linux-kernel - Re: [PATCH v4] driver core: shut down devices asynchronously

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <2023100507-refocus-stooge-08dd@gregkh>
Date:   Thu, 5 Oct 2023 11:36:21 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     Stuart Hayes <stuart.w.hayes@...il.com>
Cc:     linux-kernel@...r.kernel.org,
        "Rafael J . Wysocki" <rafael@...nel.org>,
        Tanjore Suresh <tansuresh@...gle.com>,
        Martin Belanger <Martin.Belanger@...l.com>,
        Oliver O'Halloran <oohall@...il.com>,
        Daniel Wagner <dwagner@...e.de>,
        Keith Busch <kbusch@...nel.org>, Lukas Wunner <lukas@...ner.de>
Subject: Re: [PATCH v4] driver core: shut down devices asynchronously

On Thu, Sep 21, 2023 at 11:34:43AM -0500, Stuart Hayes wrote:
> Shut down devices asynchronously, ensuring that each device is shut down
> before its parents.
> 
> This can dramatically reduce system shutdown/reboot time on systems that
> have devices that take many seconds to shut down, such as some NVMe drives.
> On one system tested, the shutdown time went from 11 minutes without this
> patch to 55 seconds with the patch.

That's a nice improvement, but I think we need a lot more testing on a
wide range of systems before we can take a patch like this.

Also, what about busses that don't want this type of shutdown?  We allow
busses to opt-in for async probing, shouldn't that be also done for
shutting them down to resolve issues for busses that can not handle
this?

thanks,

greg k-h