Dipankar Sarma a écrit :
> On Fri, Mar 20, 2009 at 06:28:11AM +0100, Eric Dumazet wrote:
>> Paul E. McKenney a écrit :
>> Hmm... point is to make linux boot as fast as possible, so ...
>>
>> Use a special variant of udelay() in offending drivers that make appropriate
>> RCU call to increment quiescent state ?
>
> It may not be safe to do this it is in a RCU read-side critical section.
Yes, this is why I suggested a variant of udelay, not udelay() itself,
used by selected drivers (probably not so many drivers hog cpu so long)
void udelay_rcu_quiescent(unsigned long usecs)
{
preempt_disable();
rcu_qsctr_inc(smp_processor_id());
preempt_enable();
udelay(usecs);
}
Or maybe we have a way to detect we are in a RCU-side critical section at runtime ?
void __udelay(unsigned long usecs)
{
if (!in_rcu_critical_section()) {
preempt_disable();
rcu_qsctr_inc(smp_processor_id());
preempt_enable();
}
...
}
Thank you
--
To unsubscribe from this list: send the line "unsubscribe linux-input" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
