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[185.121.47.193]) by smtp.gmail.com with ESMTPSA id t18-20020a2e9d12000000b002e29c50c4dcsm1335473lji.27.2024.05.07.02.35.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 07 May 2024 02:35:49 -0700 (PDT) From: "Uladzislau Rezki (Sony)" To: "Paul E . McKenney" Cc: RCU , Neeraj upadhyay , Boqun Feng , Hillf Danton , Joel Fernandes , LKML , Uladzislau Rezki , Oleksiy Avramchenko , Frederic Weisbecker , Ankur Arora , Thomas Gleixner Subject: [PATCH 18/48] rcu: Make TINY_RCU depend on !PREEMPT_RCU rather than !PREEMPTION Date: Tue, 7 May 2024 11:35:00 +0200 Message-Id: <20240507093530.3043-19-urezki@gmail.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240507093530.3043-1-urezki@gmail.com> References: <20240507093530.3043-1-urezki@gmail.com> Precedence: bulk X-Mailing-List: rcu@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: "Paul E. McKenney" 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