Re: [PATCH 2/2] perf timechart: Remove open-coded event parsing code

[Li Zefan <lizf@cn.fujitsu.com>]

Arjan van de Ven wrote:
> On Tue, 01 Dec 2009 14:05:16 +0800
> Li Zefan <lizf@cn.fujitsu.com> wrote:
>> -		size = 8;
>> +	if (!(sample_type & PERF_SAMPLE_RAW)) {
>> +		fprintf(stderr,
>> +			"No trace sample to read. Did you call perf
>> record "
>> +			"without -R?");
>> +		return -1;
>>  	}
> 
> while I like your cleanup... I am not so sure this printk makes sense
> whatsoever.... the user did not use "perf record" to get here...
> 

I followed builtin-trace.c and builtin-sched.c.

Well, if you run perf-record without -R, like:

 # ./perf record -a -R -f -e power:* -e sched:sched_wakeup -e sched:sched_switch

And then run perf-timechart, you'll run into that warning.

But sure, if we always run "perf timechart rec" before "perf timechart",
we never get there.