On Mon, Oct 22, 2007 at 09:10:34PM +0200, Arnd Bergmann wrote: > On a related note, should we encourage the use of spin_lock() and > spin_lock_irq() instead of spin_lock_irqsave() where possible?
spin_lock(), certainly. On PowerPC, I'm reliably informed it's fewer instructions to save/restore than it is to disable/enable. So no clear advantage there. > On some architectures, accessing the interrupt flag is a heavyweight > operation, especially when running under a hypervisor, so a number > of drivers could benefit from being converted to not save the flags > at all instead of just changing the type of the flags variable. We certainly don't want to encourage people to blindly make those conversions ... and I've seen the results of encouraging kernel janitors to do things a certain way. -- Intel are signing my paycheques ... these opinions are still mine "Bill, look, we understand that you're interested in selling us this operating system, but compare it to ours. We can't possibly take such a retrograde step." - 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/
