Hi Julien, On 2019-03-26, Julien Grall <julien.grall@xxxxxxx> wrote: >>> [...] >>> [ 1.169151] 002: Serial: AMBA PL011 UART driver >>> [ 1.254891] 002: 7ff80000.uart: ttyAMA0 at MMIO 0x7ff80000 (irq = 32, base_baud = 0) is a PL011 rev3 >>> [ 1.255007] 002: printk: console [ttyAMA0] enabled >> >> The ttyAMA drivers do not have support for atomic printing, so it is >> not the new atomic feature that is causing the mangling. For your >> setup, all printk console printing is being handled within a specific >> context, the printk kernel thread. > > This series is somehow making worst when using ttyAMA0. I haven't see > any mangling with 4.19-rt. I will setup some tests using systemd on 4.19 and 5.0 to see if I can see what is going on. It seems there may be some synchronization missing between the printk kernel thread and /dev/console. John Ogness
