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Wed, 25 Feb 2026 06:54:17 +0100 (CET) Subject: [Linux PPC] Disable PREEMPT To: Shrikanth Hegde , linuxppc-dev , "kvm-ppc@vger.kernel.org" , Madhavan Srinivasan Cc: "R.T.Dickinson" , hypexed@yahoo.com.au, mad skateman , Christian Zigotzky References: <185d7a42-f7b4-44e1-a129-f5989d211c74@linux.ibm.com> <40154f6a-39da-959d-e039-5ab9ff62db3c@xenosoft.de> <709b864f-9daa-4a48-b3d6-39baedce63b2@linux.ibm.com> <843b7c60-23f1-47d0-b4e8-2147c3e40c23@linux.ibm.com> <2a27e6fc-7eb4-41a5-ba88-58f6a22625b5@xenosoft.de> <1d79ec6f-ce7f-4432-80e0-a54fa1668642@linux.ibm.com> From: Christian Zigotzky Organization: A-EON Open Source Message-ID: Date: Wed, 25 Feb 2026 06:54:17 +0100 X-Mailer: BrassMonkey/33.9.1 X-Mailing-List: linuxppc-dev@lists.ozlabs.org List-Id: List-Help: List-Owner: List-Post: List-Archive: , List-Subscribe: , , List-Unsubscribe: Precedence: list MIME-Version: 1.0 In-Reply-To: <1d79ec6f-ce7f-4432-80e0-a54fa1668642@linux.ibm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Hello, We were previously able to disable PREEMPT in the kernel configuration, but the latest kernels now enable it by default and it is no longer possible to disable it. Is it possible to let us decide whether to activate PREEMPT or not? Currently we use the following revert patch for our non-preempt kernels. --- a/kernel/Kconfig.preempt    2026-02-14 10:06:32.000000000 +0000 +++ b/kernel/Kconfig.preempt    2026-02-08 21:03:27.000000000 +0000 @@ -16,13 +16,11 @@ config ARCH_HAS_PREEMPT_LAZY  choice      prompt "Preemption Model" -    default PREEMPT_LAZY if ARCH_HAS_PREEMPT_LAZY      default PREEMPT_NONE  config PREEMPT_NONE      bool "No Forced Preemption (Server)"      depends on !PREEMPT_RT -    depends on ARCH_NO_PREEMPT      select PREEMPT_NONE_BUILD if !PREEMPT_DYNAMIC      help        This is the traditional Linux preemption model, geared towards @@ -37,7 +35,6 @@ config PREEMPT_NONE  config PREEMPT_VOLUNTARY      bool "Voluntary Kernel Preemption (Desktop)" -    depends on !ARCH_HAS_PREEMPT_LAZY      depends on !ARCH_NO_PREEMPT      depends on !PREEMPT_RT      select PREEMPT_VOLUNTARY_BUILD if !PREEMPT_DYNAMIC --- Thanks in advance, Christian