Jeremy Fitzhardinge wrote: > Add the "nosegneg" fake capabilty to the vsyscall page notes. This is > used by the runtime linker to select a glibc version which then > disables negative-offset accesses to the thread-local segment via > %gs. These accesses require emulation in Xen (because segments are > truncated to protect the hypervisor address space) and avoiding them > provides a measurable performance boost. > > Signed-off-by: Ian Pratt <ian.pratt at xensource.com> > Signed-off-by: Christian Limpach <Christian.Limpach at cl.cam.ac.uk> > Signed-off-by: Chris Wright <chrisw at sous-sol.org> > Acked-by: Zachary Amsden <zach at vmware.com> We would like to see this by dynamic, but that is much more difficult to achieve, and seeing your recent linker issues, I don't think this should gate merging this code. The performance loss for us I believe to be negligible, and the fix is quite a bit more complicated than something achievable in the .21 timeframe. Zach
