On Wed, 21 Mar 2018, Linus Torvalds wrote: > [ Adding PeterZ to participants due to query about lockdep_assert() ] > > On Wed, Mar 21, 2018 at 8:38 AM, Arnaldo Carvalho de Melo > <acme@xxxxxxxxxx> wrote: > > > > assert_spin_locked(&cmd->t_state_lock); > > - WARN_ON_ONCE(!irqs_disabled()); > > + WARN_ON_ONCE_NONRT(!irqs_disabled()); > > Ugh. > > Can't we just replace both of those with a lockdep annotation? > > Does "lockdep_assert_held()" already verify the irq contextr, or do we > need lockdep_assert_irqs_disabled() too? > > Honestly, the old-fashioned way of doing verification of state by hand > is understandable, but it's legacy and kind of pointless when we have > much better tools these days. > > I'm perfectly willing to leave old assertions in place, but if they > need fixing anyway, I'd damn well want to fix them *right* instead of > starting to just add more piles of hacks on top of the old model. > > Because when the details of the locking rules depend on RT vs non-RT, > I want the checks to make sense. And presumably lockdep is the thing > that really knows what the status of a lock is, no? We are working on replacing the _NONRT _RT variants with proper lockdep mechnisms which are aware of the RT vs. non-RT magic under the hood. Just not there yet. Thanks, tglx
