On Wed, Nov 16, 2011 at 9:16 AM, Keith Packard <keithp at keithp.com> wrote: > On Wed, 16 Nov 2011 16:49:40 +0100, Daniel Vetter <daniel.vetter at ffwll.ch> wrote: > >> So we need to check whether DMAR is enabled (on the >> entire system, i.e. the variable exported for the ilk workaround is >> not good enough) > > Can you figure out what *would* be sufficient? Getting semaphores turned > on for the 99% who aren't enabling VT-d would be a fairly nice > performance improvement. AFAICT my snb laptop has always been stable with semaphores and VT-d enabled. Is this problem possibly restricted to just desktop machines? I'm happy to test, since my box that can reproduce the hang instantly is still around. Also, rc6-by-default would be very nice. It decreases the total power consumption on my laptop from over 13W to around 8W. That's huge. --Andy
