Re: 2.5.38-mm2 [PATCH]

On Mon, Sep 23, 2002 at 09:28:41AM -0700, Andrew Morton wrote:

#ifdef CONFIG_PREEMPTION
#define rcu_read_lock()        preempt_disable()
#define rcu_read_unlock()      preempt_enable()
#else
#define rcu_read_lock()        do {} while(0)
#define rcu_read_unlock()      do {} while(0)
#endif

with

#define rcu_read_lock()        preempt_disable()
#define rcu_read_unlock()      preempt_enable()

because preempt_disable() is a no-op on CONFIG_PREEMPT=n anyway.

This is fine. The original rcu_ltimer patch needed #ifdef CONFIG_PREEMPT,
so that it could be easily used with 2.4. With preemption in 2.5, 
rcu_read_xxx() can be preempt_xxx().

Thanks
-- 
Dipankar Sarma  [off-list ref] http://lse.sourceforge.net
Linux Technology Center, IBM Software Lab, Bangalore, India.
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/