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>,
Ti Zhou <x2019cwm@stfx.ca>, Yunfeng Ye <yeyunfeng@huawei.com>,
"Paul E . McKenney" <paulmck@kernel.org>,
Marcelo Tosatti <mtosatti@redhat.com>,
Ingo Molnar <mingo@kernel.org>
Subject: [PATCH 07/10] tick/nohz: Update nohz_full Kconfig help
Date: Thu, 11 Mar 2021 13:37:05 +0100 [thread overview]
Message-ID: <20210311123708.23501-8-frederic@kernel.org> (raw)
In-Reply-To: <20210311123708.23501-1-frederic@kernel.org>
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
next prev parent reply other threads:[~2021-03-11 12:38 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-11 12:36 [PATCH 00/10] tick/nohz updates Frederic Weisbecker
2021-03-11 12:36 ` [PATCH 01/10] tick/nohz: Prevent tick_nohz_get_sleep_length() from returning negative value Frederic Weisbecker
2021-03-16 12:21 ` Peter Zijlstra
2021-03-16 13:37 ` Frederic Weisbecker
2021-03-16 14:35 ` Peter Zijlstra
2021-03-16 14:53 ` Frederic Weisbecker
2021-03-16 15:26 ` Rafael J. Wysocki
2021-03-16 15:57 ` 回复: " Zhou Ti (x2019cwm)
2021-03-16 16:08 ` Zhou Ti (x2019cwm)
2021-03-16 16:25 ` Peter Zijlstra
2021-03-17 21:49 ` Zhou Ti (x2019cwm)
2021-03-25 13:14 ` Frederic Weisbecker
2021-03-25 18:56 ` Rafael J. Wysocki
2021-03-25 19:18 ` Zhou Ti (x2019cwm)
2021-03-25 19:50 ` Rafael J. Wysocki
2021-03-25 20:37 ` Zhou Ti (x2019cwm)
2021-03-26 17:01 ` Rafael J. Wysocki
2021-03-26 17:53 ` Zhou Ti (x2019cwm)
2021-03-26 18:54 ` Rafael J. Wysocki
2021-03-26 22:53 ` Zhou Ti (x2019cwm)
2021-03-29 12:44 ` Rafael J. Wysocki
2021-03-29 14:49 ` Zhou Ti (x2019cwm)
2021-03-11 12:37 ` [PATCH 02/10] tick/nohz: Add tick_nohz_full_this_cpu() Frederic Weisbecker
2021-03-16 12:28 ` Peter Zijlstra
2021-03-16 13:05 ` Frederic Weisbecker
2021-03-11 12:37 ` [PATCH 03/10] tick/nohz: Conditionally restart tick on idle exit Frederic Weisbecker
2021-03-11 12:37 ` [PATCH 04/10] tick/nohz: Remove superflous check for CONFIG_VIRT_CPU_ACCOUNTING_NATIVE Frederic Weisbecker
2021-03-11 12:37 ` [PATCH 05/10] tick/nohz: Update idle_exittime on actual idle exit Frederic Weisbecker
2021-03-11 12:37 ` [PATCH 06/10] timer: Report ignored local enqueue in nohz mode Frederic Weisbecker
2021-03-16 15:27 ` Peter Zijlstra
2021-03-25 13:07 ` Frederic Weisbecker
2021-03-11 12:37 ` Frederic Weisbecker [this message]
2021-03-11 12:37 ` [PATCH 08/10] tick/nohz: Only wakeup a single target cpu when kicking a task Frederic Weisbecker
2021-03-11 12:37 ` [PATCH 09/10] tick/nohz: Change signal tick dependency to wakeup CPUs of member tasks Frederic Weisbecker
2021-03-11 12:37 ` [PATCH 10/10] tick/nohz: Kick only _queued_ task whose tick dependency is updated Frederic Weisbecker
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