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Subject: Re: kworker/0:3+pm hogging CPU
To:     Michal Hocko <mhocko@suse.com>,
        Mathias Nyman <mathias.nyman@linux.intel.com>,
        Alan Stern <stern@rowland.harvard.edu>,
        Salvatore Bonaccorso <carnil@debian.org>
Cc:     LKML <linux-kernel@vger.kernel.org>,
        Greg KH <gregkh@linuxfoundation.org>,
        linux-usb@vger.kernel.org, "Rafael J. Wysocki" <rjw@rjwysocki.net>
References: <20200720173807.GJ1228057@rowland.harvard.edu>
 <20200720174530.GB4061@dhcp22.suse.cz>
 <20200720174812.GK1228057@rowland.harvard.edu>
 <20200720181605.GC4061@dhcp22.suse.cz>
 <20200720200243.GA1244989@rowland.harvard.edu>
 <20200721055917.GD4061@dhcp22.suse.cz>
 <20200721143325.GB1272082@rowland.harvard.edu>
 <20200829095003.GA2446485@eldamar.local>
 <20200829155949.GA499295@rowland.harvard.edu>
 <38dfdef4-f9ab-1755-8418-2285d843af86@linux.intel.com>
 <20200901152728.GI16650@dhcp22.suse.cz>
From:   Dirk Kostrewa <dirk.kostrewa@mailbox.org>
Message-ID: <f723f5a7-1b2e-e8d1-3b0b-201069b7a40c@mailbox.org>
Date:   Fri, 4 Sep 2020 17:57:16 +0200
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Hi,

meanwhile, I convinced Dell that I have a hardware issue (and not a 
Linux issue), and Dell has replaced the mainboard of my laptop. After 
that, both the USB over-current kernel messages and the kworker 
processes with permanent high CPU load are gone. So, this was indeed a 
hardware issue!

Many thanks for your feedback and help!

Best regards,

Dirk.

Am 01.09.20 um 17:27 schrieb Michal Hocko:

> On Mon 31-08-20 14:37:10, Mathias Nyman wrote:
> [...]
>> I can't come up with any good solution to this right now.
>> Only bad ideas such as
>> a. Add a sleep to the over-current case,
>>     doesn't solve anything else than the ~100% cpu hogging part of the problem
> This sounds like a better thing from the user space point of view. I do
> not have any insight on what kind of other side effects this might have
> so I didn't dare to try that on my piece of (broken) HW. I do not see
> the problem all the time and I plan to replace it soon anyway.
>
> Considering that tweaking the power management helps maybe that could be
> done automagically after many consecutive failures.
>
> Just my 2c