On Thu, May 24, 2018 at 03:38:51PM +0800, Jason Yan wrote: > > > On 2018/5/24 15:15, Sebastian Andrzej Siewior wrote: > > On 2018-05-24 10:58:44 [+0800], Jason Yan wrote: > > > I think it's fine to delete this irq save code. As for the "TODO" > > > comment, I think we can add: > > > > > > BUG_ON(!irqs_disabled()); > > > > > > or > > > > > > WARN_ON_ONCE(!irqs_disabled()); > > > > no, please don't do this. Please add instead > > lockdep_assert_held() > > > > on the lock in question and let lockdep to its work. Lockdep has way > > better coverage than your irqs_disabled() check which also breaks RT. > > > > lockdep_assert_held() cannot detect the irq state, it can only detect > whether we have held the lock. I think Sebastian wanted to say lockdep_assert_irqs_disabled(). Either way, please never ever use BUG_ON() (even WARN_ON() is questionable as some people actually use panic_on_oops). It causes nasty bugs at customer sites. Byte, Johannes -- Johannes Thumshirn Storage jthumshirn@xxxxxxx +49 911 74053 689 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: Felix Imendörffer, Jane Smithard, Graham Norton HRB 21284 (AG Nürnberg) Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850
