On Thu, Oct 19, 2023 at 12:53:05AM +0200, Thomas Gleixner wrote: > On Wed, Oct 18 2023 at 10:51, Paul E. McKenney wrote: > > On Wed, Oct 18, 2023 at 05:09:46AM -0700, Ankur Arora wrote: > > Can you folks please trim your replies. It's annoying to scroll > through hundreds of quoted lines to figure out that nothing is there. > > >> This probably allows for more configuration flexibility across archs? > >> Would allow for TREE_RCU=y, for instance. That said, so far I've only > >> been working with PREEMPT_RCU=y.) > > > > Then this is a bug that needs to be fixed. We need a way to make > > RCU readers non-preemptible. > > Why? So that we don't get tail latencies from preempted RCU readers that result in memory-usage spikes on systems that have good and sufficient quantities of memory, but which do not have enough memory to tolerate readers being preempted. Thanx, Paul
