Re: [PATCH v1 2/2] perf-stat: enable counting events for BPF programs

[Song Liu]

> On Dec 3, 2020, at 3:31 PM, Jiri Olsa <jolsa@xxxxxxxxxx> wrote:
> 
> On Wed, Dec 02, 2020 at 01:37:09AM -0800, Song Liu wrote:
>> Introduce perf-stat -b option, which counts events for BPF programs, like:
>> 
>> [root@localhost ~]# ~/perf stat -e ref-cycles,cycles -b 254 -I 1000
>>     1.487903822            115,200      ref-cycles
>>     1.487903822             86,012      cycles
>>     2.489147029             80,560      ref-cycles
>>     2.489147029             73,784      cycles
>>     3.490341825             60,720      ref-cycles
>>     3.490341825             37,797      cycles
>>     4.491540887             37,120      ref-cycles
>>     4.491540887             31,963      cycles
> 
> hi,
> I'm getting compile fail with gcc 10:
> 
> 	builtin-stat.c: In function ‘cmd_stat’:
> 	builtin-stat.c:2429:7: error: declaration of ‘err’ shadows a previous local [-Werror=shadow]
> 	 2429 |   int err = perf_event__synthesize_kernel_mmap((void *)&perf_stat,
> 	      |       ^~~
> 	builtin-stat.c:2104:33: note: shadowed declaration is here
> 	 2104 |  int status = -EINVAL, run_idx, err;
> 	      |                                 ^~~

gcc 9 didn't complain about it. Let me fix it in the next version. 

Thanks,
Song