From: "Ludovic Courtès" <ludo@gnu.org>
To: Maxim Cournoyer <maxim.cournoyer@gmail.com>
Cc: 55444@debbugs.gnu.org
Subject: bug#55444: elogind startup race between shepherd and dbus-daemon
Date: Wed, 25 May 2022 14:45:50 +0200 [thread overview]
Message-ID: <87tu9dhjb5.fsf@gnu.org> (raw)
In-Reply-To: <87y1yr4qd3.fsf@gmail.com> (Maxim Cournoyer's message of "Mon, 23 May 2022 22:27:20 -0400")
Hi,
Maxim Cournoyer <maxim.cournoyer@gmail.com> skribis:
> Ludovic Courtès <ludo@gnu.org> writes:
>
>> Hello!
>>
>> Currently (40a729a0e6f1d660b942241416c1e2c567616d4d), shepherd and
>> dbus-daemon compete to start elogind: shepherd tries to start it
>> eagerly, and dbus-daemon starts it on-demand upon bus activation.
>>
>> Sometimes dbus-daemon wins, and thus shepherd tries a few times to start
>> it anyway, leading to the infamous:
>>
>> elogind is already running as PID 123
>
> Do we have a system test that sometimes reproduce it, or at least the
> above message?
Any system along the lines of gnu/system/examples/desktop.tmpl gets this
message, though usually Xorg starts without any problem.
There’s an elogind system test but it doesn’t catch the problem because
it’s a non-deterministic and rather rare issue.
> I have some branch where I introduce some D-Bus synchronization
> primitives I had started to fix
> https://issues.guix.gnu.org/issue/52051, which ended up being fixed
> differently (bumping the timeout value); perhaps it could be of use
> here.
Hmm I had forgotten about that bug, and I wonder if it’s the same bug I
was seeing, and that in fact the shepherd/dbus-daemon race isn’t the
root cause. The machine where I saw elogind startup failures was
extremely slow to start for other reasons.
Anyhow, getting rid of this race seems like the right thing to do.
Ludo’.
next prev parent reply other threads:[~2022-05-25 12:46 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-16 8:26 bug#55444: elogind startup race between shepherd and dbus-daemon Ludovic Courtès
2022-05-24 2:27 ` Maxim Cournoyer
2022-05-25 12:45 ` Ludovic Courtès [this message]
2022-05-24 19:25 ` Liliana Marie Prikler
2022-05-25 12:26 ` Ludovic Courtès
2022-05-27 13:54 ` Ludovic Courtès
2022-05-27 20:54 ` Ludovic Courtès
2022-05-28 8:13 ` Josselin Poiret via Bug reports for GNU Guix
2022-05-28 21:26 ` Ludovic Courtès
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