On Mon, May 04, 2020 at 06:56:29PM +0200, Uladzislau Rezki wrote: > > > > > > For single argument we can drop the lock before the entry to the page > > > allocator. Because it follows might_sleep() anotation we avoid of having > > > a situation when spinlock(rt mutex) is taken from any atomic context. > > > > > > Since the lock is dropped the current context can be interrupted by > > > an IRQ which in its turn can also call kvfree_rcu() on current CPU. > > > In that case it must be double argument(single is not allowed) kvfree_rcu() > > > call. For PREEMPT_RT if no cache everything is reverted to rcu_head usage, > > > i.e. the entry to page allocator is bypassed. > > > > > > It can be addressed as a separate patch and send out later on if we > > > are on the same page. > > > > > > Paul, Joel what are your opinions? > > > > I strongly prefer that it be removed from the series. I do understand > > that this is a bit more hassle right now, but this does help avoid > > confusion in the future, plus perhaps also avoiding issues with future > > bisections. > > > We have already decided to get rid of it, i mean small allocations(dynamic > rcu_head attaching). I will exclude it from next patch-set version. Very good, and thank you!!! Thanx, Paul
