Kernel freeze on AMD FX-9590 CPU during I/O

From: Dmitrii Tcvetkov
Date: Thu Oct 12 2017 - 16:08:20 EST


Hello,

Since linux kernel 4.14-rc1 almost any I/O has a chance to freeze kernel
(no log in /dev/tty0 nor /dev/ttyS0 not netconsole, no ARP answer over
network) on one of my machines. Compiling linux kernel reproduces the
issue reliably so far.

Bisecting between v4.13 and v4.14-rc1 led me to commit
94b1b03b519b81c494900cb112aa00ed205cc2d9
Also I created a bug in bugzilla, bisect log is attached there:
https://bugzilla.kernel.org/show_bug.cgi?id=197209

Unfortunately I can't test reverting of the commit on current mainline
due to revert conflicts and I don't know how to resolve them correctly.

My machine:
CPU: AMD FX-9590
RAM: non-ECC DDR 12 Gb
Storage layout: btrfs on top LVM on top LUKS on top HDD