linux-kernel - Re: [RFC 5/5] pm: remove kernel thread freezing

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: <nycvar.YFH.7.76.1710032248470.17517@jbgna.fhfr.qr>
Date:   Tue, 3 Oct 2017 22:51:50 +0200 (CEST)
From:   Jiri Kosina <jikos@...nel.org>
To:     Bart Van Assche <Bart.VanAssche@....com>
cc:     "pavel@....cz" <pavel@....cz>,
        "darrick.wong@...cle.com" <darrick.wong@...cle.com>,
        "viro@...iv.linux.org.uk" <viro@...iv.linux.org.uk>,
        "ming.lei@...hat.com" <ming.lei@...hat.com>,
        "rjw@...ysocki.net" <rjw@...ysocki.net>,
        "mcgrof@...nel.org" <mcgrof@...nel.org>,
        "linux-fsdevel@...r.kernel.org" <linux-fsdevel@...r.kernel.org>,
        "len.brown@...el.com" <len.brown@...el.com>,
        "tytso@....edu" <tytso@....edu>,
        "boris.ostrovsky@...cle.com" <boris.ostrovsky@...cle.com>,
        "ONeukum@...e.com" <ONeukum@...e.com>,
        "linux-block@...r.kernel.org" <linux-block@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "nborisov@...e.com" <nborisov@...e.com>,
        "oleg.b.antonyan@...il.com" <oleg.b.antonyan@...il.com>,
        "linux-pm@...r.kernel.org" <linux-pm@...r.kernel.org>,
        "linux-xfs@...r.kernel.org" <linux-xfs@...r.kernel.org>,
        "jgross@...e.com" <jgross@...e.com>,
        "martin.petersen@...cle.com" <martin.petersen@...cle.com>,
        "oleksandr@...alenko.name" <oleksandr@...alenko.name>,
        "todd.e.brandt@...ux.intel.com" <todd.e.brandt@...ux.intel.com>,
        "jack@...e.cz" <jack@...e.cz>
Subject: Re: [RFC 5/5] pm: remove kernel thread freezing

On Tue, 3 Oct 2017, Jiri Kosina wrote:

> > What about the many drivers outside filesystems that use the 
> > set_freezable() / try_to_freeze() / wait_event_freezable() API?
> 
> Many/most of them are just completely bogus and pointless. 

More specifically -- they don't really care at all whether they get 
scheduled out exactly at the try_to_freeze() point; they are perfectly 
happy being scheduled out at any other scheduling point, and land on 
runqueue after the resume has been completed.

Sure, certain drivers need to take action when system is undergoing 
hibernation/suspend. But that's what PM callbacks are for, not kthread 
hibernation.

-- 
Jiri Kosina
SUSE Labs