On Fri, Jul 1, 2011 at 6:10 PM, David Gilbert <david.gilb...@linaro.org> wrote: > Hi All, > I've just submitted the patches for the 64 bit atomic stuff to the > gcc-patches list. > Richard Henderson has raised the question of why the ARM commpage isn't a full > VDSO and, if it was, then it would make the version number check a lot > simpler. > > What's the history behind this/how big a job is it/
I think it's there partly for historical reasons, and partly because there has to be a page mapped somewhere for the exception vectors anyway, so we may as well put other snippets of required userspace code there. > Dave (on holiday for a week but checking mail intermittently) Because existing userspace source and binaries already call directly into the helper functions in the vectors page, we can't easily remove/move it. We could possibly wrap the vectors page to make it look like a DSO in a forwards-compatible way, but since this has not happened so far it feels like people never saw much benefit. Can you describe the benefits with regard to this case? (And, out of interest, how do statically-linked programs make use of needed functionality in the VDSO? Browsing the web hasn't revealed any coherent answers to that question for me...) Cheers ---Dave _______________________________________________ linaro-dev mailing list linaro-dev@lists.linaro.org http://lists.linaro.org/mailman/listinfo/linaro-dev
