| 76 | If you want to achive really low latency, you need to make sure that the interrupt line (IRQ) for the IEEE 1394 port is not shared with another device under high load. To check this, do |
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| 77 | {{{ |
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| 78 | $ cat /proc/interrupts |
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| 79 | CPU0 |
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| 80 | 0: 1459348 IO-APIC-edge timer |
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| 81 | 1: 32119 IO-APIC-edge i8042 |
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| 82 | 8: 1 IO-APIC-edge rtc0 |
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| 83 | 9: 420 IO-APIC-fasteoi acpi |
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| 84 | 12: 357681 IO-APIC-edge i8042 |
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| 85 | 14: 378389 IO-APIC-edge ata_piix |
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| 86 | 15: 0 IO-APIC-edge ata_piix |
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| 87 | 16: 3606467 IO-APIC-fasteoi uhci_hcd:usb1, yenta, i915@pci:0000:00:02.0, eth0, ohci1394 |
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| 88 | 17: 710 IO-APIC-fasteoi uhci_hcd:usb2, mmc0 |
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| 89 | 18: 426 IO-APIC-fasteoi uhci_hcd:usb3 |
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| 90 | 19: 11119 IO-APIC-fasteoi uhci_hcd:usb4, ehci_hcd:usb5 |
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| 91 | 21: 203452 IO-APIC-fasteoi ipw2200 |
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| 92 | 22: 262623 IO-APIC-fasteoi Intel ICH6 |
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| 93 | 23: 0 IO-APIC-fasteoi Intel ICH6 Modem |
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| 94 | NMI: 0 Non-maskable interrupts |
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| 95 | LOC: 1457733 Local timer interrupts |
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| 96 | RES: 0 Rescheduling interrupts |
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| 97 | CAL: 0 function call interrupts |
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| 98 | TLB: 0 TLB shootdowns |
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| 99 | TRM: 0 Thermal event interrupts |
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| 100 | SPU: 0 Spurious interrupts |
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| 101 | ERR: 0 |
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| 102 | MIS: 0 |
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| 103 | }}} |
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| 104 | The relevant line is the one containing the "ohci1394" driver. '''FIXME:''' ''What other modules are there? Does this apply to the new firewire stack as well?'' |
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