libc6-xen seems useless (for 3 independent reasons!)

[Loïc Minier]

Hi,

I tried installing libc6-xen on a hardy xen domU.

First, it's not picked up automatically; ldconfig -p reports no nosegneg dirs, so it's useless; if I create a /etc/ld.so.conf.d/xen.conf with "hwcap 1 nosegneg", these dirs appear in the "ldconfig -p" output.

Second, if I check with "ldd" on random binaries, the cmov version is preferred over the xen version when both are installed; this also renders the libc6-xen useless because libc6-i686 is always installed (dep of ubuntu-minimal) right now...

Finally, AFAICT, all i386 glibc passes are built with:
libc_extra_cflags = -mno-tls-direct-seg-refs
so if you compare i686 and xen passes:
i686_extra_cflags = -march=i686 -mtune=i686 -O3
xen_extra_cflags = -march=i686 -mtune=i686 -O3 -mno-tls-direct-seg-refs

it seems to me the xen pass is entirely useless as a result.

Perhaps it should be dropped?

Thanks,

[Loïc Minier (lool)]

I checked the Debian glibc packaging in SVN and it doesn't build with -mno-tls-direct-seg-refs by default and does ship a /etc/ld.so.conf.d/libc6-xen.conf in libc6-xen; I didn't check whether libc6-xen takes precedence over libc6-i686 on a Debian xen doMU though.