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

[Florian Weimer <fweimer@redhat.com>]

* Adhemerval Zanella via Libc-alpha:

> 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.

Oh, right.  So you removed the old implementation and bring bug a
slightly different new one.  Got it.

Thanks,
Florian