2019-06-20 12:18:37

by Masami Hiramatsu

Subject: No invalid histogram error

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 <[email protected]>

2019-06-20 14:48:26

by Tom Zanussi

Subject: Re: No invalid histogram error

Hi Masami,

On 6/20/2019 7:17 AM, Masami Hiramatsu wrote:
> 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
> ^


Sure, I'll submit a fix for this.  Thanks for pointing it out.


Tom


> Thank you,
>
>