Re: [PATCH v7 03/13] perf evlist: implement control command handling functions

[Alexey Budankov]

On 23.06.2020 17:54, Jiri Olsa wrote:
> On Wed, Jun 03, 2020 at 06:54:47PM +0300, Alexey Budankov wrote:
> 
> SNIP
> 
>> +			case EVLIST_CTL_CMD_ACK:
>> +			case EVLIST_CTL_CMD_UNSUPPORTED:
>> +			default:
>> +				pr_debug("ctlfd: unsupported %d\n", *cmd);
>> +				break;
>> +			}
>> +			if (!(*cmd == EVLIST_CTL_CMD_ACK || *cmd == EVLIST_CTL_CMD_UNSUPPORTED))
>> +				evlist__ctlfd_ack(evlist);
>> +		}
>> +	}
>> +
>> +	if (stat_entries[ctlfd_pos].revents & (POLLHUP | POLLERR))
>> +		evlist__finalize_ctlfd(evlist);
>> +	else
>> +		stat_entries[ctlfd_pos].revents = 0;
>> +
>> +	return err;
>> +}
>> diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
>> index 0d8b361f1c8e..bccf0a970371 100644
>> --- a/tools/perf/util/evlist.h
>> +++ b/tools/perf/util/evlist.h
>> @@ -360,4 +360,21 @@ void perf_evlist__force_leader(struct evlist *evlist);
>>  struct evsel *perf_evlist__reset_weak_group(struct evlist *evlist,
>>  						 struct evsel *evsel,
>>  						bool close);
>> +#define EVLIST_CTL_CMD_ENABLE_TAG  "enable"
>> +#define EVLIST_CTL_CMD_DISABLE_TAG "disable"
>> +#define EVLIST_CTL_CMD_ACK_TAG     "ack\n"
> 
> why the \n at the end of ack?

This \n stops reading by read command from within shell script.
\n can be avoided in ack if using "read -n 3 -u $fd res" instead
of just "read -u $fd res" by the script.

~Alexey

> 
> jirka
>