On Thu, 7 Mar 2019, Sergey Senozhatsky wrote: > On (03/06/19 11:07), Mikulas Patocka wrote: > > This bug only happens if we select large logbuffer (millions of > > characters). With smaller log buffer, there are messages "** X printk > > messages dropped", but there's no lockup. > > > > The kernel apparently puts 2 million characters into a console log buffer, > > then takes some lock and than tries to write all of them to a slow serial > > line. > > Do you run a preemtible kernel? > > -ss The kernel has voluntary preemption. Mikulas
