Qu Wenruo wrote: >> Ok. Finally have a sysrq+w output of 4.19.8. >> The uptime of this system has been a few days. It has already received quite >> some btrfs-sends in that time (every night). When the sysrq+w output was >> taken, the system started to get more and more processes in a D kernel state >> bordering on becoming unusable. I had to hard-reset the system after this >> to get it going again. >It's caused by qgroup, and a dead lock on btrfs_drop_snapshot(). >This is one of the easiest way to trigger an ABBA deadlock. >Please either disable qgroup or apply this patch to solve it: >https://patchwork.kernel.org/patch/10725371/ Any idea in which kernel version this patch is/will be included? -- Stephen.
