Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Mon, 31 Aug 2020 14:38:47 +0900
From:   Norbert Preining <norbert@preining.info>
To:     linux-kernel@vger.kernel.org
Subject: kernel hard lockups wit 5.9-rc{2,3}
Message-ID: <20200831053847.GA5022@bulldog.preining.info>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Dear all,

(please Cc)

I am seeing hard lockups with 5.9-rc2 and -rc3, while 5.8.N (1,2,3,4,5)
work without any problems.

THe lockups are hard to debug, since not even Sysrq works anymore. The
screen freezes completely, no reaction. Ports are also dead, ssh into
the machine is not possible.

Hangs are repeatable, but not triggerable (at least I didn't find a
way). Last time I left the screen locked and went shopping to find it
locked up coming back. In total I got about 10 lock ups.

This is an Intel CPU with AMD 5700xt GPU, running Debian/unstable.

My feeling is somehow GPU related, but that might be a wide grasp.

Any suggestions how to debug this? The kernel logs after reboot are
empty.

Best

Norbert

--
PREINING Norbert                              https://www.preining.info
Accelia Inc. + IFMGA ProGuide + TU Wien + JAIST + TeX Live + Debian Dev
GPG: 0x860CDC13   fp: F7D8 A928 26E3 16A1 9FA0 ACF0 6CAC A448 860C DC13