Re: [PATCH v8 03/13] perf evlist: implement control command handling functions

Alexey Budankov
2020-06-24T13:35:07Z

On 23.06.2020 18:14, Jiri Olsa wrote:
> On Tue, Jun 23, 2020 at 12:03:45PM -0300, Arnaldo Carvalho de Melo wrote:
>> Em Tue, Jun 23, 2020 at 04:56:01PM +0200, Jiri Olsa escreveu:
>>> On Wed, Jun 17, 2020 at 11:36:46AM +0300, Alexey Budankov wrote:
>>>
>>> SNIP
>>>
>>>> + memset(cmd_data, 0, data_size--);
>>>> +
>>>> + do {
>>>> + err = read(evlist->ctl_fd.fd, &c, 1);
>>>> + if (err > 0) {
>>>> + if (c == '\n' || c == '\0')
>>>> + break;
>>>> + cmd_data[bytes_read++] = c;
>>>> + if (bytes_read == data_size)
>>>> + break;
>>>> + } else {
>>>> + if (err == -1)
>>>> + pr_err("Failed to read from ctlfd %d: %m\n", evlist->ctl_fd.fd);
>>>> + break;
>>>> + }
>>>> + } while (1);
>>>> +
>>>> + pr_debug("Message from ctl_fd: \"%s%s\"\n", cmd_data,
>>>> + bytes_read == data_size ? "" : c == '\n' ? "\\n" : "\\0");
>>>> +
>>>> + if (err > 0) {
>>>> + if (!strncmp(cmd_data, EVLIST_CTL_CMD_ENABLE_TAG,
>>>> + strlen(EVLIST_CTL_CMD_ENABLE_TAG))) {
>>>
>>> you could use sizeof(EVLIST_CTL_CMD_ENABLE_TAG) instead, no function call
>>
>> -1, as sizeof will get the \0, right?
>
> yep, I think that's right

Ok, let's have it like (sizeof(EVLIST_CTL_CMD_ENABLE_TAG)-1).

~Alexey

>
> jirka
>
>>
>>>
>>>> + *cmd = EVLIST_CTL_CMD_ENABLE;
>>>> + } else if (!strncmp(cmd_data, EVLIST_CTL_CMD_DISABLE_TAG,
>>>> + strlen(EVLIST_CTL_CMD_DISABLE_TAG))) {
>>>
>>> ditto
>>>
>>> jirka
>>>
>>
>> --
>>
>> - Arnaldo
>>
>