> On Jul 19, 2023, at 7:20 PM, NeilBrown <neilb@xxxxxxx> wrote: > > On Wed, 19 Jul 2023, Chuck Lever III wrote: >> >>> On Jul 18, 2023, at 9:16 PM, NeilBrown <neilb@xxxxxxx> wrote: >>> >>> On Tue, 18 Jul 2023, Chuck Lever wrote: >>>> On Tue, Jul 18, 2023 at 04:38:08PM +1000, NeilBrown wrote: >>>>> No callers of svc_pool_wake_idle_thread() care which thread was woken - >>>>> except one that wants to trace the wakeup. For now we drop that >>>>> tracepoint. >>>> >>>> That's an important tracepoint, IMO. >>>> >>>> It might be better to have svc_pool_wake_idle_thread() return void >>>> right from it's introduction, and move the tracepoint into that >>>> function. I can do that and respin if you agree. >>> >>> Mostly I agree. >>> >>> It isn't clear to me how you would handle trace_svc_xprt_enqueue(), >>> as there would be no code that can see both the trigger xprt, and the >>> woken rqst. >>> >>> I also wonder if having the trace point when the wake-up is requested >>> makes any sense, as there is no guarantee that thread with handle that >>> xprt. >>> >>> Maybe the trace point should report when the xprt is dequeued. i.e. >>> maybe trace_svc_pool_awoken() should report the pid, and we could have >>> trace_svc_xprt_enqueue() only report the xprt, not the rqst. >> >> I'll come up with something that rearranges the tracepoints so that >> svc_pool_wake_idle_thread() can return void. > > My current draft code has svc_pool_wake_idle_thread() returning bool - > if it found something to wake up - purely for logging. This is also where I have ended up. I'll post an update probably tomorrow my time. Too much other stuff going on to finish it today. > I think it is worth logging whether an event triggered a wake up or not, > and which event did that. Agreed. I have some experimental code that records _RET_IP_ of the caller of svc_xprt_enqueue(), but again it's questionable whether that is of long term value. > I'm less you that the pid is relevant. But > as you say - this will probably become clearer as the code settles down. > > Thanks, > NeilBrown > > >> >> svc_pool_wake_idle_thread() can save the waker's PID in svc_rqst >> somewhere, for example. The dequeue tracepoint can then report that >> (if it's still interesting when we're all done with this work). >> >> >> -- >> Chuck Lever -- Chuck Lever
