i''m using xen 3.1 and i have a 64bit dom0 and 32bit (PAE enabled) domUs (32bit userland and kernels). Do I still need to replace glibc w/ one compiled with -mno-tls-refs in the domUs? I don''t get the warning about glibc during the domU boots. -- --- Joseph Smith smithj@iivip.com _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
> i''m using xen 3.1 and i have a 64bit dom0 and 32bit (PAE enabled) domUs > (32bit userland and kernels). Do I still need to replace glibc w/ one > compiled with -mno-tls-refs in the domUs? I don''t get the warning about > glibc during the domU boots.No, you don''t need to do that. The TLS refs problem happened because 32-bit Xen and glibc both want to do crazy things with the processor''s segmentation hardware. 32-bit Xen needs the segmentation for its own protection. 64-bit Xen doesn''t protect itself using segmentation, so it''s not necessary to do anything to prevent a conflict with glibc. Enjoy! Cheers, Mark -- Dave: Just a question. What use is a unicyle with no seat? And no pedals! Mark: To answer a question with a question: What use is a skateboard? Dave: Skateboards have wheels. Mark: My wheel has a wheel! _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Mark Williamson wrote:>> i''m using xen 3.1 and i have a 64bit dom0 and 32bit (PAE enabled) domUs >> (32bit userland and kernels). Do I still need to replace glibc w/ one >> compiled with -mno-tls-refs in the domUs? I don''t get the warning about >> glibc during the domU boots. >> > > No, you don''t need to do that. > > The TLS refs problem happened because 32-bit Xen and glibc both want to do > crazy things with the processor''s segmentation hardware. 32-bit Xen needs > the segmentation for its own protection. > > 64-bit Xen doesn''t protect itself using segmentation, so it''s not necessary to > do anything to prevent a conflict with glibc. >That old problem also seemed to involve the libraries in /lib/tls. It was easy to just move them aside to /lib/tls.old, and current versions of RedHat kernels drop a little file called "kernelcap" in /etc/ld.so.conf.d/ that helps prevent the use of those libraries. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
> > The TLS refs problem happened because 32-bit Xen and glibc both want to > > do crazy things with the processor''s segmentation hardware. 32-bit Xen > > needs the segmentation for its own protection. > > > > 64-bit Xen doesn''t protect itself using segmentation, so it''s not > > necessary to do anything to prevent a conflict with glibc. > > That old problem also seemed to involve the libraries in /lib/tls. It > was easy to just move them aside to /lib/tls.old, and current versions > of RedHat kernels drop a little file called "kernelcap" in > /etc/ld.so.conf.d/ that helps prevent the use of those libraries.Yes, recent Xen-friendly distributions don''t need the TLS libraries to be manually disabled because they handle it themselves in an appropriate way - even on 32-bit Xen. But this isn''t necessary on 64-bit, so glibc is free to use segments in funny ways (which I think is intended to produce a performance benefit, but from what I''ve heard it''s doubtful whether you''ll actually notice it). Cheers, Mark -- Dave: Just a question. What use is a unicyle with no seat? And no pedals! Mark: To answer a question with a question: What use is a skateboard? Dave: Skateboards have wheels. Mark: My wheel has a wheel! _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users