Messages in this thread | | | Date | Mon, 23 Feb 2009 19:09:41 +0100 | From | Ingo Molnar <> | Subject | Re: [PATCH] tracing/ftrace: add missing wake-up on some callsites |
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* Steven Rostedt <rostedt@goodmis.org> wrote:
> On Mon, 23 Feb 2009, Ingo Molnar wrote: > > > * Steven Rostedt <rostedt@goodmis.org> wrote: > > > > > > Which would send a delayed work to wake up? > > > > > > No, I was thinking that trace_delay_wake_up() would be > > > called by these dangerous call sites. Then a per_cpu flag > > > could be set. We could have a trace point in the scheduler > > > code that is outside holding a runqueue lock, and this > > > trace point would call a trace function that will clear > > > the per cpu flag, and then call trace_wake_up(). > > > > No, that's very roundabout and ugly. If we putting a > > tracepoint there we might as well put real scheduler code > > there that looks for such a flag. But i'm not convinced we > > need a flag ... > > Just a suggestion. I was trying to keep the tracer from being > an overhead. But what else would you suggest? Just having the > scheduler call trace_wakeup?
i think we could use a TIF flag to trigger a wakeup at the return-to-userspace (or return-from-IRQ) stage or so?
Ingo
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