On Tue, Aug 13, 2019 at 5:06 PM David Howells <[email protected]> wrote: > > Dmitry Vyukov <[email protected]> wrote: > > > > I meant that I don't know how to turn a tracepoint on from inside the > > > kernel. > > > > This /sys/kernel/debug/tracing/events/rxrpc/rxrpc_local/enable in: > > echo 1 > /sys/kernel/debug/tracing/events/rxrpc/rxrpc_local/enable > > should map to some global variable, right? If so, it should be > > possible to initialize that var to 1 statically. Or that won't work > > for some reason? > > As I understand it, it's all hidden inside of tracing macros and ftrace > infrastructure and involves runtime patching the code to enable tracepoints > (they're effectively NOP'ed out when not in use). > > So, no, it's not that simple. > > I asked Steven and he says: > > trace_set_clr_event("sched", "sched_switch", 1); > > is the same as > > echo 1 > events/sched/sched_switch/enable > > So it can be done. Will syzbot actually collect the trace log?
It only collects console output. I don't know what is trace log. If the trace log is not console output, then it won't.
