>> > Well, the startup is only considered finished when the default target is
>> > reached, which usually means that all units the target pulled in are
>> > actually in activated state.
>>
>> I believe you haven't had time to look at the rest of the thread. I
>> tried to explain it a bit more here:
>> http://lists.freedesktop.org/archives/systemd-devel/2014-May/019377.html
>
> I did. But again, the StartupFinished signal is sent out after all jobs
> have been processed, and the job queue is empty for the first time. But
> this will only happen if *every single* job that was queued before
> actually went though its "activating" state and is not in
> "active". Hence there's really no point in waiting for any individual
> unit's state change, since looking at the system-wide state is enough
> and incorporates the individual unit's state changes

:) I don't think we are on the same page.

When a single unit becomes "active" why would we wait for other units
to become "active" too before we change the cpu share to the default
value. Services can change how long they are going to be in
"activating" state with sd_notify anyways.

With my propse, we don't do anything on StartupFinished but revert
back the cpu share of a service as soon as it becomes active.

Propose:
Activating A
Activating B
Set StartupCPUShares on A
Set StartupCPUShares on B
A becomes active
Revert StartupCPUShares with CPUShares on A
B becomes active
Revert StartupCPUShares with CPUShares on B
No more jobs
Send StartupFinished

Currently:
Activating A
Activating B
Set StartupCPUShares on A
Set StartupCPUShares on B
A becomes active
B becomes active
No more jobs
Revert StartupCPUShares with CPUShares on A
Revert StartupCPUShares with CPUShares on B
Send StartupFinished

Umut

>
> Lennart
>
> --
> Lennart Poettering, Red Hat