From mboxrd@z Thu Jan  1 00:00:00 1970
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1759541AbcISHQl (ORCPT <rfc822;robin@linux-mips.org> + 2 others);
        Mon, 19 Sep 2016 03:16:41 -0400
Received: from mail.virtall.com ([178.63.195.102]:56705 "EHLO mail.virtall.com"
        rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
        id S1756367AbcISHQc (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
        Mon, 19 Sep 2016 03:16:32 -0400
X-Greylist: delayed 478 seconds by postgrey-1.27 at vger.kernel.org; Mon, 19 Sep 2016 03:16:32 EDT
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII;
 format=flowed
Content-Transfer-Encoding: 7bit
Date: Mon, 19 Sep 2016 16:08:28 +0900
From: Tomasz Chmielewski <mangoo@wpkg.org>
To: LKML <linux-kernel@vger.kernel.org>
Subject: thousands of kworker processes with 4.7.x and 4.8-rc*
Message-ID: <35b2acf87bfeaf1d04f2cf3d10b99b6e@admin.virtall.com>
User-Agent: Roundcube Webmail/1.2.0
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
Return-Path: <linux-kernel-owner@vger.kernel.org>

On several servers running 4.7.x and 4.8-rc6/7 kernels I'm seeing 
thousands of kworker processes.

# ps auxf|grep -c kworker
2104


Load average goes into hundreds on a pretty much idle server (biggest 
CPU and RAM consumers are probably SSHD with one user logged in and 
rsyslog writing ~1 line per minute):

# uptime
  06:58:56 up 26 min,  1 user,  load average: 146.11, 215.46, 105.70


# uptime
  06:59:48 up 26 min,  1 user,  load average: 305.20, 240.84, 120.25


Sometimes seeing lots of them in "D" state:

root     19474  0.0  0.0      0     0 ?        D    06:54   0:00  \_ 
[kworker/0:208]
root     19475  0.0  0.0      0     0 ?        D    06:54   0:00  \_ 
[kworker/0:209]
root     19477  0.0  0.0      0     0 ?        D    06:54   0:00  \_ 
[kworker/0:211]
root     19480  0.0  0.0      0     0 ?        D    06:54   0:00  \_ 
[kworker/0:214]
root     19483  0.0  0.0      0     0 ?        D    06:54   0:00  \_ 
[kworker/0:217]
root     19485  0.0  0.0      0     0 ?        D    06:54   0:00  \_ 
[kworker/0:219]
root     19486  0.0  0.0      0     0 ?        D    06:54   0:00  \_ 
[kworker/0:220]
root     19487  0.0  0.0      0     0 ?        D    06:54   0:00  \_ 
[kworker/0:221]
root     19492  0.0  0.0      0     0 ?        D    06:54   0:00  \_ 
[kworker/0:226]
root     19533  0.0  0.0      0     0 ?        D    06:54   0:00  \_ 
[kworker/4:257]


Is it a known issue?

The server has 8 CPUs and 32 GB RAM.


Tomasz Chmielewski
https://lxadm.com