Xen - nosegneg broken on hardy
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
linux (Ubuntu) |
New
|
Undecided
|
Unassigned |
Bug Description
Binary package hint: linux-image-
Error occurs on:
Ubuntu 8.0.4.1 (Server installation CD with online updates)
After freshly installing Hardy and switching to the xen kernel (install ubuntu-xen-server) the wrong tls libraries are used. The following warning is displayed during boot:
*******
*******
** WARNING: Currently emulating unsupported memory accesses **
** in /lib/tls glibc libraries. The emulation is **
** slow. To ensure full performance you should **
** install a 'xen-friendly' (nosegneg) version of **
** the library, or disable tls support by executing **
** the following as root: **
** mv /lib/tls /lib/tls.disabled **
** Offending process: init (pid=2710) **
*******
*******
ldd /bin/bash also show that the cmov variant of the libc is used, not the nosegneg.
Moving /lib/tls to /lib/tls.disabled fixes the warning, but this is prone to break again by installing updates.
The correct solution would be to use the nosegneg version of libc.
libc6-xen is installed and the neccessary libraries are in /lib/tls/
Creating the missing file with the content "hwcap 1 nosegneg" and running ldconfig doesn't help. (Note: On Ubunto 7.10 the file had to read "hwcap 0 nosegneg" The flag has been changed to 1. This is documented in the kernel sources: linux-2.
Installing linux-image-
ldd /bin/bash prove that the nosegneg libraries are now prefered.
Therfore I assume the linker itself is ok and the hwcap flag must be missing in the kernel. Unfortunatelly I'm unable to find an way to display the hwcap flags from the running kernel.
# uname -a
Linux Xen 2.6.24-19-xen #1 SMP Sat Jul 12 03:55:08 UTC 2008 i686 GNU/Linux
# cat /proc/version_
Ubuntu 2.6.24-4.6-generic
The Ubuntu Kernel Team is planning to move to the 2.6.27 kernel for the upcoming Intrepid Ibex 8.10 release. As a result, the kernel team would appreciate it if you could please test this newer 2.6.27 Ubuntu kernel. There are one of two ways you should be able to test:
1) If you are comfortable installing packages on your own, the linux-image- 2.6.27- * package is currently available for you to install and test.
--or--
2) The upcoming Alpha5 for Intrepid Ibex 8.10 will contain this newer 2.6.27 Ubuntu kernel. Alpha5 is set to be released Thursday Sept 4. Please watch http:// www.ubuntu. com/testing for Alpha5 to be announced. You should then be able to test via a LiveCD.
Please let us know immediately if this newer 2.6.27 kernel resolves the bug reported here or if the issue remains. More importantly, please open a new bug report for each new bug/regression introduced by the 2.6.27 kernel and tag the bug report with 'linux-2.6.27'. Also, please specifically note if the issue does or does not appear in the 2.6.26 kernel. Thanks again, we really appreicate your help and feedback.