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SubjectRe: [PATCH] rwlock_is_locked undefined for UP systems
ok....I understand that rwlock_is_locked( ) is to be protected by
CONFIG_SMP. But I was tempted when I saw spin_is_locked( )
to be returning zero for !SMP in include/linux/spinlock.h .
Am I seeing something wrong here?

Christoph Hellwig wrote:

>On Fri, Jan 16, 2004 at 07:15:11PM +0530, Prashanth T wrote:
>
>
>>Hi,
>> I had to use rwlock_is_locked( ) with linux2.6 for kdb and noticed that
>>this routine to be undefined for UP. I have attached the patch for 2.6.1
>>below to return 0 for rwlock_is_locked( ) on UP systems.
>>Please let me know.
>>
>>
>
>we don't implement spin_is_locked on UP either because there's no really
>usefull return value. The lock will never be taken on !SMP && !PREEMPT,
>but OTOH it's also not needed, so any assert on will give false results.
>And the assert is probably the only thing that the _is_locked routines
>could used for sanely.
>
>
>
>

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