[PATCH] powerpc: New feature - HWCAP/HWCAP2 bits in the TCB

[Steve Munroe]

Mike Frysinger <vapier@gentoo.org> wrote on 07/08/2015 12:42:25 PM:

> From: Mike Frysinger <vapier@gentoo.org>
> To: Carlos Eduardo Seo <cseo@linux.vnet.ibm.com>
> Cc: GLIBC Devel <libc-alpha@sourceware.org>, Steve
Munroe/Rochester/IBM@IBMUS
> Date: 07/08/2015 12:42 PM
> Subject: Re: [PATCH] powerpc: New feature - HWCAP/HWCAP2 bits in the TCB
>
> On 08 Jul 2015 10:55, Carlos Eduardo Seo wrote:
> > tcb-offsets.h is generated from tcb-offsets.sym during the glibc
> build and isn’t installed. That’s why the offsets are duplicated in
> ppc.h, which is a public header.
>
> then perhaps tcb-offsets.h or something like it should be installed
alongside
> the ppc.h header ?

I fear that what you propose would just ignite another endless debate about
the wisdom of exposing the TCB and struct pthreads to users.

The current ./sysdeps/powerpc/nptl/tcb-offsets.sym includes offsets for
header.multiple_threads, header.private_futex, and pointer_guard which I
suspect the community feels (and I agree) are private to GLIBC
implementation.

So for now I would like to just provide nice #defines for the two fields
evolved and then once the community considers and agrees to a general
policy we can work on a more general solution.

I would like to catch the 2.22 train before it leaves.

Ok?


Steven J. Munroe
Linux on Power Toolchain Architect
IBM Corporation, Linux Technology Center