Messages in this thread | | | Subject | Re: CONFIG_NO_HZ: missed ticks, stall (keyb IRQ required) [2.6.18-rc4-mm1] | From | Thomas Gleixner <> | Date | Tue, 07 Nov 2006 10:28:57 +0100 |
| |
On Tue, 2006-11-07 at 10:16 +0100, Andreas Mohr wrote: > Hi, > > On Tue, Nov 07, 2006 at 09:25:35AM +0100, Thomas Gleixner wrote: > > Andreas tested with the latest -mm1-hrt-dyntick patches, so he has all > > the checks already. The thing which worries me here is, that we detect > > the breakage and use the fallback path already, but it still has this > > weird effect on that system, while others just work fine. I'm cooking a > > more brute force fallback right now. > > That's what I didn't understand all that time: > I do get the "C2 unusable, kills APIC timer" message, so I expected the code > to not use C2, but it seems it did use it (causing hangs) and I didn't > fully analyze the code whether it truly tried to prevent C2 here > (handling was a bit opaque to me, should have analyzed it > more thoroughly to get to know exactly what happens). > > And like I said, brutally hard-wiring max_cstate to C1 already fixed > dynticks things for me, so it seems as if it still touched C2 before.
Yes, it leaves the C states untouched, it uses (should use) PIT instead of the local APIC timer. I'm a bit confused, why this does not work on your box.
tglx
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |