Darcy, On Tue, 6 Apr 2010, Darcy Watkins wrote: Please do not top post. > Hi Thomas, > > Thanks for the suggestion. > > I tried boosting priority of [irq/16-serial] to 70 and then 95 with no > observable difference from before. I still see the input overruns when > I up-arrow to backup through shell history (and the terminal sends > up-arrow escape sequences as small serial bursts at 115200). > > /proc/interrupts also indicates that serial interrupts do count upwards > in good quantity. Ok. Can you try to fire up the function tracer to figure out what's happening ? Unfortunately n_tty_receive_overrun() is an inline function. Can you make it a non inline so it gets covered by the function tracer ? Then you can magically stop the tracer with a filter: # echo 'n_tty_receive_overrun:traceoff' > DEBUGFSMOUNTPOINT/tracing/set_ftrace_filter Further info about the tracer is here: http://lwn.net/Articles/370423/ If you have a trace please put it up to some ftp/http site or mail it to me privately. Thanks, tglx -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
