On Mon, 2013-06-17 at 19:22 -0500, Scott Wood wrote: > On 06/17/2013 07:17:30 PM, Benjamin Herrenschmidt wrote: > > On Mon, 2013-06-17 at 19:01 -0500, Scott Wood wrote: > > > I really doubt the exception scratch registers need to be saved -- > > > we're not trying to restore into the middle of an exception > > > prolog/epilog. > > > > > > book3s has the PACA as well and they don't save it. Don't we rely > > on > > > things like boot-time memory allocations happening in the same place > > > when we resume? extlb is part of the PACA, so the same applies. > > > > I doubt we seriously tested hibernation :-) The PACA SPR should > > definitely be saved/restored. > > OK. It's not obvious to me how much the entire mechanism depends on > things like boot time allocations being the same each time -- if we do > depend on that in general, then the PACA shouldn't change on a > particular CPU, right?
No we shouldn't be depending on that stuff. > Is it possible to restore on a different CPU than we saved on? If so, > could restoring the PACA leave us pointing to a different CPU's PACA? Today on your code no, but of course this needs to be handled, the PACA should be restored along with other thing, but for the right processor :-) Cheers, Ben. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
