The Linux Kernel Mailing List
 help / color / mirror / Atom feed
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


      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]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20220901131436.986-3-thunder.leizhen@huawei.com \
    --to=thunder.leizhen@huawei.com \
    --cc=frederic@kernel.org \
    --cc=jiangshanlai@gmail.com \
    --cc=joel@joelfernandes.org \
    --cc=josh@joshtriplett.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mathieu.desnoyers@efficios.com \
    --cc=paulmck@kernel.org \
    --cc=quic_neeraju@quicinc.com \
    --cc=rcu@vger.kernel.org \
    --cc=rostedt@goodmis.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox