I have set up Debian lenny domains using debootstrap (similar to the tutorial on http://www.option-c.com/xwiki/Create_a_Debian_VM_with_debootstrap). As most tutorials say, /lib/tls should be renamed to /lib/tls.disabled - but that file doesn''t even exist on Lenny?! Anyway, this shouldn''t be a problem because I installed libc6-xen on the guest domain, but I still get this warning: *************************************************************** *************************************************************** ** 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=701) ** *************************************************************** *************************************************************** I guess the init process is statically linked against a normal xen-unfriendly libc?? If yes, how do I replace it with a xen-friendly init and does that prevent my dom0 mouse cursor from stuttering when I start/shutdown domains (i.e. is there a performance difference ;-) ? Best regards _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Rob, This is a neat fix for this problem with RHEL/Centos, might work with Debian (?): create a file called /etc/ld.so.conf.d/nosegneg.conf that contains this: # This directive teaches ldconfig to search in nosegneg subdirectories # and cache the DSOs there with extra bit 0 set in their hwcap match # fields. In Xen guest kernels, the vDSO tells the dynamic linker to # search in nosegneg subdirectories and to match this extra hwcap bit # in the ld.so.cache file. hwcap 0 nosegneg ldconfig Rob From: xen-users-bounces@lists.xensource.com [mailto:xen-users-bounces@lists.xensource.com] On Behalf Of Andreas Sommer Sent: 21 August 2009 09:52 To: Xen-users@lists.xensource.com Subject: [Xen-users] Debian lenny and the TLS warning I have set up Debian lenny domains using debootstrap (similar to the tutorial on http://www.option-c.com/xwiki/Create_a_Debian_VM_with_debootstrap). As most tutorials say, /lib/tls should be renamed to /lib/tls.disabled - but that file doesn''t even exist on Lenny?! Anyway, this shouldn''t be a problem because I installed libc6-xen on the guest domain, but I still get this warning: *************************************************************** *************************************************************** ** 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=701) ** *************************************************************** *************************************************************** I guess the init process is statically linked against a normal xen-unfriendly libc?? If yes, how do I replace it with a xen-friendly init and does that prevent my dom0 mouse cursor from stuttering when I start/shutdown domains (i.e. is there a performance difference ;-) ? Best regards The SAQ Group Registered Office: 18 Chapel Street, Petersfield, Hampshire GU32 3DZ SAQ is the trading name of SEMTEC Limited. Registered in England & Wales Company Number: 06481952 http://www.saqnet.co.uk AS29219 SAQ Group Delivers high quality, honestly priced communication and I.T. services to UK Business. Broadband : Domains : Email : Hosting : CoLo : Servers : Racks : Transit : Backups : Managed Networks : Remote Support. ISPA Member _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
The nosegneg setting is only valid for dynamically linked programs, I guess. It is automatically restored to "1" (probably by libc6-xen) when rebooting the domain. You''re right, it does not make a difference with the init process. Robert Dunkley wrote:> > Hi Andreas, > > > > Sorry ignore my last reply, I just noticed the offending process is > different. > > > > Rob > > ------------------------------------------------------------------------ > > This is a neat fix for this problem with RHEL/Centos, might work with > Debian (?): > > > > create a file called /etc/ld.so.conf.d/nosegneg.conf that contains this: > > > > # This directive teaches ldconfig to search in nosegneg subdirectories > > # and cache the DSOs there with extra bit 0 set in their hwcap match > > # fields. In Xen guest kernels, the vDSO tells the dynamic linker to > > # search in nosegneg subdirectories and to match this extra hwcap bit > > # in the ld.so.cache file. > > hwcap 0 nosegneg > > > > ldconfig > > > > Rob > > > > > *From:* xen-users-bounces@lists.xensource.com > [mailto:xen-users-bounces@lists.xensource.com] *On Behalf Of *Andreas > Sommer > *Sent:* 21 August 2009 09:52 > *To:* Xen-users@lists.xensource.com > *Subject:* [Xen-users] Debian lenny and the TLS warning > > > > I have set up Debian lenny domains using debootstrap (similar to the > tutorial on > http://www.option-c.com/xwiki/Create_a_Debian_VM_with_debootstrap). As > most tutorials say, /lib/tls should be renamed to /lib/tls.disabled - > but that file doesn''t even exist on Lenny?! Anyway, this shouldn''t be > a problem because I installed libc6-xen on the guest domain, but I > still get this warning: > > *************************************************************** > *************************************************************** > ** 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=701) ** > *************************************************************** > *************************************************************** > > I guess the init process is statically linked against a normal > xen-unfriendly libc?? If yes, how do I replace it with a xen-friendly > init and does that prevent my dom0 mouse cursor from stuttering when I > start/shutdown domains (i.e. is there a performance difference ;-) ? > > Best regards > > ** > > *The SAQ Group* > > *Registered Office: 18 Chapel Street, Petersfield, Hampshire GU32 3DZ* > SAQ is the trading name of SEMTEC Limited. Registered in England & Wales > Company Number: 06481952 > > > > http://www.saqnet.co.uk <http://www.saqnet.co.uk/> AS29219 > > SAQ Group Delivers high quality, honestly priced communication and > I.T. services to UK Business. > > Broadband : Domains : Email : Hosting : CoLo : Servers : Racks : > Transit : Backups : Managed Networks : Remote Support. > > > > SAQ Group > > > > *ISPA Member* >_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users