On Wed, Apr 06, 2005 at 07:44:12AM +0200, Ingo Molnar wrote: > > * Nick Piggin <[EMAIL PROTECTED]> wrote: > > > This is Suresh's patch with some modifications. > > > Remove degenerate scheduler domains during the sched-domain init. > > actually, i'd suggest to not do this patch. The point of booting with a > CONFIG_NUMA kernel on a non-NUMA box is mostly for testing, and the
Not really. All of the x86_64 kernels are NUMA enabled and most Intel x86_64 systems today are non NUMA. > 'degenerate' toplevel domain exposed conceptual bugs in the > sched-domains code. In that sense removing such 'unnecessary' domains > inhibits debuggability to a certain degree. If we had this patch earlier > we'd not have experienced the wrong decisions taken by the scheduler, > only on the much rarer 'really NUMA' boxes. > > is there any case where we'd want to simplify the domain tree? One more > domain level is just one (and very minor) aspect of CONFIG_NUMA - i'd > not want to run a CONFIG_NUMA kernel on a non-NUMA box, even if the > domain tree got optimized. Hm? > Ingo, pardon me! Actually I used NUMA domain as an excuse to push domain degenerate patch.... As I mentioned earlier, we should remove SMT domain on a non-HT capable system. Similarly I am working on adding a new core domain for dual-core systems! All these domains are unnecessary and cause performance isssues on non Multi-threading/Multi-core capable cpus! Agreed that performance impact will be minor but still... thanks, suresh - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/