[Buildroot] [PATCH] glibc: remove version 2.21

[Gustavo Zacarias <gustavo@zacarias.com.ar>]

On 22/02/16 09:33, Thomas Petazzoni wrote:

> I don't really see why you're talking specifically about atomics here,
> but OK with the rest.

Because newer glibc versions need them for thread barriers, see glibc 
source in sysdeps/sparc/sparc32/atomic-machine.h

>> So basically yes, sparc = no glibc, sparc64 = yes glibc, because we
>> don't support multilib (in gentoo it wasn't 100% multilib in the past,
>> except that binutils/gcc did support -m64/-m32, but there wasn't libc
>> support, hence not really multilib).
>
> I don't follow the relation with multilib support. Care to expand on
> this?

Since you can't build a 32-bit linux kernel for v9+ then you need a gcc 
capable of -m64 for v9, even if your userland is 32-bit.
There's no separation in cpu mode for SPARC 32/64 bits like there is for 
x86, so you can use the new instructions even in 32-bit "mode".
Regards.