> On Wed, 2 Nov 2022 11:24:20 -0300 > Jason Gunthorpe <jgg@xxxxxxxx> wrote: > > > No, it doesn't muck with preemption, it will have some sleeping lock, > > eg mlx5_ib_query_pkey() does a memory allocation as the first thing > > > > It seems like a bug that calling kmalloc(GFP_KERNEL)/might_sleep() > > from within a tracepoint doesn't trigger a warning? > > Has nothing to do with tracepoints. You could call it a bug that it > doesn't trigger a warning when preemption is disabled. But then again, > it would if you enabled DEBUG_PREEMPT and possibly LOCKDEP too. So, I chalk > this up to a lack of proper testing. > disagree, without CONFIG_PREEMPTION (which is the default case in some destros) we will not get any warning, because there will not be preamption disable. second issue I see and maybe it is only me, is that the assuption of atomicity in trace is not a common knowledge for trace users.
