[Bug middle-end/24644] [4.1 Regression] gcc-4.1 compiled ppc64 kernels do not boot

[olh at suse dot de]

------- Comment #4 from olh at suse dot de  2005-11-03 12:58 -------
What I have found so far with even more debugging:

<4>Processor 1 found.
<7>schedule(2883) swapper(0):c1,j4294892318 c0000000142ae100
<6>Brought up 2 CPUs
<7>_spin_lock_irq(85) swapper(0):c1,j4294892318 l c0000000142ae100 c
c0000000004db98c
<7>schedule(2996) swapper(0):c1,j4294892318 p c00000000ffd7040 n
c00000000ffd2040 r c0000000142ae100
<7>schedule(3002) swapper(0):c1,j4294892318 p c00000000ffd7040 n
c00000000ffd2040 r c0000000142ae100
<7>schedule(3029) swapper(1):c0,j4294892318 p c00000000ffd7040 n
c00000000ffd7810 r c0000000142a6100 t c0000000142a6100
<7>finish_task_switch(1539) swapper(1):c0,j4294892318 r c0000000142a6100 p
c00000000ffd7040
<7>finish_lock_switch(297) swapper(1):c0,j4294892318
<7>_spin_unlock_irq(292) migration/1(5):c1,j4294892318 l c0000000142a6100 c
c0000000004dbd24
<4>BUG: spinlock already unlocked on CPU#1, migration/1/5

schedule() line 2883 grabs the rq at c0000000142ae100 on cpu1, and calls
spinlock.
later in line 3029, it switches to cpu0 and rq becomes c0000000142a6100, 
this is after context_switch(), barrier(), finish_task_switch(),
finish_lock_switch()
For some reason, the _spin_unlock_irq() call from finish_lock_switch() happens
on cpu1?
But this should be no real problem, the real thing is, why changed rq 
from c0000000142ae100 to c0000000142a6100 between lines 3002 and 3029.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24644