Linux kernel stacks. CFS scheduler deques a task .

A set of call stacks when a scheduler switches task. The related kernel source is Quark X1000 Linux kernel

Stack 1:

#0  __dequeue_entity (se=0xce2edfac, cfs_rq=0xc14d4700 <runqueues+64>) at kernel/sched/fair.c:531
#1  set_next_entity (cfs_rq=cfs_rq@entry=0xc14d4700 <runqueues+64>, se=se@entry=0xce2edfac) at kernel/sched/fair.c:1868
#2  pick_next_task_fair (rq=0xc14d46c0 <runqueues>) at kernel/sched/fair.c:3608
#3  pick_next_task (rq=0xc14d46c0 <runqueues>) at kernel/sched/core.c:2832
#4  __schedule () at kernel/sched/core.c:2934
#5  schedule () at kernel/sched/core.c:2979
#6  cpu_idle () at arch/x86/kernel/process.c:367
#7  rest_init () at init/main.c:385
#8  start_kernel () at init/main.c:643
#9  i386_start_kernel () at arch/x86/kernel/head32.c:66


Stack 2:

#0  __dequeue_entity (se=0xc00623fc, cfs_rq=0xc14d4700 <runqueues+64>) at kernel/sched/fair.c:531
#1  set_next_entity (cfs_rq=cfs_rq@entry=0xc14d4700 <runqueues+64>, se=se@entry=0xc00623fc) at kernel/sched/fair.c:1868
#2  pick_next_task_fair (rq=0xc14d46c0 <runqueues>) at kernel/sched/fair.c:3608
#3  pick_next_task (rq=0xc14d46c0 <runqueues>) at kernel/sched/core.c:2832
#4  __schedule () at kernel/sched/core.c:2934
#5  schedule () at kernel/sched/core.c:2979
#6  schedule_hrtimeout_range_clock (expires=expires@entry=0xce30ff7c, delta=delta@entry=999997, 
    mode=mode@entry=HRTIMER_MODE_ABS, clock=clock@entry=1) at kernel/hrtimer.c:1809
#7  schedule_hrtimeout_range (expires=expires@entry=0xce30ff7c, delta=delta@entry=999997, mode=mode@entry=HRTIMER_MODE_ABS)
    at kernel/hrtimer.c:1850
#8  ep_poll (timeout=1000, maxevents=<optimised out>, events=0x97062b8, ep=<optimised out>) at fs/eventpoll.c:1546
#9  sys_epoll_wait (epfd=6, events=0x97062b8, maxevents=1025, timeout=1000) at fs/eventpoll.c:1892
#10 <signal handler called>

Stack 3:

#0  __dequeue_entity (se=0xce288c1c, cfs_rq=0xc14d4700 <runqueues+64>) at kernel/sched/fair.c:531
#1  set_next_entity (cfs_rq=cfs_rq@entry=0xc14d4700 <runqueues+64>, se=se@entry=0xce288c1c) at kernel/sched/fair.c:1868
#2  pick_next_task_fair (rq=0xc14d46c0 <runqueues>) at kernel/sched/fair.c:3608
#3  pick_next_task (rq=0xc14d46c0 <runqueues>) at kernel/sched/core.c:2832
#4  __schedule () at kernel/sched/core.c:2934
#5  schedule () at kernel/sched/core.c:2979
#6  worker_thread (__worker=0xcc4f9c40) at kernel/workqueue.c:2407
#7  kthread (_create=0xcea53ec4) at kernel/kthread.c:168
#8  ret_from_kernel_thread () at arch/x86/kernel/entry_32.S:311
#9  ?? () at kernel/kthread.c:420

Stack 4:

#0  __dequeue_entity (se=0xce9f3bdc, cfs_rq=0xc14d4700 <runqueues+64>) at kernel/sched/fair.c:531

#1  set_next_entity (cfs_rq=cfs_rq@entry=0xc14d4700 <runqueues+64>, se=se@entry=0xce9f3bdc) at kernel/sched/fair.c:1868

#2  pick_next_task_fair (rq=0xc14d46c0 <runqueues>) at kernel/sched/fair.c:3608

#3  pick_next_task (rq=0xc14d46c0 <runqueues>) at kernel/sched/core.c:2832

#4  __schedule () at kernel/sched/core.c:2934

#5  schedule () at kernel/sched/core.c:2979

#6  futex_wait_queue_me (hb=<optimised out>, q=q@entry=0xce183e6c, timeout=timeout@entry=0xce183ea4) at kernel/futex.c:1808

#7  futex_wait (uaddr=uaddr@entry=0x807f524, flags=flags@entry=2, val=val@entry=4733, abs_time=abs_time@entry=0xce183f98, 

    bitset=4294967295) at kernel/futex.c:1923

#8  do_futex (uaddr=uaddr@entry=0x807f524, op=op@entry=393, val=val@entry=4733, timeout=0xce183f98, 

    uaddr2=uaddr2@entry=0x807f550, val2=0, val3=<optimised out>, val3@entry=4294967295) at kernel/futex.c:2669

#9  sys_futex (uaddr=0x807f524, op=393, val=4733, utime=0x8081d5c, uaddr2=0x807f550, val3=4294967295) at kernel/futex.c:2727

#10 <signal handler called>