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From:   Frederic Weisbecker <frederic@kernel.org>
To:     Peter Zijlstra <peterz@infradead.org>,
        Thomas Gleixner <tglx@linutronix.de>
Cc:     LKML <linux-kernel@vger.kernel.org>,
        Frederic Weisbecker <frederic@kernel.org>,
        "Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
        Yunfeng Ye <yeyunfeng@huawei.com>,
        Marcelo Tosatti <mtosatti@redhat.com>
Subject: [PATCH 5/8] tick/nohz: Update nohz_full Kconfig help
Date:   Thu, 22 Apr 2021 14:01:55 +0200
Message-Id: <20210422120158.33629-6-frederic@kernel.org>
In-Reply-To: <20210422120158.33629-1-frederic@kernel.org>
References: <20210422120158.33629-1-frederic@kernel.org>
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CONFIG_NO_HZ_FULL behaves just like CONFIG_NO_HZ_IDLE by default.
Reassure distros about it.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Yunfeng Ye <yeyunfeng@huawei.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 kernel/time/Kconfig | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig
index 83e158d016ba..6649e1d2dba5 100644
--- a/kernel/time/Kconfig
+++ b/kernel/time/Kconfig
@@ -117,13 +117,14 @@ config NO_HZ_FULL
 	 the task mostly runs in userspace and has few kernel activity.
 
 	 You need to fill up the nohz_full boot parameter with the
-	 desired range of dynticks CPUs.
+	 desired range of dynticks CPUs to use it. This is implemented at
+	 the expense of some overhead in user <-> kernel transitions:
+	 syscalls, exceptions and interrupts.
 
-	 This is implemented at the expense of some overhead in user <-> kernel
-	 transitions: syscalls, exceptions and interrupts. Even when it's
-	 dynamically off.
+	 By default, without passing nohz_full parameter, this behaves just
+	 like NO_HZ_IDLE.
 
-	 Say N.
+	 If you're a distro say Y.
 
 endchoice
 
-- 
2.25.1