Re: [PATCH 3/4] linux: Use /sys/devices/system/cpu/possible on __get_nprocs_conf

[Adhemerval Zanella <adhemerval.zanella@linaro.org>]

On 05/05/2021 15:06, Florian Weimer wrote:
> * Florian Weimer:
> 
>> * Adhemerval Zanella via Libc-alpha:
>>
>>> +      /* The entry is in the form of '[cpuX]-[cpuY]'.  */
>>> +      char buf[2 * INT_STRLEN_BOUND (unsigned int) + 1];
>>> +
>>> +      ssize_t n = __read_nocancel (fd, buf, sizeof (buf));
>>> +      if (n > 0)
>>> +	{
>>> +	  buf[n] = '\0';
>>> +
>>> +	  /* Start on the right, to find highest node number.  */
>>> +	  int m = 1;
>>> +	  while (--n)
>>> +	    {
>>> +	      if ((buf[n] == ',') || (buf[n] == '-'))
>>> +		break;
>>> +	      /* Ignore '\n'  */
>>> +	      if (! isdigit (buf[n]))
>>> +		continue;
>>> +	      result += (buf[n] - '0') * m;
>>> +	      m *= 10;
>>> +	    }
>>> +	}
>>> +
>>> +      __close_nocancel (fd);
>>> +      return result + 1;
>>>      }
>>
>> I think the /online and /possible files have the same layout, so you
>> could use both.
> 
> Sorry, I meant to write: “so you could use *one parser for* both”

I am not following, the second patch in this set *removed* the 
/sys/devices/system/cpu/online parsing in favor of the sched_getaffinity.
So now it only parses /sys/devices/system/cpu/possible and fallbacks
to sched_getaffinity.