On Thu, Nov 1, 2012 at 2:01 PM, Ian Lepore <free...@damnhippie.dyndns.org> wrote: > On Thu, 2012-11-01 at 10:42 +0000, Attilio Rao wrote: >> On 11/1/12, Gleb Smirnoff <gleb...@freebsd.org> wrote: >> > On Wed, Oct 31, 2012 at 06:33:51PM +0000, Attilio Rao wrote: >> > A> > Doesn't this padding to cache line size only help x86 processors in an >> > A> > SMP kernel? I was expecting to see some #ifdef SMP so that we don't >> > pay >> > A> > a big price for no gain in small-memory ARM systems and such. But >> > maybe >> > A> > I'm misunderstanding the reason for the padding. >> > A> >> > A> I didn't want to do this because this would be meaning that SMP option >> > A> may become a completely killer for modules/kernel ABI compatibility. >> > >> > Do we support loading non-SMP modules on SMP kernel and vice versa? >> >> Actually that's my point, we do. >> >> Attilio >> >> > > Well we've got other similar problems lurking then. What about a module > compiled on an arm system that had #define CACHE_LINE_SIZE 32 and then > it gets run on a different arm system whose kernel is compiled with > #define CACHE_LINE_SIZE 64?
That should not happen. Is that a real case where you build a module for an ARM family and want to run against a kernel compiled for another? CACHE_LINE_SIZE must not change during a STABLE release lifetime, of course, for the same arch. Attilio -- Peace can only be achieved by understanding - A. Einstein _______________________________________________ svn-src-head@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
