syzbot wrote: > > syzkaller has found reproducer for the following crash on > f3b5ad89de16f5d42e8ad36fbdf85f705c1ae051 "BUG: workqueue lockup" is not a crash. > git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/master > compiler: gcc (GCC) 7.1.1 20170620 > .config is attached > Raw console output is attached. > C reproducer is attached > syzkaller reproducer is attached. See https://goo.gl/kgGztJ > for information about syzkaller reproducers > > > BUG: workqueue lockup - pool cpus=1 node=0 flags=0x0 nice=0 stuck for 37s! > BUG: workqueue lockup - pool cpus=1 node=0 flags=0x0 nice=-20 stuck for 32s! > Showing busy workqueues and worker pools: > workqueue events: flags=0x0 > pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/256 > pending: cache_reap > workqueue events_power_efficient: flags=0x80 > pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=2/256 > pending: neigh_periodic_work, do_cache_clean > workqueue mm_percpu_wq: flags=0x8 > pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/256 > pending: vmstat_update > workqueue kblockd: flags=0x18 > pwq 3: cpus=1 node=0 flags=0x0 nice=-20 active=1/256 > pending: blk_timeout_work You gave up too early. There is no hint for understanding what was going on. While we can observe "BUG: workqueue lockup" under memory pressure, there is no hint like SysRq-t and SysRq-m. Thus, I can't tell something is wrong. At least you need to confirm that lockup lasts for a few minutes. Otherwise, this might be just overstressing. (According to repro.c , 12 threads are created and soon SEGV follows? According to above message, only 2 CPUs? Triggering SEGV suggests memory was low due to saving coredump?) -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
