Vivek Goyal <[EMAIL PROTECTED]> writes: > On Thu, Dec 06, 2007 at 04:39:51PM -0500, Neil Horman wrote: >> On Fri, Nov 30, 2007 at 09:51:31AM -0500, Neil Horman wrote: >> > On Fri, Nov 30, 2007 at 09:42:50AM -0500, Vivek Goyal wrote: >> <snip> >> > >> > Thats what I'm doing at the moment. I'm working on a RHEL5 patch at the > moment >> > (since thats whats on the production system thats failing), and will >> > forward >> > port it once its working >> > >> > And not to split hairs, but techically thats not our _only_ choice. We > could >> > force kdump boots on cpu0 as well ;) >> > >> > Thanks >> > Neil >> > >> > > Thanks >> > > Vivek >> > >> >> >> Sorry to have been quiet on this issue for a few days. Interesting news to >> report, though. So I was working on a patch to do early apic enabling on >> x86_64, and had something working for the old 2.6.18 kernel that we were >> origionally testing on. Unfortunately while it worked on 2.6.18 it failed >> miserably on 2.6.24-rc3-mm2, causing check_timer to consistently report that > the >> timer interrupt wasn't getting received (even though we could successfully >> run >> calibrate_delay). Vivek and I were digging into this, when I ran accross the >> description of the hypertransport configuration register in the opteron >> specification. It contains a bit that, suprise, configures the ht bus to > either >> unicast interrupts delivered accross the ht bus to a single cpu, or to > broadcast >> it to all cpus. Since it seemed more likely that the 8259 in the nvidia >> southbridge was transporting legacy mode interrupts over the ht bus than >> directly to cpu0 via an actual wire, I wrote the attached patch to add a >> quirk >> for nvidia chipsets, which scanned for hypertransport controllers, and >> ensured >> that that broadcast bit was set. Test results indicate that this solves the >> problem, and kdump kernels boot just fine on the affected system. >> > > Hi Neil, > > Should we disable this broadcasting feature once we are through? Otherwise > in normal systems it might mean extra traffic on hypertransport. There > is no need for every interrupt to be broadcasted in normal systems?
My feel is that if it is for legacy interrupts only it should not be a problem. Let's investigate and see if we can unconditionally enable this quirk for all opteron systems. Eric -- 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/
