Hello, we are observing system hangs after upgrading kernel from 4.1 to 4.4. This happens on a database server running MariaDB, hot backuping with Percona Xtrabackup and when doing rsync (mostly deletion on the server). Happens on three different servers, on both ext4 and xfs. Can be reproduced on kernel 4.4.55, 4.9.16, does not happen with kernel 4.1.39. This is a virtual machine (xen-domU) having disks on lvm. There is nothing in dmesg, but server load goes up, cannot even do `lsof` or `cat` files. A hard system reboot of the virtual machine puts it back to normal. https://bugs.launchpad.net/percona-xtrabackup/+bug/1625984 https://jira.mariadb.org/browse/MDEV-10852
Created attachment 255453 [details] sysrq-l.log echo l > /proc/sysrq-trigger
Created attachment 255455 [details] sysrq-m.log echo m > /proc/sysrq-trigger
Created attachment 255457 [details] sysrq-w.log echo w > /proc/sysrq-trigger
Sadly, this is not related to https://bugzilla.kernel.org/show_bug.cgi?id=119841
Created attachment 256765 [details] sysrq-w.log (case 2) sysrq-w.log (case 2)
Attached a new occurrence with kernel 4.4.67.
Cannot reproduce with kernel 4.12+. Maybe related to #193331.