From: Lennart Poettering <lennart@poettering.net>
To: "Zbigniew Jędrzejewski-Szmek" <zbyszek@in.waw.pl>
Cc: devicetree <devicetree@vger.kernel.org>,
systemd-devel@lists.freedesktop.org,
"linux-ide@vger.kernel.org" <linux-ide@vger.kernel.org>,
Hans de Goede <hdegoede@redhat.com>,
Mark Brown <broonie@kernel.org>,
linux-arm-kernel <linux-arm-kernel@lists.infradead.org>
Subject: Re: Making udev emit a signal when it is done loading modules
Date: Wed, 28 Jan 2015 02:38:52 +0100 [thread overview]
Message-ID: <20150128013852.GA8177@gardel-login> (raw)
In-Reply-To: <20150117160319.GO18247@in.waw.pl>
On Sat, 17.01.15 17:03, Zbigniew Jędrzejewski-Szmek (zbyszek@in.waw.pl) wrote:
> On Sat, Jan 17, 2015 at 09:44:00AM +0100, Hans de Goede wrote:
> > We would like
> > udev to emit a signal (ABI to be discussed) when it is done
> > trying to load modules for everything which was already enumerated
> > when it starts, iow when there are no new device events pending
> > anymore when udev does its initial hotplug replay.
> I think you can just create a unit like:
>
> # disable-new-hardware.service
> [Unit]
> After=systemd-udev-settle.service systemd-modules-load.service
> Wants=systemd-udev-settle.service
>
> [Service]
> Type=oneshot
> RemainAfterExit=yes
> ExecStart=/usr/local/bin/ping-the-kernel
>
> > So the question to you is would you be willing to include such
> > functionality in udev?
> I don't think udevd has enough knowledge. But a systemd unit like
> the one above should work.
To clarify this: if people do this, then this pulls in
systemd-udev-settle.service, which slows down boot. Every service that
does that is hence a majour source of slowness.
It's a hack to use this, not a solution.
Lennart
--
Lennart Poettering, Red Hat
_______________________________________________
systemd-devel mailing list
systemd-devel@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/systemd-devel
next prev parent reply other threads:[~2015-01-28 1:38 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-17 8:44 Making udev emit a signal when it is done loading modules Hans de Goede
2015-01-17 13:56 ` Greg KH
2015-01-17 14:12 ` [systemd-devel] " Mark Brown
2015-01-17 14:52 ` Hans de Goede
[not found] ` <20150117135630.GA25585-U8xfFu+wG4EAvxtiuMwx3w@public.gmane.org>
2015-01-17 15:23 ` [systemd-devel] " jonsmirl-Re5JQEeQqe8AvxtiuMwx3w
2015-01-17 16:03 ` David Herrmann
2015-01-17 16:03 ` Zbigniew Jędrzejewski-Szmek
2015-01-17 16:45 ` [systemd-devel] " Kay Sievers
2015-01-28 1:38 ` Lennart Poettering [this message]
2015-02-11 5:28 ` Mark Brown
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20150128013852.GA8177@gardel-login \
--to=lennart@poettering.net \
--cc=broonie@kernel.org \
--cc=devicetree@vger.kernel.org \
--cc=hdegoede@redhat.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-ide@vger.kernel.org \
--cc=systemd-devel@lists.freedesktop.org \
--cc=zbyszek@in.waw.pl \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).