Messages in this thread | | | From | Con Kolivas <> | Subject | Re: [ck] [PATCH] dynamic-tick patch modified for SMP | Date | Tue, 16 Aug 2005 02:30:51 +1000 |
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On Tue, 16 Aug 2005 01:35, Srivatsa Vaddagiri wrote: > On Sun, Aug 14, 2005 at 10:18:28AM +1000, Con Kolivas wrote: > > timers that made no progress until interrupts drove the timers on again. > > I built in both PIT and APIC dyntick mode into the kernel and the default > > in the way I modified the patch is for APIC mode to be used if it's built > > in. After that I modified the values using the sysfs interface at > > /sys/devices/system/dyn_tick/dyn_tick0/. In APIC mode it seems to run > > close to > > Con, > I am observing the reverse problem - my patch does not work in APIC > mode. I am thinking it has to do something with disabling PIT interrupts. > > Have you enabled CONFIG_DYN_TICK_USE_APIC in my patch?
yes I already said I tried apic mode, that's the one that works "best" but I suspect that's reflecting the fact that I hardly ever go below 300Hz on this machine except in init 1. Time definitely was lost the longer the machine was running.
> What does > /sys/.../dyn_tick0/state show when my patch is working (in APIC mode for > you)?
suitable: 1 enabled: 1 apic suitable: 1 using APIC: 1 (remember I wrote the sysfs portion ;) )
> Can you disable CONFIG_DYN_TICK_USE_APIC with my patch and check if > it works?
You mean disable it at runtime or not compile it in at all? Disabling it at runtime caused what I described to you as PIT mode (long stalls etc).
> Also can you send me 'dmesg | grep APIC' (want to know if your > hardware has local APIC that is enabled by the kernel).
ACPI: Local APIC address 0xfee00000 ACPI: LAPIC (acpi_id[0x00] lapic_id[0x00] enabled) Processor #0 15:2 APIC version 20 ACPI: LAPIC (acpi_id[0x01] lapic_id[0x01] enabled) Processor #1 15:2 APIC version 20 ACPI: LAPIC_NMI (acpi_id[0x00] high edge lint[0x1]) ACPI: LAPIC_NMI (acpi_id[0x01] high edge lint[0x1]) ACPI: IOAPIC (id[0x02] address[0xfec00000] gsi_base[0]) IOAPIC[0]: apic_id 2, version 32, address 0xfec00000, GSI 0-23 Enabling APIC mode: Flat. Using 1 I/O APICs mapped APIC to ffffd000 (fee00000) mapped IOAPIC to ffffc000 (fec00000) ENABLING IO-APIC IRQs ACPI: Using IOAPIC for interrupt routing
Cheers, Con - 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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