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Wysocki" , Ti Zhou , Yunfeng Ye , "Paul E . McKenney" , Marcelo Tosatti , Ingo Molnar Subject: [PATCH 07/10] tick/nohz: Update nohz_full Kconfig help Date: Thu, 11 Mar 2021 13:37:05 +0100 Message-Id: <20210311123708.23501-8-frederic@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210311123708.23501-1-frederic@kernel.org> References: <20210311123708.23501-1-frederic@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org CONFIG_NO_HZ_FULL behaves just like CONFIG_NO_HZ_IDLE by default. Reassure distros about it. Signed-off-by: Frederic Weisbecker Cc: Yunfeng Ye Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Marcelo Tosatti Cc: Rafael J. Wysocki --- 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