Messages in this thread | | | Date | Sat, 28 Oct 2006 12:42:45 -0700 | From | thockin@hockin ... | Subject | Re: AMD X2 unsynced TSC fix? |
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On Sat, Oct 28, 2006 at 09:32:18PM +0200, Willy Tarreau wrote: > > Was the problem that they were not synced at poweron or that they would > > drift due to power-states? > > They resynced at power up, but would constantly drift. I don't even know > if it was caused by power states. When the machine was loaded, a single > task moving across the cores could see its time jump back and forth > several times a second by an offset sometimes close to +2/-2s.
That sounds like C1, to me.
> > Did you try running with idle=poll, to avoid ever entering C1 state (hlt)? > > Yes, I remember trying such things. I also tried 'nohlt', completely > disabling power management, including ACPI, etc... I also tried vanilla > kernels as well as severely patched ones, but the problem remained the > same in all circumstances, that only 'notsc' could solve.
That's exceedingly strange. On my dual-socket dual-core, I can get roughly synced TSCs (no appreciable drift) by just using idle=poll. If that did not work for you, I'd really want to poke at the system more.
> BTW, I've just found a remain of dmesg capture after boot in case you'd > like to look for anything in it.
A dmesg won't be that useful, I'd actually have to poke at the system. - 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/
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