Re: [PATCH 1/1] glibc: Allow 64 bit atomics for x86

[Richard Purdie <richard.purdie@linuxfoundation.org>]

On Thu, 2015-10-29 at 15:29 -0700, Randy Witt wrote:
> 
> 
> On Thu, Oct 29, 2015 at 3:20 PM, Richard Purdie
> <richard.purdie@linuxfoundation.org> wrote:
>         On Thu, 2015-10-29 at 13:43 -0700, Juro Bystricky wrote:
>         > This patch fixes [YOCTO#8140].
>         >
>         > The fix consist of allowing 64bit atomic ops for x86.
>         > This should be safe for i586 and newer CPUs.
>         > It also makes the synchronization more efficient.
>         >
>         > Signed-off-by: Juro Bystricky <juro.bystricky@intel.com>
>         > ---
>         >  .../glibc/glibc/use_64bit_atomics.patch            | 24
>         ++++++++++++++++++++++
>         >  meta/recipes-core/glibc/glibc_2.22.bb              |  1 +
>         >  2 files changed, 25 insertions(+)
>         >  create mode 100644
>         meta/recipes-core/glibc/glibc/use_64bit_atomics.patch
>         
>         Since the patch is only changing nativesdk 32 bit x86 and we
>         know that
>         the 32 bit SDK is pretty broken at the moment I've merged this
>         on the
>         basis that it can't really make it any worse. There is
>         pressure to move
>         to the next rc candidate for 2.0.
>         
>         I would like to get to the bottom of the real issue here and I
>         still
>         suspect 32 bit x86 images are likely broken too :/.
>
>
> With Juro's change I built core-image-minimal using a 32-bit
> buildtools on a 32-bit host(vm) and that appears to boot fine using
> runqemu.

Right, but can we run bitbake in a qemux86 image (on target) or does it
show the same issue as bug 8140? If it shows the same issue, futexes are
likely bust on 32 bit x86 targets too.

Cheers,

Richard