No invalid histogram error

[Masami Hiramatsu <mhiramat@kernel.org>]

Hi Tom,

I'm trying to use histogram on a synthetic event, but faced an odd situation.

There is a synthetic event, which has foo and bar.

/sys/kernel/debug/tracing # cat synthetic_events 
testevent	int foo; int bar

And when I tried to add hist on trigger, both foo and bar can be used as below.

/sys/kernel/debug/tracing # echo "hist:keys=bar" > events/synthetic/testevent/trigger 
/sys/kernel/debug/tracing # echo "hist:keys=foo" > events/synthetic/testevent/trigger 

And, when I missed to specify the sort key, it failed

/sys/kernel/debug/tracing # echo "hist:keys=foo:sort=bar" > events/synthetic/testevent/trigger 
sh: write error: Invalid argument

But no error on error_log file.

/sys/kernel/debug/tracing # cat error_log 
/sys/kernel/debug/tracing #

Could you add some error message? What about below?

[ 5422.134656] hist:synthetic:testevent: error: Sort key must be one of keys.
  Command: keys=foo;sort=bar
                               ^

Thank you,


-- 
Masami Hiramatsu <mhiramat@kernel.org>