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Date: Tue, 14 Apr 2020 18:55:06 +0200
From: Florian Weimer <>
To: Rich Felker <>
Cc:,  Norbert Lange <>
Subject: Re: [BUG] sysconf implementing _SC_NPROCESSORS_(CONF|ONLN) incorrectly

* Rich Felker:

> On Tue, Apr 14, 2020 at 12:08:52PM +0200, Florian Weimer wrote:
>> * Rich Felker:
>> >> For glibc, we had to change our logic to artificially inflate the CPU
>> >> to 2 if we cannot determine it, as the more conservative choice.
>> >
>> > Wait, you mean some software is abusing these interfaces to omit
>> > memory barriers or something? *facepalm* *sigh*
>> Yes, indeed.  glibc itself parses uname -v output for this purpose
>> (something we should probably remove, too).
> I don't understand. Certainly it's not executing a child process at
> runtime. Do you mean SYS_uname or are you talking about guessing
> number of cpus for parallel build at make time or something?

I meant the string that is printed by uname -v.  The internal
implementation is of course different.

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