On Thu, 30 Apr 2015 07:36:40 -0700 Jerry Snitselaar <[email protected]> wrote:
> Critical tracepoint hooks shoud never call anything that takes a lock, > so they are unable to call getrawmonotonic() or ktime_get(). > > Export the rest of the tracing clock functions so can be used in > tracepoint hooks. A little background needs to be explained here. A customer adds their own module to do some analysis and hooks to tracepoints to do so. They were using ktime_get() as their time source, but as that grabs a seq lock, it was causing deadlocks. The tracing clocks were made for this purpose, and I find nothing wrong with letting users add their own modules (GPL of course) and adding their own hooks to the tracepoint code. I created it for that purpose. But if they need to do any timings, they must use lockless clocks, which the trace clocks are good for. -- Steve > > Cc: Steven Rostedt <[email protected]> > Cc: Ingo Molnar <[email protected]> > Signed-off-by: Jerry Snitselaar <[email protected]> > --- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
