Comment 9 for bug 427288

Explanation of how the 'nosegneg' hwcap is supposed to work is found here:

http://lkml.org/lkml/2007/4/24/3

Upstream patch is here:

http://lkml.org/lkml/2007/4/23/339

From my testing, the linux-ec2 kernel does *not* set this hwcap in its vdso, therefore there's nothing to tell ld.so to use the nosegneg paths, regardless of whether /etc/ld.so.conf.d/ is configured correctly (which currently has to be done by hand; separate task will be opened).

The only reason the tested sequence had any effect at all was because libc6-i686 was removed from the system - even after doing this, the libc being used is the i486-optimized one in /lib, not the xen build in /lib/tls/i686/nosegneg. I'm hopeful that if we get nosegneg working, then there's no need to remove libc6-i686, so the image will work without penalty in both contexts.