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我有一個內核模塊。它有一個IOCTL，它分配頁面，然後使用kmap_atomic一次一頁地映射到內核。在進程上下文中調用kmap_atomic（）
當我運行通過一個測試應用程序行使這種IOCTL，我得到以下調度BUG：
[41216.007065] BUG: scheduling while atomic: app/1242/0x00000002
[41216.007403] Modules linked in: allocator(O) gpu(O) [last unloaded: gpu]
[41216.007910] CPU: 0 PID: 1242 Comm: app Tainted: G W O 4.10.0-rc5-00111-g49e555a-dirty #22
[41216.008385] Hardware name: linux,dummy-virt (DT)
[41216.008667] Call trace:
[41216.008907] [<ffff000008088ba0>] dump_backtrace+0x0/0x23c
[41216.009242] [<ffff000008088df0>] show_stack+0x14/0x1c
[41216.009563] [<ffff000008375efc>] dump_stack+0x94/0xb4
[41216.010318] [<ffff00000816bcb0>] __schedule_bug+0x58/0x6c
[41216.010723] [<ffff0000088a9204>] __schedule+0x404/0x574
[41216.011099] [<ffff0000088a93ac>] schedule+0x38/0x9c
[41216.011454] [<ffff00000808873c>] do_notify_resume+0x90/0xa0
[41216.011844] [<ffff000008083618>] work_pending+0x8/0x10
有誰知道是什麼原因造成的？ 在內核中，該消息被印刷在內核/排程/ core.c 因爲下面的檢查爲真
if (unlikely(in_atomic_preempt_off())) {
__schedule_bug(prev);
preempt_count_set(PREEMPT_DISABLED);
}
該檢查在定義包括/ LINUX/preempt.h
/*
* Check whether we were atomic before we did preempt_disable():
* (used by the scheduler)
*/
#define in_atomic_preempt_off() (preempt_count() != PREEMPT_DISABLE_OFFSET)
如果這對任何人都有意義，請分享你的觀點。