Re: BUG: ib_mad ftrace event unsupported migration

[Steven Rostedt]

On Wed, 2 Nov 2022 11:04:44 -0300
Jason Gunthorpe <jgg@xxxxxxxx> wrote:

> So this tracepoint is just wrong, you can't call a sleepable function
> from a tracepoint like that?
> 
> Presumably lockdep would/should warn about this?

Why didn't it trigger a "scheduling while atomic" bug? That should
happen if you call a sleeping function while preemption is disabled. Or
does this function explicitly enable preemption? Which nothing checks
if you enable preemption while recording to the ring buffer. I guess we
could add that check, but this is not something that commonly happens
enough to bother.

-- Steve