mmap issue with 22.04.3 and kernel 6.2

[Mauricio Faria de Oliveira]

On Tue, Aug 22, 2023 at 4:30 PM Mauricio Faria de Oliveira
<mfo at canonical.com> wrote:
>
> Hi Mathieu,
>
> On Tue, Aug 22, 2023 at 11:20 AM Mathieu Fluhr <mathieu.fluhr at gmail.com> wrote:
> >
> > Hello,
> >
> > First of all, I apologize if this is not the right place to report a bug, but for some obscure reason, I cannot login to launchpad with my Ubuntu One account (I always end up on the "Ooops" page...).
>
> No worries, thanks for reporting an issue in some way.
> (For the login issue, see login.ubuntu.com > Support > Other > "When I
> try to log in, I get an "OOPS" message. What should I do?")
>
> If this helps, please know that in the future, you can reach out to
> our kernel team specifically, kernel-team at lists.ubuntu.com [2].
>
> >
> > I am compiling (daily) the Android OS (AOSP) which makes a heavy use of hardware resources and several parts of it relies on the mmap() system call. Updating to 22.04.3 last Thursday started to trigger several (non-consistent) build errors, all related to mmap(), claiming that it can't allocate memory.... which is not consistent with the fact that my workstation still had 50GB+ free RAM at that time.
> >
> > Digging a bit into the issue, I found out that it was a known issue, and that the fix has been merged in the 6.1 LTS kernel [1] but unfortunately not in 6.2, since the patch appeared after the last 6.2.16 release.
> >
> > I applied it locally and rebuilt a new kernel, and I can confirm this fixes the issue.
> > Could it be possible to think about applying it to the official 6.2 ubuntu package so that I don't have to always "downgrade" to the old 5.19 coming from 22.04.2 ?
> >
> > Kind Regards,
> > Mathieu
> >
> > [1] https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/lib/maple_tree.c?h=v6.1.45&id=254ee530286aeb6d6de93d05b2247153df590af1
>
> Looking at the patch [1] ...
> """
> maple_tree: make maple state reusable after mas_empty_area()
> commit 0257d9908d38c0b1669af4bb1bc4dbca1f273fe6 upstream.
> """
> ... and the lunar/6.2-based kernel package git repo, it should be
> available in lunar-proposed.

Sorry, you're on jammy (22.04.x) with the 6.2 HWE kernel from lunar,
not on lunar.
It's also available in jammy-proposed; see below.

>
> Could you please test it?
>
> $ git remote get-url origin
> git://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/lunar
>
> $ git log --oneline origin/master-next -- lib/maple_tree.c | head -n1
> a08052779ad6 maple_tree: make maple state reusable after mas_empty_area()
>
> $ git show a08052779ad6 | grep 'commit .* upstream'
>     commit 0257d9908d38c0b1669af4bb1bc4dbca1f273fe6 upstream.
>
> $ git describe --contains a08052779ad6
> Ubuntu-6.2.0-30.30~288
>
> $ rmadison -a source linux | grep lunar
>  linux | 6.2.0-20.20    | lunar           | source
>  linux | 6.2.0-27.28    | lunar-security  | source
>  linux | 6.2.0-27.28    | lunar-updates   | source
>  linux | 6.2.0-32.32    | lunar-proposed  | source
>
> $ sudo add-apt-repository -yp proposed
>
> ubuntu at lunar:~$ apt policy linux-image-6.2.0-32-generic
> ...
>         100 http://archive.ubuntu.com/ubuntu lunar-proposed/main amd64 Packages
>         100 http://security.ubuntu.com/ubuntu lunar-proposed/main amd64 Packages
>
> $ sudo apt install linux-image-6.2.0-32-generic
> $ ... reboot
>

$ rmadison -a source linux-hwe-6.2
 linux-hwe-6.2 | 6.2.0-26.26~22.04.1 | jammy-security | source
 linux-hwe-6.2 | 6.2.0-26.26~22.04.1 | jammy-updates  | source
 linux-hwe-6.2 | 6.2.0-32.32~22.04.1 | jammy-proposed | source

$ rmadison -a amd64 linux-image-6.2.0-32-generic
 linux-image-6.2.0-32-generic | 6.2.0-32.32~22.04.1 | jammy-proposed | amd64
 linux-image-6.2.0-32-generic | 6.2.0-32.32         | lunar-proposed | amd64

So, the steps above should work on jammy too.

> cheers,
>
> [2] https://lists.ubuntu.com/mailman/listinfo/kernel-team
>
> > --
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>
>
> --
> Mauricio Faria de Oliveira



-- 
Mauricio Faria de Oliveira