From c1ec7c158090ab968ab9022a9f67e7d88d66ee61 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Wed, 14 Feb 2024 15:33:55 -0800 Subject: [PATCH] rcu: Make TINY_RCU depend on !PREEMPT_RCU rather than !PREEMPTION Right now, TINY_RCU depends on (!PREEMPTION && !SMP), which has served the kernel well for many years due to the fact that PREEMPT_RCU is normally a synonym for PREEMPTION. But with the advent of lazy preemption, it will be possible to have non-preemptible RCU in a preemptible kernel, so that kernels could be built with PREEMPT_RCU=n and PREEMPTION=y. This commit therefore makes TINY_RCU depend on (!PREEMPT_RCU && !SMP), thus allowing for a non-preemptible RCU in preemptible kernels. Signed-off-by: Paul E. McKenney Cc: Ankur Arora Cc: Thomas Gleixner Signed-off-by: Uladzislau Rezki (Sony) --- kernel/rcu/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/rcu/Kconfig b/kernel/rcu/Kconfig index e7d2dd267593..7dca0138260c 100644 --- a/kernel/rcu/Kconfig +++ b/kernel/rcu/Kconfig @@ -31,7 +31,7 @@ config PREEMPT_RCU config TINY_RCU bool - default y if !PREEMPTION && !SMP + default y if !PREEMPT_RCU && !SMP help This option selects the RCU implementation that is designed for UP systems from which real-time response