Re: [yocto] Limiting Yocto Memory Usage

Hi Randy,

On Tue, Jul 21 2026 at 11:22 -0400, Randy MacLeod <randy.macleod@windriver.=
com> wrote:
> On 2026-07-16 04:22, Ulrich =C3=96lmann via lists.yoctoproject.org wrote:
> >
> > Hey Luis,
> >
> > On Fri, Jul 10 2026 at 15:26 -0600, "Luis Merayo via lists.yoctoproject=
.org"<[email protected]> wrote:
> >>
> >> Hi,
> >>
> >> I would like to know if there is a way to limit Bitbake's Memory usage
> >> to a specific percentage of the available RAM. For example, can the
> >> Yocto build be limited to use a maximum of 70% of RAM?
> > if you are doing your Bitbake work on a machine running a systemd based
> > Linux distribution you could simply do something like
> >
> >    $ systemd-run \
> >         --user \
> >         --scope \
> >         --property=3DCPUWeight=3D<YOUR_CPUWEIGHT> \
> >         --property=3DIOWeight=3D<YOUR_IOWEIGHT> \
> >         --property=3DMemoryHigh=3D<YOUR_MEMORYHIGH> \
> >         --property=3DOOMPolicy=3Dkill \
> >         --unit=3D"bitbake-run" \
> >         bitbake [...]
> >
> > to somewhat limit the resources, see systemd.resource-control(5) and
> > systemd.scope(5) for details regarding the used parameters.
> >
> > Best regards,
> > Ulrich
>
>
> Hi Ulrich,
>
> Using systemd-run is something that I've been meaning to try so it's good=
 to
> hear that you're doing it.
>
> Do you have any experiences to share about this approach ?

we currently use the systemd-run approach mainly to make resource
sharing on our build servers a bit fairer between colleagues when
building customer BSPs.

One nice side effect is that every single process of the control group
gets terminated when the systemd-run scope is terminated. No stray
processes are left behind by mistake.

> Do you do world builds?

So far, I am not using it for world builds. Our use case is more about
encapsulating individual build jobs and avoiding that a single build
grabs too much of the machine, rather than stress-testing the setup with
"bitbake world".

> Do you run more than one systemd-run build on a given machine?

Yes, in practice we do end up with multiple builds running in parallel
on the same machine, since (hopefully ;) all colleagues use the same
systemd-run approach.

> Of course it doesn't prevent bitbake from pushing the cgroup contained sy=
stem
> harder that it can handle and bitbake doesn't have any feedback so that's
> something
> to consider when doing the jobserver or free memory build regulation work.

Right. For our purpose, though, it works reasonably well as a pragmatic
way to improve sharing/fairness on multi-user build machines.

Best regards,
Ulrich


> ../Randy
>
>
> >
> >
> >> Could these three variables achieve this?
> >>
> >>   BB_PRESSURE_MAX_CPU, BB_PRESSURE_MAX_IO , BB_PRESSURE_MAX_MEMORY
> >>
> >> I see the range for these variables is from 1 to 1000000, so I would
> >> like to understand if there is a way to specify their values as a
> >> function of the available RAM.
> >>
> >> Regards,
> >>
> >> Luis
> >>
> >>
> >> This email and any attachments are intended for the sole use of the na=
med recipient(s) and contain(s) confidential
> >> information that may be proprietary, privileged, or copyrighted under =
applicable law. If you are not the intended
> >> recipient, do not read, copy, or forward this email message or any att=
achments, delete this email message and any
> >> attachments immediately.
> >>
> >>
> >>
> >> -=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-
> >> Links: You receive all messages sent to this group.
> >> View/Reply Online (#66645):https://lists.yoctoproject.org/g/yocto/mess=
age/66645
> >> Mute This Topic:https://lists.yoctoproject.org/mt/120272854/3616765
> >> Group Owner:[email protected]
> >> Unsubscribe:https://lists.yoctoproject.org/g/yocto/unsub [randy.macleo=
[email protected]]
> >> -=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-
> >>
>
> --
> # Randy MacLeod
> # Wind River Linux
--=20
Pengutronix e.K.                           | Ulrich =C3=96lmann            =
   |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |