Hi, I think there is a flaw in the current preempt-rt 4.14 patch (probably since v4.14.302-rt142). The "0515-timers-Prepare-support-for-PREEMPT_RT.patch" uses at two location the following configure option: #ifdef CONFIG_PREEMPT_RT I guess that "CONFIG_PREEMPT_RT" is not defined for the 4.14-rt kernel and should be "CONFIG_PREEMPT_RT_FULL" instead, or? The problem that I was facing was that a tcdrain() call from userspace was spinning forever. I traced this down to an endless loop in del_timer_sync(). After replacing "CONFIG_PREEMPT_RT" with "CONFIG_PREEMPT_RT_FULL", the problem seems to be fixed. Regards, Andre
