From: Christian Zigotzky <chzigotzky@xenosoft.de>
To: Shrikanth Hegde <sshegde@linux.ibm.com>,
linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
"kvm-ppc@vger.kernel.org" <kvm-ppc@vger.kernel.org>,
Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: "R.T.Dickinson" <rtd2@xtra.co.nz>,
hypexed@yahoo.com.au, mad skateman <madskateman@gmail.com>,
Christian Zigotzky <info@xenosoft.de>
Subject: [Linux PPC] Disable PREEMPT
Date: Wed, 25 Feb 2026 06:54:17 +0100 [thread overview]
Message-ID: <e425cd24-e19a-3860-aad2-11e91af8323f@xenosoft.de> (raw)
In-Reply-To: <1d79ec6f-ce7f-4432-80e0-a54fa1668642@linux.ibm.com>
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
next prev parent reply other threads:[~2026-02-25 5:54 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-14 14:02 [Linux PPC] KVM PR and KVM HV do not work if the kernel was compiled with PREEMPT Christian Zigotzky
2026-02-17 5:02 ` Shrikanth Hegde
2026-02-17 8:52 ` Christian Zigotzky
2026-02-17 9:03 ` Shrikanth Hegde
2026-02-17 9:44 ` Christian Zigotzky
2026-02-17 10:17 ` Madhavan Srinivasan
2026-02-17 10:26 ` Christian Zigotzky
2026-02-17 11:34 ` Shrikanth Hegde
2026-02-21 5:30 ` Christian Zigotzky
2026-02-23 3:45 ` Shrikanth Hegde
2026-02-23 16:48 ` [Linux PPC] 7.0-rc1: e500_mmu.c:923:26: error: assignment to 'struct tlbe_priv *' from incompatible pointer type 'struct tlbe_ref *' Christian Zigotzky
2026-02-23 18:07 ` Christophe Leroy (CS GROUP)
2026-02-23 19:38 ` Christophe Leroy (CS GROUP)
2026-02-23 22:40 ` Kees Cook
2026-02-24 6:30 ` Christian Zigotzky
2026-02-24 7:18 ` Christophe Leroy (CS GROUP)
2026-02-25 5:54 ` Christian Zigotzky [this message]
2026-02-25 6:23 ` [Linux PPC] Disable PREEMPT Shrikanth Hegde
2026-02-25 7:16 ` Christophe Leroy (CS GROUP)
2026-02-25 11:36 ` Peter Zijlstra
2026-02-26 5:37 ` Christian Zigotzky
2026-02-26 13:24 ` Christophe Leroy (CS GROUP)
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