From: Zhen Lei <thunder.leizhen@huawei.com>
To: "Paul E . McKenney" <paulmck@kernel.org>,
Frederic Weisbecker <frederic@kernel.org>,
Neeraj Upadhyay <quic_neeraju@quicinc.com>,
"Josh Triplett" <josh@joshtriplett.org>,
Steven Rostedt <rostedt@goodmis.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Lai Jiangshan <jiangshanlai@gmail.com>,
Joel Fernandes <joel@joelfernandes.org>, <rcu@vger.kernel.org>,
<linux-kernel@vger.kernel.org>
Cc: Zhen Lei <thunder.leizhen@huawei.com>
Subject: [PATCH v6 2/2] rcu: Offload callback processing from all CPUs in the absence of rcu_nocbs=
Date: Thu, 1 Sep 2022 21:14:36 +0800 [thread overview]
Message-ID: <20220901131436.986-3-thunder.leizhen@huawei.com> (raw)
In-Reply-To: <20220901131436.986-1-thunder.leizhen@huawei.com>
Offload callback processing from all CPUs as long as there is no
"rcu_nocbs=" boot parameter. This also means: whether
CONFIG_RCU_NOCB_CPU_DEFAULT_ALL=y takes effect does not depend on
the absence of "nohz_full=".
Suggested-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
---
kernel/rcu/Kconfig | 4 ++--
kernel/rcu/tree_nocb.h | 2 +-
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/kernel/rcu/Kconfig b/kernel/rcu/Kconfig
index d471d22a5e21b43..35b94f5f6767f00 100644
--- a/kernel/rcu/Kconfig
+++ b/kernel/rcu/Kconfig
@@ -270,8 +270,8 @@ config RCU_NOCB_CPU_DEFAULT_ALL
default n
help
Use this option to offload callback processing from all CPUs
- by default, in the absence of the rcu_nocbs or nohz_full boot
- parameter. This also avoids the need to use any boot parameters
+ by default, in the absence of the rcu_nocbs boot parameter.
+ This also avoids the need to use any boot parameters
to achieve the effect of offloading all CPUs on boot.
Say Y here if you want offload all CPUs by default on boot.
diff --git a/kernel/rcu/tree_nocb.h b/kernel/rcu/tree_nocb.h
index 8b6dceeabde0b4d..cfbdd78d6c33158 100644
--- a/kernel/rcu/tree_nocb.h
+++ b/kernel/rcu/tree_nocb.h
@@ -1219,7 +1219,7 @@ void __init rcu_init_nohz(void)
#endif
#if defined(CONFIG_RCU_NOCB_CPU_DEFAULT_ALL)
- if (!rcu_state.nocb_is_setup && !cpumask)
+ if (!rcu_state.nocb_is_setup)
cpumask = cpu_possible_mask;
#endif
--
2.25.1
prev parent reply other threads:[~2022-09-01 13:19 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-01 13:14 [PATCH v6 0/2] rcu/nocb: Delete local variable 'need_rcu_nocb_mask' in rcu_init_nohz() Zhen Lei
2022-09-01 13:14 ` [PATCH v6 1/2] rcu: Simplify rcu_init_nohz() cpumask handling Zhen Lei
2022-09-01 13:25 ` Leizhen (ThunderTown)
2022-09-01 16:54 ` Paul E. McKenney
2022-09-07 11:04 ` Frederic Weisbecker
2022-09-13 1:46 ` Leizhen (ThunderTown)
2022-09-01 13:14 ` Zhen Lei [this message]
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