Comment 15 for bug 427288

I've just tested on ami-a40fefcd , which uses the kernel in question that installing libc6-xen fixes this problem in ec2.

I booted the instance, then 'apt-get update && apt-get install libc6-xen'. After a reboot, I have:

$ uname -r
2.6.31-300-ec2
$ dpkg -l "libc6*" | grep ^ii
ii libc6 2.10.1-0ubuntu11 GNU C Library: Shared libraries
ii libc6-i686 2.10.1-0ubuntu11 GNU C Library: Shared libraries [i686 optimi
ii libc6-xen 2.10.1-0ubuntu11 GNU C Library: Shared libraries [Xen version
$ ldd /bin/bash
        linux-gate.so.1 => (0xb7ef6000)
        libncurses.so.5 => /lib/libncurses.so.5 (0xb7eb5000)
        libdl.so.2 => /lib/libdl.so.2 (0xb7eb1000)
        libc.so.6 => /lib/libc.so.6 (0xb7d54000)
        /lib/ld-linux.so.2 (0xb7ef7000)
$ dmesg | grep "\*\*.*WARN" || echo "no warnings"
no warnings
$ time perl -e 'glob("xxx*")'
real 0m0.007s
user 0m0.000s
sys 0m0.000s

Steve successfully debugged that /etc/ld.so.nohwcap existed and was causing the problems. After removal of that file and 'ldconfig', a ldd /bin/bash will show 'libc.so.6 => /lib/tls/i686/nosegneg/libc.so.6'