All of lore.kernel.org
 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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.