FYI, we noticed the below changes on

git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
commit 8eb23b9f35aae413140d3fda766a98092c21e9b0 ("sched: Debug nested sleeps")


+-------------------------------------------------+------------+------------+
|                                                 | 26cabd3125 | 8eb23b9f35 |
+-------------------------------------------------+------------+------------+
| boot_successes                                  | 10         | 15         |
| boot_failures                                   | 0          | 25         |
| WARNING:at_kernel/sched/core.c:__might_sleep()  | 0          | 5          |
| backtrace:SyS_read                              | 0          | 5          |
| backtrace:vfs_read                              | 0          | 5          |
| WARNING:at_kernel/sched/core.c:#__might_sleep() | 0          | 20         |
| backtrace:SyS_io_getevents                      | 0          | 10         |
| backtrace:read_events                           | 0          | 7          |
| backtrace:kauditd_thread                        | 0          | 10         |
+-------------------------------------------------+------------+------------+



<4>[  839.494114] ------------[ cut here ]------------
<4>[  839.494131] WARNING: CPU: 0 PID: 13608 at /kbuild/src/lkp/kernel/sched/core.c:7323 __might_sleep+0xbd/0xd0()
<4>[  839.494137] do not call blocking ops when !TASK_RUNNING; state=1 set at [<ffffffff810b3fff>] prepare_to_wait+0x2f/0x90
<4>[  839.494256] Modules linked in: tun ipmi_watchdog loop btrfs xor raid6_pq sg sd_mod ast snd_pcm syscopyarea sysfillrect snd_timer sysimgblt snd ie6xx_wdt ttm i2c_isch drm_kms_helper soundcore drm ahci libahci pcspkr i2c_ismt lpc_sch ipmi_si libata shpchp ipmi_msghandler acpi_cpufreq
<4>[  839.494264] CPU: 0 PID: 13608 Comm: fanotify01 Not tainted 3.18.0-rc4-next-20141117 #1
<4>[  839.494266] Hardware name: To be filled by O.E.M. To be filled by O.E.M./Double Cove , BIOS BWDEXT.86B.000.012.D127 10/08/2012
<4>[  839.494273]  ffffffff81b5ebb8 ffff88023cf37d18 ffffffff81892f54 0000000064026402
<4>[  839.494277]  ffff88023cf37d68 ffff88023cf37d58 ffffffff8107047a ffff88023cf37db8
<4>[  839.494281]  ffffffff81b5f5e8 0000000000000061 0000000000000000 0000000000006000
<4>[  839.494285] Call Trace:
<4>[  839.494315]  [<ffffffff81892f54>] dump_stack+0x4c/0x65
<4>[  839.494323]  [<ffffffff8107047a>] warn_slowpath_common+0x8a/0xc0
<4>[  839.494327]  [<ffffffff810704f6>] warn_slowpath_fmt+0x46/0x50
<4>[  839.494333]  [<ffffffff810b3fff>] ? prepare_to_wait+0x2f/0x90
<4>[  839.494337]  [<ffffffff810b3fff>] ? prepare_to_wait+0x2f/0x90
<4>[  839.494341]  [<ffffffff810961fd>] __might_sleep+0xbd/0xd0
<4>[  839.494348]  [<ffffffff81898974>] mutex_lock+0x24/0x50
<4>[  839.494354]  [<ffffffff812250f5>] fanotify_read+0xd5/0x620
<4>[  839.494370]  [<ffffffff8139c906>] ? selinux_file_permission+0xa6/0x120
<4>[  839.494374]  [<ffffffff810b43e0>] ? wait_woken+0xc0/0xc0
<4>[  839.494381]  [<ffffffff811e14c8>] __vfs_read+0x18/0x50
<4>[  839.494385]  [<ffffffff811e158a>] vfs_read+0x8a/0x140
<4>[  839.494390]  [<ffffffff811e1686>] SyS_read+0x46/0xb0
<4>[  839.494403]  [<ffffffff8189b629>] system_call_fastpath+0x12/0x17
<4>[  839.494409] ---[ end trace 5a2207521429f889 ]---



	--yliu