Re: [patch] Add a writer prior lock methord for rwlock

[Liu Tao <liutao@safe-mail.net>]

Arjan van de Ven wrote:

>On Wed, 2004-08-04 at 11:09, Liu Tao wrote:
>  
>
>>The patch adds the write_forcelock() methord, which has higher priority than
>>read_lock() and write_lock(). The original read_lock() and write_lock() 
>>is not
>>touched, and the unlock methord is still write_unlock();
>>The patch gives implemention on i386, for kernel 2.6.7.
>>    
>>
>
>can you please elaborate what kind of usage scenarios this would be
>useful ? It would be nice to know what this is for ;)
>  
>

write_forcelock() should be used to avoid readers starve writers, or for 
writers
to update shared data as far as possiable, since it prevents new readers 
acquire
the lock while it's waiting for existing readers release their locks. 
I'm not clear
who will need it now,  since it doesn't affect the original read_lock() 
and write_lock()
I tried it.

Regards