[LTP] Question about kernel/syscall/signal/signal06.c

[Cyril Hrubis]

Hi!
> I find signal06 fails on qemux86-64 when qemu has a small number cores, 
> e.g. "qemu -smp 1/2/4/6".
> 
> ERROR INFO:
> 
> signal06?????? 0?? TINFO?? :?? loop = 23
> signal06?????? 1?? TFAIL?? :?? signal06.c:87: Bug Reproduced!
> 
> But if boot qemu with "-smp 16", the case has great chance to pass.
> 
> 
> I have two questions about this case:
> 
> 1. I don't know why multi-core will affect the case.

Have you looked into the code? The test is trying to reproduce a race
condition between two threads of course the number of cores does affect
the reproducibility.

> 2. On failure situation, what does break the "while loop" shown in below 
> code.

Bug in a kernel that fails to restore fpu state.

-- 
Cyril Hrubis
chrubis@suse.cz