According to /proc/interrupts, every interrupt received by eth1 is also being received by the sound card EMU10K1. The problem showed itself first with this. The sound system was quiet BTW.
It does not happen with 2.6.24 vanilla. kernel: irq 19: nobody cared (try booting with the "irqpoll" option) kernel: Pid: 1832, comm: IRQ-19 Not tainted 2.6.24.2-crt #2 kernel: [<c013d6da>] __report_bad_irq+0x36/0x75 kernel: [<c013d910>] note_interrupt+0x1f7/0x227 kernel: [<c013ce85>] thread_simple_irq+0x61/0x74 kernel: [<c013d455>] do_irqd+0x0/0x22f kernel: [<c013d507>] do_irqd+0xb2/0x22f kernel: [<c013d455>] do_irqd+0x0/0x22f kernel: [<c012b137>] kthread+0x38/0x5d kernel: [<c012b0ff>] kthread+0x0/0x5d kernel: [<c0104c13>] kernel_thread_helper+0x7/0x10 kernel: ======================= kernel: --------------------------- kernel: | preempt count: 00000001 ] kernel: | 1-level deep critical section nesting: kernel: ---------------------------------------- kernel: .. [<c02b03b3>] .... __spin_lock_irq+0xe/0x1e kernel: .....[<00000000>] .. ( <= _stext+0x3feff000/0x14) kernel: kernel: handlers: kernel: [<f4d16544>] (snd_emu10k1_interrupt+0x0/0x42c [snd_emu10k1]) kernel: turning off IO-APIC fast mode. kernel: irq 19: nobody cared (try booting with the "irqpoll" option) kernel: Pid: 1832, comm: IRQ-19 Not tainted 2.6.24.2-crt #2 kernel: [<c013d6da>] __report_bad_irq+0x36/0x75 kernel: [<c013d910>] note_interrupt+0x1f7/0x227 kernel: [<c013ce85>] thread_simple_irq+0x61/0x74 kernel: [<c013d455>] do_irqd+0x0/0x22f kernel: [<c013d507>] do_irqd+0xb2/0x22f kernel: [<c013d455>] do_irqd+0x0/0x22f kernel: [<c012b137>] kthread+0x38/0x5d kernel: [<c012b0ff>] kthread+0x0/0x5d kernel: [<c0104c13>] kernel_thread_helper+0x7/0x10 kernel: ======================= kernel: --------------------------- kernel: | preempt count: 00000001 ] kernel: | 1-level deep critical section nesting: kernel: ---------------------------------------- kernel: .. [<c02b03b3>] .... __spin_lock_irq+0xe/0x1e kernel: .....[<00000000>] .. ( <= _stext+0x3feff000/0x14) kernel: kernel: handlers: kernel: [<f4d16544>] (snd_emu10k1_interrupt+0x0/0x42c [snd_emu10k1]) Looking at /proc/interrupts I could see the the EMU10K1 interrupt was going to town. I was busy busy on eth1 at the time. So a simple externall ping test with a quiet system at run level-3 revealed: # lspci cat before.ping CPU0 CPU1 0: 85 0 IO-APIC-edge timer 1: 396 420 IO-APIC-edge i8042 3: 4 2 IO-APIC-edge 4: 5 1 IO-APIC-edge 6: 1 4 IO-APIC-edge floppy 7: 0 0 IO-APIC-edge parport0 8: 2 0 IO-APIC-edge rtc 9: 0 1 IO-APIC-fasteoi acpi 12: 21 84 IO-APIC-edge i8042 14: 8457 8179 IO-APIC-edge libata 15: 1016 1519 IO-APIC-edge libata 16: 60 60 IO-APIC-fasteoi aic7xxx 17: 113 96 IO-APIC-fasteoi eth1 18: 44 47 IO-APIC-fasteoi 19: 99 114 IO-APIC-fasteoi EMU10K1 NMI: 0 0 Non-maskable interrupts LOC: 93895 94157 Local timer interrupts RES: 8831 8188 Rescheduling interrupts CAL: 4176 5267 function call interrupts TLB: 271 235 TLB shootdowns TRM: 0 0 Thermal event interrupts SPU: 0 0 Spurious interrupts ERR: 0 MIS: 0 Then from an external machine: ping -c10 10.10.10.200 # cat after.ping CPU0 CPU1 0: 85 0 IO-APIC-edge timer 1: 464 432 IO-APIC-edge i8042 3: 4 2 IO-APIC-edge 4: 5 1 IO-APIC-edge 6: 1 4 IO-APIC-edge floppy 7: 0 0 IO-APIC-edge parport0 8: 2 0 IO-APIC-edge rtc 9: 0 1 IO-APIC-fasteoi acpi 12: 21 84 IO-APIC-edge i8042 14: 8460 8198 IO-APIC-edge libata 15: 1360 1549 IO-APIC-edge libata 16: 60 60 IO-APIC-fasteoi aic7xxx 17: 129 102 IO-APIC-fasteoi eth1 18: 44 47 IO-APIC-fasteoi 19: 105 130 IO-APIC-fasteoi EMU10K1 NMI: 0 0 Non-maskable interrupts LOC: 104387 104637 Local timer interrupts RES: 8890 8214 Rescheduling interrupts CAL: 4176 5267 function call interrupts TLB: 271 236 TLB shootdowns TRM: 0 0 Thermal event interrupts SPU: 0 0 Spurious interrupts ERR: 0 MIS: 0 44 interrupts added to both eth1 and EMU10K1 #lspci 00:00.0 Host bridge: Advanced Micro Devices [AMD] AMD-760 MP [IGD4-2P] System Controller (rev 20) 00:01.0 PCI bridge: Advanced Micro Devices [AMD] AMD-760 MP [IGD4-2P] AGP Bridge 00:07.0 ISA bridge: Advanced Micro Devices [AMD] AMD-768 [Opus] ISA (rev 05) 00:07.1 IDE interface: Advanced Micro Devices [AMD] AMD-768 [Opus] IDE (rev 04) 00:07.3 Bridge: Advanced Micro Devices [AMD] AMD-768 [Opus] ACPI (rev 03) 00:08.0 Ethernet controller: 3Com Corporation 3c905C-TX/TX-M [Tornado] (rev 6c) 00:09.0 Class Class ff00: Compro Computer Services, Inc. Unknown device 4610 (rev 03) 00:10.0 PCI bridge: Advanced Micro Devices [AMD] AMD-768 [Opus] PCI (rev 05) 01:05.0 VGA compatible controller: nVidia Corporation NV25 [GeForce4 Ti 4400] (rev a2) 02:04.0 Multimedia audio controller: Creative Labs SB Live! EMU10k1 (rev 04) 02:04.1 Input device controller: Creative Labs SB Live! Game Port (rev 01) 02:05.0 Communication controller: National Instruments PCI-GPIB (rev 01) 02:06.0 SCSI storage controller: Adaptec AHA-2930CU (rev 03) 02:07.0 Communication controller: National Instruments PCI-GPIB (rev 01) 02:08.0 Ethernet controller: 3Com Corporation 3c905C-TX/TX-M [Tornado] (rev 78) Again this does not happen with 2.6.24 vanilla. I'm not sure about earlier RT kernels. Regards Mark -- 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/