linux-kernel - Re: Worker threads in D state since c5a94a618e7ac86 (workqueue: Use TASK

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]

Date:   Mon, 11 Sep 2017 16:21:33 +0200
From:   Markus Trippelsdorf <markus@...ppelsdorf.de>
To:     Tejun Heo <tj@...nel.org>
Cc:     Peter Zijlstra <peterz@...radead.org>,
        linux-kernel@...r.kernel.org,
        "Luis R. Rodriguez" <mcgrof@...nel.org>,
        "Eric W. Biederman" <ebiederm@...ssion.com>,
        "Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>
Subject: Re: Worker threads in D state since c5a94a618e7ac86 (workqueue: Use
 TASK_IDLE)

On 2017.09.11 at 06:11 -0700, Tejun Heo wrote:
> Hello,
>
> On Sun, Sep 10, 2017 at 09:36:53AM +0200, Markus Trippelsdorf wrote:
> > Since:
> >
> >  commit c5a94a618e7ac86b20f53d947f68d7cee6a4c6bc
> >  Author: Peter Zijlstra <peterz@...radead.org>
> >  Date:   Wed Aug 23 13:58:44 2017 +0200
> >
> >      workqueue: Use TASK_IDLE
> >
> >
> > all worker threads are in D state. They all show up when using "magic
> > SysRq w". In htop they all have big fat red 'D' in the state column.
> > Is this really desirable?
> >
> > I have attached the output of "ps aux" after boot and the SysRq-w
> > output.
>
> Hmm.... looks like we better revert until we figure out how this
> should get presented in debugging facilities / to userspace.  Peter?

BTW rcu recently introduced the same issue:

 commit d5374226c3e444239e063f005dfb59cae4390db4
 Author: Luis R. Rodriguez <mcgrof@...nel.org>
 Date:   Tue Jun 20 14:45:47 2017 -0700

     rcu: Use idle versions of swait to make idle-hack clear

--
Markus