On Mon, Nov 19, 2012 at 02:48:06PM +0000, Russell King - ARM Linux wrote: > On Mon, Nov 19, 2012 at 04:32:36PM +0200, Ville Syrjälä wrote: > > On Thu, Nov 15, 2012 at 02:39:41PM +0000, Arnd Bergmann wrote: > > > On Thursday 15 November 2012, Rob Clark wrote: > > > > > I still haven't heard a conclusive argument why we need to use get_user() > > > > > rather than copy_from_user() in the DRM code. Is this about a fast path > > > > > where you want to shave off a few cycles for each call, or does this > > > > > simplify the code structure, or something else? > > > > > > > > well, it is mostly because it seemed like a good idea to first try to > > > > solve the root issue, rather than having to fix things up in each > > > > driver when someone from x86-world introduces a 64b get_user().. > > > > > > As pointed out by hpa earlier, x86-32 doesn't have a 64b get_user > > > either. I don't think we have a lot of drivers that are used only > > > on 64-bit x86 and on 32-bit ARM but not on 32-bit x86. > > > > Ouch. I didn't realize that x86-32 doesn't have it. All the systems > > where I've run the new code are 64bit so I never noticed the problem. > > > > I see there was a patch [1] posted a long time ago to implement 64bit > > get_user() on x86-32. I wonder what happened to it? > > > > [1] https://lkml.org/lkml/2004/4/20/96 > > Wonderful lkml.org after four "Negotiating SSL connection..." messages > gives me under elinks... <snip> > what a wonderful site... please choose another LKML archive, preferably > one which works. Thanks. This one look like the same thing: http://article.gmane.org/gmane.linux.kernel/198823 -- Ville Syrjälä Intel OTC _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
