On 9/19/07, Peter Zijlstra <[EMAIL PROTECTED]> wrote: > On Wed, 19 Sep 2007 14:49:56 -0400 "Dmitry Torokhov" > <[EMAIL PROTECTED]> wrote: > > > On 9/19/07, Paul E. McKenney <[EMAIL PROTECTED]> wrote: > > > > PS to previous -- any problem with inserting rcu_read_lock() and > > > rcu_read_unlock() around the portion of the IRQ handler that has > > > these accesses? > > > > > > > I guess I could but it is an extra lock that needs to be managed and > > given the fact that it is not really needed (other to make a newly > > developed tool happy) I am hestsant to do that. > > As is, these sites are a bug in -rt and we'll need to fix them anyway. > > As for the code you pointed me to, the i8042 driver, it seems to play > way to funny tricks for a simple 'slow' driver.
Even "slow" driver should try not to slow down the rest of the system if it can help it. I am sorry if the thing it does do not quite fit in with the changes you are proposing but it does not make the exeisting code invalid. > > If you replace the spin_lock() + sync_sched(), with rcu_read_lock() + > rcu_call() it should work again without adding an extra lock. > Except that I need spin_lock_irq for other reasons. I could take the same lock in write-side code and not use RCU at all but using RCU allows opening/closing input devices without slowing down interrupt handlers so why not use it? -- Dmitry - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
