and when I say, I don't know whether that makes sense or not, it's because I don't know whether all the snapshot info is in the trace anyway. (I need to play with the new snapshot feature first) On Thu, Sep 12, 2013 at 1:39 PM, John Kacur <jkacur@xxxxxxxxxx> wrote: > I don't know whether this makes sense or not, but I believe he is > asking to have trace_on and snapshot on simultaneously. He wants to do > a trace, but also have the snapshot information that coincides with > the start and end of the trace. > > On Thu, Sep 12, 2013 at 1:09 PM, Steven Rostedt <rostedt@xxxxxxxxxxx> wrote: >> On Thu, 12 Sep 2013 04:58:41 +0000 >> "Du, Yuyang" <yuyang.du@xxxxxxxxx> wrote: >> >>> Thanks, Steve. >>> >>> Virtually, what I want is: >>> >>> tracing_on(1), snapshort, traces..., snapshot, tracing_on(0). >>> >>> If I understand right, I need the new feature "snapshot" in ftrace. But, it seems snapshot and ftrace are separated, which does not satisfy my need. >>> >> >> I don't understand what you mean by "snapshot and ftrace are >> separated"? The snapshot feature is part of ftrace. Basically, you have >> two buffers: an active one, and a static one. When you echo 1 into the >> snapshot file, it swaps the two buffers. The active one becomes the >> static one, and the static one becomes the active one. >> >> This allows you to save off a trace while tracing continues. >> >> -- Steve >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-trace-users" in >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-trace-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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