"Paul E. McKenney" <paulmck@xxxxxxxxxx> writes: > On Tue, Aug 11, 2020 at 04:44:21PM +0200, Thomas Gleixner wrote: >> Now RCU creates a new thing which enforces to make page allocation in >> atomic context possible on RT. What for? >> >> What's the actual use case in truly atomic context for this new thing on >> an RT kernel? > > It is not just RT kernels. CONFIG_PROVE_RAW_LOCK_NESTING=y propagates > this constraint to all configurations, and a patch in your new favorite > subsystem really did trigger this lockdep check in a non-RT kernel. > >> The actual RCU code disabling interrupts is an implementation detail >> which can easily be mitigated with a local lock. > > In this case, we are in raw-spinlock context on entry to kfree_rcu(). Where?
