FYI, we noticed the below changes on

https://git.linaro.org/people/dlezcano/linux chromebook2
commit b056c3f514313695e7a8eaf3beb1cbb4df3d37cf ("Store the next prediction for an irq")


+----------------------------------------------------------------+------------+------------+
|                                                                | 4c781d7747 | b056c3f514 |
+----------------------------------------------------------------+------------+------------+
| boot_successes                                                 | 15         | 5          |
| boot_failures                                                  | 5          | 15         |
| BUG:kernel_boot_hang                                           | 5          | 5          |
| BUG:sleeping_function_called_from_invalid_context_at_mm/slub.c | 0          | 10         |
| backtrace:ata_pci_sff_activate_host                            | 0          | 10         |
| backtrace:piix_init_one                                        | 0          | 10         |
| backtrace:__pci_register_driver                                | 0          | 10         |
| backtrace:piix_init                                            | 0          | 10         |
| backtrace:load_module                                          | 0          | 10         |
| backtrace:SyS_finit_module                                     | 0          | 10         |
+----------------------------------------------------------------+------------+------------+


[    5.288419] Error: Driver 'pcspkr' is already registered, aborting...
[    5.290145] Registered IRQ14 for timing measurements
[    5.290177] irqt: registered IRQ14
[    5.290178] BUG: sleeping function called from invalid context at mm/slub.c:1240
[    5.290179] in_atomic(): 1, irqs_disabled(): 1, pid: 244, name: modprobe
[    5.290180] CPU: 0 PID: 244 Comm: modprobe Not tainted 3.18.0-rc6-next-20141125-00101-g4002075 #5
[    5.290181] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[    5.290183]  00000000000004d8 ffff88003f0cb848 ffffffff8189bd9d 000000000d560d56
[    5.290184]  ffffffff81b7fa41 ffff88003f0cb858 ffffffff81098659 ffff88003f0cb888
[    5.290185]  ffffffff810986ca ffff88003f0cb878 000000000000000e ffff88003ece9700
[    5.290186] Call Trace:
[    5.290193]  [<ffffffff8189bd9d>] dump_stack+0x4c/0x65
[    5.290200]  [<ffffffff81098659>] ___might_sleep+0xd9/0x110
[    5.290201]  [<ffffffff810986ca>] __might_sleep+0x3a/0xd0
[    5.290203]  [<ffffffff811c66f7>] kmem_cache_alloc_trace+0x47/0x210
[    5.290207]  [<ffffffff810d41ec>] ? irqt_register+0x3c/0x70
[    5.290209]  [<ffffffff810d41ec>] irqt_register+0x3c/0x70
[    5.290211]  [<ffffffff810cf7ec>] __setup_irq+0x47c/0x650
[    5.290213]  [<ffffffff810cfae5>] ? request_threaded_irq+0x85/0x190
[    5.290220]  [<ffffffffa00c1d50>] ? ata_bmdma_port_intr+0x110/0x110 [libata]
[    5.290225]  [<ffffffffa00c1d50>] ? ata_bmdma_port_intr+0x110/0x110 [libata]
[    5.290227]  [<ffffffff810cfb2f>] request_threaded_irq+0xcf/0x190
[    5.290231]  [<ffffffffa00c1d50>] ? ata_bmdma_port_intr+0x110/0x110 [libata]
[    5.290232]  [<ffffffff810d19ff>] devm_request_threaded_irq+0x5f/0xc0
[    5.290236]  [<ffffffffa00c1d50>] ? ata_bmdma_port_intr+0x110/0x110 [libata]
[    5.290241]  [<ffffffffa00c0675>] ata_pci_sff_activate_host+0x115/0x230 [libata]
[    5.290243]  [<ffffffffa014a115>] piix_init_one+0x7c5/0x9cb [ata_piix]
[    5.290245]  [<ffffffff810986ca>] ? __might_sleep+0x3a/0xd0
[    5.290253]  [<ffffffff81443c65>] local_pci_probe+0x45/0xa0
[    5.290254]  [<ffffffff81444fd5>] ? pci_match_device+0xe5/0x110
[    5.290255]  [<ffffffff81445111>] pci_device_probe+0xd1/0x120
[    5.290258]  [<ffffffff81534160>] driver_probe_device+0x90/0x3e0
[    5.290259]  [<ffffffff8153458b>] __driver_attach+0x9b/0xa0
[    5.290260]  [<ffffffff815344f0>] ? __device_attach+0x40/0x40
[    5.290263]  [<ffffffff81531f3b>] bus_for_each_dev+0x6b/0xb0
[    5.290264]  [<ffffffff81533bde>] driver_attach+0x1e/0x20
[    5.290265]  [<ffffffff815337a0>] bus_add_driver+0x180/0x250
[    5.290266]  [<ffffffffa0153000>] ? 0xffffffffa0153000
[    5.290267]  [<ffffffff81534d94>] driver_register+0x64/0xf0
[    5.290268]  [<ffffffff814434bc>] __pci_register_driver+0x4c/0x50
[    5.290270]  [<ffffffffa015301e>] piix_init+0x1e/0x1000 [ata_piix]
[    5.290274]  [<ffffffff81002130>] do_one_initcall+0xc0/0x1f0
[    5.290278]  [<ffffffff811a97e2>] ? __vunmap+0xa2/0x100
[    5.290284]  [<ffffffff810faa74>] load_module+0x1444/0x1b20
[    5.290285]  [<ffffffff810f6500>] ? store_uevent+0x40/0x40
[    5.290287]  [<ffffffff810fb2f6>] SyS_finit_module+0x86/0xb0
[    5.290291]  [<ffffffff818a4469>] system_call_fastpath+0x12/0x17
[    5.290296] Registered IRQ15 for timing measurements
[    5.290321] irqt: registered IRQ15
[    5.304098] scsi host0: ata_piix



Thanks,
Fengguang