> stackdepot is severely limited in what kernel facilities it may use > due to being used by such low level facilities as the allocator > itself. RCU can be done quite low level too (e.g. there is NMI safe RCU) > > I've been suggesting percpu-rwsem here, but looking at it in more > detail that doesn't work because percpu-rwsem wants to sleep, but > stackdepot must work in non-sleepable contexts. :-/ Yes something per CPU would work too I suppose. We used to have big reader spinlocks for this. -Andi
