On 2024-10-31 08:35:45 [+0100], Vlastimil Babka wrote: > On 10/31/24 08:21, Sebastian Andrzej Siewior wrote: > > On 2024-10-30 16:10:58 [-0700], Paul E. McKenney wrote: > >> > >> So I need to avoid calling kfree() within an smp_call_function() handler? > > > > Yes. No kmalloc()/ kfree() in IRQ context. > > However, isn't this the case that the rule is actually about hardirq context > on RT, and most of these operations that are in IRQ context on !RT become > the threaded interrupt context on RT, so they are actually fine? Or is smp > call callback a hardirq context on RT and thus it really can't do those > operations? interrupt handlers as of request_irq() are forced-threaded on RT so you can do kmalloc()/ kfree() there. smp_call_function.*() on the other hand are not threaded and invoked directly within the IRQ context. > Vlastimil > Sebastian
