Joel Fernandes <joel@xxxxxxxxxxxxxxxxx> writes: > Hi, Thomas, > Thanks for your reply! I replied below. > > On 3/11/2024 3:12 PM, Thomas Gleixner wrote: >> On Mon, Mar 11 2024 at 11:25, Joel Fernandes wrote: [ ... ] >> What's wrong with the combination of PREEMPT_AUTO=y and PREEMPT_RCU=n? >> Paul and me agreed long ago that this needs to be supported. > > There's nothing wrong with it. Its just a bit quirky (again just a point of > view), that for a configuration that causes preemption (similar to > CONFIG_PREEMPT=y), that PREEMPT_RCU can be disabled. After all, again with > CONFIG_PREEMPT=y, PREEMPT_RCU cannot be currently disabled. I think the argument was that PREEMPT_RCU=y is suboptimal for certain workloads, and those configurations might prefer the stronger forward-progress guarantees that PREEMPT_RCU=n provides. See this: https://lore.kernel.org/lkml/73ecce1c-d321-4579-b892-13b1e0a0620a@paulmck-laptop/T/#m6aab5a6fd5f1fd4c3dc9282ce564e64f2fa6cdc3 and the surrounding thread. Thanks -- ankur
