On Fri, Aug 21, 2020 at 05:03:34PM -0400, Steven Rostedt wrote: > > Sigh. Is it too hard to make mutex_trylock() usable from interrupt > > context? > > > That's a question for Thomas and Peter Z.
You should really know that too, the TL;DR answer is it's fundamentally buggered, can't work. The problem is that RT relies on being able to PI boost the mutex owner. ISTR we had a thread about all this last year or so, let me see if I can find that. Here goes: https://lkml.kernel.org/r/20191218135047.gs2...@hirez.programming.kicks-ass.net Kexec even gets mentioned: https://lkml.kernel.org/r/20191219090535.gv2...@hirez.programming.kicks-ass.net