[Linux PPC] Disable PREEMPT
Christian Zigotzky <[email protected]> Thu, 26 Feb 2026 06:37:35 +0100
| Newsgroups | org.kernel.vger.kvm-ppc,org.ozlabs.lists.linuxppc-dev |
|---|---|
| Organization | A-EON Open Source |
| Message-ID | <[email protected]> |
On 25/02/26 08:16, Christophe Leroy (CS GROUP) wrote: > +Peter > > Hi Christian, > > Le 25/02/2026 à 06:54, Christian Zigotzky a écrit : >> 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? > > Can you give more details on why you want to be able to deactivate > PREEMPT ? > > Read https://github.com/torvalds/linux/commit/7dadeaa6e851e I use PREEMPT_NONE kernels on my Linux PPC servers. (Without desktop) > > >> >> 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 >> > -- Sent with BrassMonkey 33.9.1 (https://github.com/chzigotzky/Web-Browsers-and-Suites-for-Linux-PPC/releases/tag/BrassMonkey_33.9.1)