Hello,
I have a hard time making the 2.6-test11 to work correctly.
I constantly get messages about irq 18.
The kernel boots, linux works, but I get such messages every second :

Dec  7 18:28:24 pici kernel: irq 18: nobody cared!
Dec  7 18:28:24 pici kernel: Call Trace:
Dec  7 18:28:24 pici kernel:  [<c010b08b>] __report_bad_irq+0x2b/0x90
Dec  7 18:28:24 pici kernel:  [<c010b093>] __report_bad_irq+0x33/0x90
Dec  7 18:28:24 pici kernel:  [<c010b168>] note_interrupt+0x50/0x78
Dec  7 18:28:24 pici kernel:  [<c010b3f7>] do_IRQ+0xf7/0x180
Dec  7 18:28:24 pici kernel:  [<c0105000>] _stext+0x0/0x60
Dec  7 18:28:24 pici kernel:  [<c0109aec>] common_interrupt+0x18/0x20
Dec  7 18:28:24 pici kernel:  [<c0105000>] _stext+0x0/0x60
Dec  7 18:28:24 pici kernel:  [<c0107010>] default_idle+0x2c/0x34
Dec  7 18:28:24 pici kernel:  [<c01070a6>] cpu_idle+0x3a/0x48
Dec  7 18:28:24 pici kernel:  [<c0105057>] _stext+0x57/0x60
Dec  7 18:28:24 pici kernel:  [<c03aa7f3>] start_kernel+0x16b/0x174
Dec  7 18:28:24 pici kernel:
Dec  7 18:28:24 pici kernel: handlers:
Dec  7 18:28:24 pici kernel: [<c0221364>] (ide_intr+0x0/0x1b4)
Dec  7 18:28:24 pici kernel: [<c0221364>] (ide_intr+0x0/0x1b4)
Dec  7 18:28:24 pici kernel: Disabling IRQ #18

I also had this :
Dec  7 18:27:45 pici kernel: hdg: dma_timer_expiry: dma status == 0x24
Dec  7 18:27:45 pici kernel: hdg: DMA interrupt recovery
Dec  7 18:27:45 pici kernel: hdg: lost interrupt
Dec  7 18:27:45 pici kernel: irq 18: nobody cared!
Dec  7 18:27:45 pici kernel: Call Trace:
Dec  7 18:27:45 pici kernel:  [<c010b08b>] __report_bad_irq+0x2b/0x90
Dec  7 18:27:45 pici kernel:  [<c010b093>] __report_bad_irq+0x33/0x90
Dec  7 18:27:45 pici kernel:  [<c010b168>] note_interrupt+0x50/0x78
Dec  7 18:27:45 pici kernel:  [<c010b3f7>] do_IRQ+0xf7/0x180
Dec  7 18:27:45 pici kernel:  [<c0109aec>] common_interrupt+0x18/0x20
Dec  7 18:27:45 pici kernel:  [<c01222b1>] do_softirq+0x61/0xd0
Dec  7 18:27:45 pici kernel:  [<c010b466>] do_IRQ+0x166/0x180
Dec  7 18:27:45 pici kernel:  [<c0109aec>] common_interrupt+0x18/0x20
Dec  7 18:27:45 pici kernel:  [<c022007b>] ide_complete_pm_request+0x9b/0xe0
Dec  7 18:27:45 pici kernel:  [<c021048f>] generic_unplug_device+0x73/0x8c
Dec  7 18:27:45 pici kernel:  [<c0210619>] blk_run_queues+0x9d/0xe4
Dec  7 18:27:45 pici kernel:  [<c01520ba>] __wait_on_buffer+0x92/0xb4
Dec  7 18:27:45 pici kernel:  [<c011c680>] autoremove_wake_function+0x0/0x3c
Dec  7 18:27:45 pici kernel:  [<c011c680>] autoremove_wake_function+0x0/0x3c
Dec  7 18:27:45 pici kernel:  [<c01540ef>] __block_prepare_write+0x2a3/0x398
Dec  7 18:27:45 pici kernel:  [<c0154904>] block_prepare_write+0x20/0x3c
Dec  7 18:27:45 pici kernel:  [<c019d2b8>] ext2_get_block+0x0/0x3b4
Dec  7 18:27:45 pici kernel:  [<c019d6d9>] ext2_prepare_write+0x19/0x20
Dec  7 18:27:45 pici kernel:  [<c019d2b8>] ext2_get_block+0x0/0x3b4
Dec  7 18:27:45 pici kernel:  [<c013800e>] generic_file_aio_write_nolock+0x6ba/0xa9c
Dec  7 18:27:45 pici kernel:  [<c0143b8b>] do_anonymous_page+0x22f/0x23c
Dec  7 18:27:45 pici kernel:  [<c013845f>] generic_file_write_nolock+0x6f/0x8c
Dec  7 18:27:45 pici kernel:  [<c0117cf5>] do_page_fault+0x15d/0x4aa
Dec  7 18:27:45 pici kernel:  [<c0117b98>] do_page_fault+0x0/0x4aa
Dec  7 18:27:45 pici kernel:  [<c013856f>] generic_file_write+0x57/0x70
Dec  7 18:27:45 pici kernel:  [<c0150fee>] vfs_write+0x9e/0xd0
Dec  7 18:27:45 pici kernel:  [<c01510a0>] sys_write+0x30/0x50
Dec  7 18:27:45 pici kernel:  [<c010917f>] syscall_call+0x7/0xb
Dec  7 18:27:45 pici kernel:
Dec  7 18:27:45 pici kernel: handlers:
Dec  7 18:27:45 pici kernel: [<c0221364>] (ide_intr+0x0/0x1b4)
Dec  7 18:27:45 pici kernel: [<c0221364>] (ide_intr+0x0/0x1b4)
Dec  7 18:27:45 pici kernel: Disabling IRQ #18

I am using a P4 2.6 Ghz without HT activated
512 MB DDR PC3200 on an ASUS P4P800 Deluxe MB.
HardDrive is on SATA (native mode) : Maxtor 6Y120MO.

2.4.23 doesn't have this problem but keeps using 30-50% CPU even if I do nothing.
Attached is attached grep "=[y|m]" .config

Regards,
Raphaël RIGO