Changes in Kconfig.preempt

c17ee635fd3a482b2ad2bf5e269755c2eae5f25e - Merge drm/drm-fixes into drm-misc-fixes

Mon, 23 Feb 2026 10:09:45 +0100

Merge drm/drm-fixes into drm-misc-fixes7.0-rc1 was just released, let's merge it to kick the new release cycle.Signed-off-by: Maxime Ripard List of files: /linux/kernel/Kconfig.preempt

36ae1c45b2cede43ab2fc679b450060bbf119f1b - Merge tag 'sched-core-2026-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Tue, 10 Feb 2026 21:50:10 +0100

Merge tag 'sched-core-2026-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipPull scheduler updates from Ingo Molnar: "Scheduler Kconfig space updates: - Further consolidate configurable preemption modes (Peter Zijlstra) Reduce the number of architectures that are allowed to offer PREEMPT_NONE and PREEMPT_VOLUNTARY, reducing the number of preemption models from four to just two: 'full' and 'lazy' on up-to-date architectures (arm64, loongarch, powerpc, riscv, s390, x86). None and voluntary are only available as legacy features on platforms that don't implement lazy preemption yet, or which don't even support preemption. The goal is to eventually remove cond_resched() and voluntary preemption altogether. RSEQ based 'scheduler time slice extension' support (Thomas Gleixner and Peter Zijlstra): This allows a thread to request a time slice extension when it enters a critical section to avoid contention on a resource when the thread is scheduled out inside of the critical section. - Add fields and constants for time slice extension - Provide static branch for time slice extensions - Add statistics for time slice extensions - Add prctl() to enable time slice extensions - Implement sys_rseq_slice_yield() - Implement syscall entry work for time slice extensions - Implement time slice extension enforcement timer - Reset slice extension when scheduled - Implement rseq_grant_slice_extension() - entry: Hook up rseq time slice extension - selftests: Implement time slice extension test - Allow registering RSEQ with slice extension - Move slice_ext_nsec to debugfs - Lower default slice extension - selftests/rseq: Add rseq slice histogram script Scheduler performance/scalability improvements: - Update rq->avg_idle when a task is moved to an idle CPU, which improves the scalability of various workloads (Shubhang Kaushik) - Reorder fields in 'struct rq' for better caching (Blake Jones) - Fair scheduler SMP NOHZ balancing code speedups (Shrikanth Hegde): - Move checking for nohz cpus after time check - Change likelyhood of nohz.nr_cpus - Remove nohz.nr_cpus and use weight of cpumask instead - Avoid false sharing for sched_clock_irqtime (Wangyang Guo) - Cleanups (Yury Norov): - Drop useless cpumask_empty() in find_energy_efficient_cpu() - Simplify task_numa_find_cpu() - Use cpumask_weight_and() in sched_balance_find_dst_group() DL scheduler updates: - Add a deadline server for sched_ext tasks (by Andrea Righi and Joel Fernandes, with fixes by Peter Zijlstra) RT scheduler updates: - Skip currently executing CPU in rto_next_cpu() (Chen Jinghuang) Entry code updates and performance improvements (Jinjie Ruan) This is part of the scheduler tree in this cycle due to inter- dependencies with the RSEQ based time slice extension work: - Remove unused syscall argument from syscall_trace_enter() - Rework syscall_exit_to_user_mode_work() for architecture reuse - Add arch_ptrace_report_syscall_entry/exit() - Inline syscall_exit_work() and syscall_trace_enter() Scheduler core updates (Peter Zijlstra): - Rework sched_class::wakeup_preempt() and rq_modified_*() - Avoid rq->lock bouncing in sched_balance_newidle() - Rename rcu_dereference_check_sched_domain() => rcu_dereference_sched_domain() - : Add the __signed_scalar_typeof() helper Fair scheduler updates/refactoring (Peter Zijlstra and Ingo Molnar): - Fold the sched_avg update - Change rcu_dereference_check_sched_domain() to rcu-sched - Switch to rcu_dereference_all() - Remove superfluous rcu_read_lock() - Limit hrtick work - Join two #ifdef CONFIG_FAIR_GROUP_SCHED blocks - Clean up comments in 'struct cfs_rq' - Separate se->vlag from se->vprot - Rename cfs_rq::avg_load to cfs_rq::sum_weight - Rename cfs_rq::avg_vruntime to ::sum_w_vruntime & helper functions - Introduce and use the vruntime_cmp() and vruntime_op() wrappers for wrapped-signed aritmetics - Sort out 'blocked_load*' namespace noise Scheduler debugging code updates: - Export hidden tracepoints to modules (Gabriele Monaco) - Convert copy_from_user() + kstrtouint() to kstrtouint_from_user() (Fushuai Wang) - Add assertions to QUEUE_CLASS (Peter Zijlstra) - hrtimer: Fix tracing oddity (Thomas Gleixner) Misc fixes and cleanups: - Re-evaluate scheduling when migrating queued tasks out of throttled cgroups (Zicheng Qu) - Remove task_struct->faults_disabled_mapping (Christoph Hellwig) - Fix math notation errors in avg_vruntime comment (Zhan Xusheng) - sched/cpufreq: Use %pe format for PTR_ERR() printing (zenghongling)"* tag 'sched-core-2026-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (64 commits) sched: Re-evaluate scheduling when migrating queued tasks out of throttled cgroups sched/cpufreq: Use %pe format for PTR_ERR() printing sched/rt: Skip currently executing CPU in rto_next_cpu() sched/clock: Avoid false sharing for sched_clock_irqtime selftests/sched_ext: Add test for DL server total_bw consistency selftests/sched_ext: Add test for sched_ext dl_server sched/debug: Fix dl_server (re)start conditions sched/debug: Add support to change sched_ext server params sched_ext: Add a DL server for sched_ext tasks sched/debug: Stop and start server based on if it was active sched/debug: Fix updating of ppos on server write ops sched/deadline: Clear the defer params entry: Inline syscall_exit_work() and syscall_trace_enter() entry: Add arch_ptrace_report_syscall_entry/exit() entry: Rework syscall_exit_to_user_mode_work() for architecture reuse entry: Remove unused syscall argument from syscall_trace_enter() sched: remove task_struct->faults_disabled_mapping sched: Update rq->avg_idle when a task is moved to an idle CPU selftests/rseq: Add rseq slice histogram script hrtimer: Fix trace oddity ... List of files: /linux/kernel/Kconfig.preempt

7dadeaa6e851e7d67733f3e24fc53ee107781d0f - sched: Further restrict the preemption modes

Thu, 18 Dec 2025 15:25:10 +0100

sched: Further restrict the preemption modesThe introduction of PREEMPT_LAZY was for multiple reasons: - PREEMPT_RT suffered from over-scheduling, hurting performance compared to !PREEMPT_RT. - the introduction of (more) features that rely on preemption; like folio_zero_user() which can do large memset() without preemption checks. (Xen already had a horrible hack to deal with long running hypercalls) - the endless and uncontrolled sprinkling of cond_resched() -- mostly cargo cult or in response to poor to replicate workloads.By moving to a model that is fundamentally preemptable these things becomemanagable and avoid needing to introduce more horrible hacks.Since this is a requirement; limit PREEMPT_NONE to architectures that do notsupport preemption at all. Further limit PREEMPT_VOLUNTARY to thosearchitectures that do not yet have PREEMPT_LAZY support (with the eventual goalto make this the empty set and completely remove voluntary preemption andcond_resched() -- notably VOLUNTARY is already limited to !ARCH_NO_PREEMPT.)This leaves up-to-date architectures (arm64, loongarch, powerpc, riscv, s390,x86) with only two preemption models: full and lazy.While Lazy has been the recommended setting for a while, not all distributionshave managed to make the switch yet. Force things along. Keep the patch minimalin case of hard to address regressions that might pop up.Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Valentin Schneider Link: https://patch.msgid.link/20251219101502.GB1132199@noisy.programming.kicks-ass.net List of files: /linux/kernel/Kconfig.preempt

a4a508df2aa34f8650afde54ea804321c618f45f - Merge tag 'v6.18' into next

Sat, 13 Dec 2025 10:18:20 +0100

Merge tag 'v6.18' into nextSync up with the mainline to bring in the latest APIs. List of files: /linux/kernel/Kconfig.preempt

cb9f145f638d7afa633632a9290d6ad06caeb8ee - Merge remote-tracking branch 'drm/drm-next' into msm-next-robclark

Sat, 01 Nov 2025 13:47:30 +0100

Merge remote-tracking branch 'drm/drm-next' into msm-next-robclarkBack-merge drm-next to get caught up.Signed-off-by: Rob Clark List of files: /linux/kernel/Kconfig.preempt

82ee50252dc891e3f3b32d923bb4f656d300b772 - Merge drm/drm-next into drm-xe-next

Tue, 14 Oct 2025 11:31:49 +0200

Merge drm/drm-next into drm-xe-nextBackmerging to bring in 6.18-rc1.Signed-off-by: Thomas Hellström List of files: /linux/kernel/Kconfig.preempt

2acee98fcc61052d63fab4539fcb6ee677555645 - Merge drm/drm-next into drm-intel-next

Tue, 14 Oct 2025 09:37:11 +0200

Merge drm/drm-next into drm-intel-nextSync to v6.18-rc1.Signed-off-by: Jani Nikula List of files: /linux/kernel/Kconfig.preempt

9b966ae42235a88eaea714be09ff3d698535bdfe - Merge drm/drm-next into drm-misc-next

Mon, 13 Oct 2025 09:19:19 +0200

Merge drm/drm-next into drm-misc-nextUpdating drm-misc-next to the state of v6.18-rc1.Signed-off-by: Thomas Zimmermann List of files: /linux/kernel/Kconfig.preempt

2ace52718376fdb56aca863da2eebe70d7e2ddb1 - Merge branch 'objtool/core'

Fri, 21 Nov 2025 11:21:20 +0100

Merge branch 'objtool/core'Bring in the UDB and objtool data annotations to avoid conflicts while further extending the bug exceptions.Signed-off-by: Peter Zijlstra List of files: /linux/kernel/Kconfig.preempt

f39b6c468c52745dbca9a842d91c8373fda208ab - Merge tag 'v6.18-rc6' into for-linus

Tue, 18 Nov 2025 08:16:55 +0100

Merge tag 'v6.18-rc6' into for-linusSync up with the mainline to bring in definition ofINPUT_PROP_HAPTIC_TOUCHPAD. List of files: /linux/kernel/Kconfig.preempt

4f38da1f027ea2c9f01bb71daa7a299c191b6940 - spi: Merge up v6.18-rc1

Mon, 13 Oct 2025 14:32:13 +0200

spi: Merge up v6.18-rc1Ensure my CI has a sensible baseline. List of files: /linux/kernel/Kconfig.preempt

ec2e0fb07d789976c601bec19ecced7a501c3705 - Merge tag 'asoc-fix-v6.18-rc1' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus

Thu, 16 Oct 2025 20:14:24 +0200

Merge tag 'asoc-fix-v6.18-rc1' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linusASoC: Fixes for v6.18A moderately large collection of driver specific fixes, plus a few newquirks and device IDs. The NAU8821 changes are a little large but morein mechanical ways than in ways that are complex. List of files: /linux/kernel/Kconfig.preempt

48a710760e10a4f36e11233a21860796ba204b1e - Merge drm/drm-fixes into drm-misc-fixes

Tue, 14 Oct 2025 10:59:58 +0200

Merge drm/drm-fixes into drm-misc-fixesUpdating drm-misc-fixes to the state of v6.18-rc1.Signed-off-by: Thomas Zimmermann List of files: /linux/kernel/Kconfig.preempt

3b2074c77d25f453247163300d5638adfab4e4fa - Merge tag 'irq-core-2025-09-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Wed, 01 Oct 2025 00:55:25 +0200

Merge tag 'irq-core-2025-09-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipPull irq core updates from Thomas Gleixner: "A set of updates for the interrupt core subsystem: - Introduce irq_chip_[startup|shutdown]_parent() to prepare for addressing a few short comings in the PCI/MSI interrupt subsystem. It allows to utilize the interrupt chip startup/shutdown callbacks for initializing the interrupt chip hierarchy properly on certain RISCV implementations and provides a mechanism to reduce the overhead of masking and unmasking PCI/MSI interrupts during operation when the underlying MSI provider can mask the interrupt. The actual usage comes with the interrupt driver pull request. - Add generic error handling for devm_request_*_irq() This allows to remove the zoo of random error printk's all over the usage sites. - Add a mechanism to warn about long-running interrupt handlers Long running interrupt handlers can introduce latencies and tracking them down is a tedious task. The tracking has to be enabled with a threshold on the kernel command line and utilizes a static branch to remove the overhead when disabled. - Update and extend the selftests which validate the CPU hotplug interrupt migration logic - Allow dropping the per CPU softirq lock on PREEMPT_RT kernels, which causes contention and latencies all over the place. The serialization requirements have been pushed down into the actual affected usage sites already. - The usual small cleanups and improvements"* tag 'irq-core-2025-09-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: softirq: Allow to drop the softirq-BKL lock on PREEMPT_RT softirq: Provide a handshake for canceling tasklets via polling genirq/test: Ensure CPU 1 is online for hotplug test genirq/test: Drop CONFIG_GENERIC_IRQ_MIGRATION assumptions genirq/test: Depend on SPARSE_IRQ genirq/test: Fail early if interrupt request fails genirq/test: Factor out fake-virq setup genirq/test: Select IRQ_DOMAIN genirq/test: Fix depth tests on architectures with NOREQUEST by default. genirq: Add support for warning on long-running interrupt handlers genirq/devres: Add error handling in devm_request_*_irq() genirq: Add irq_chip_(startup/shutdown)_parent() genirq: Remove GENERIC_IRQ_LEGACY List of files: /linux/kernel/Kconfig.preempt

3253cb49cbad4772389d6ef55be75db1f97da910 - softirq: Allow to drop the softirq-BKL lock on PREEMPT_RT

Thu, 04 Sep 2025 16:25:25 +0200

softirq: Allow to drop the softirq-BKL lock on PREEMPT_RTsoftirqs are preemptible on PREEMPT_RT. There is synchronisation betweenindividual sections which disable bottom halves. This in turn means thata forced threaded interrupt cannot preempt another forced threadedinterrupt. Instead it will PI-boost the other handler and wait for itscompletion.This is required because code within a softirq section is assumed to benon-preemptible and may expect exclusive access to per-CPU resourcessuch as variables or pinned timers.Code with such expectation has been identified and updated to uselocal_lock_nested_bh() for locking of the per-CPU resource. This means thesoftirq lock can be removed.Disable the softirq synchronization, but add a new config switchCONFIG_PREEMPT_RT_NEEDS_BH_LOCK which allows to re-enable the synchronizedbehavior in case that there are issues, which haven't been detected yet.The softirq_ctrl.cnt accounting remains to let the NOHZ code know ifsoftirqs are currently handled.Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Thomas Gleixner List of files: /linux/kernel/Kconfig.preempt

c771600c6af14749609b49565ffb4cac2959710d - Merge drm/drm-next into drm-intel-gt-next

Wed, 05 Feb 2025 10:29:14 +0100

Merge drm/drm-next into drm-intel-gt-nextWe need4ba4f1afb6a9 ("perf: Generic hotplug support for a PMU with a scope")in order to land a i915 PMU simplification and a fix. That landed in 6.12and we are stuck at 6.9 so lets bump things forward.Signed-off-by: Tvrtko Ursulin List of files: /linux/kernel/Kconfig.preempt

60675d4ca1ef0857e44eba5849b74a3a998d0c0f - Merge branch 'linus' into x86/mm, to pick up fixes

Fri, 20 Dec 2024 10:25:44 +0100

Merge branch 'linus' into x86/mm, to pick up fixesSigned-off-by: Ingo Molnar List of files: /linux/kernel/Kconfig.preempt

25768de50b1f2dbb6ea44bd5148a87fe2c9c3688 - Merge branch 'next' into for-linus

Tue, 21 Jan 2025 06:37:39 +0100

Merge branch 'next' into for-linusPrepare input updates for 6.14 merge window. List of files: /linux/kernel/Kconfig.preempt

6d4a0f4ea72319c9a37c1a7191695467006dd272 - Merge tag 'v6.13-rc3' into next

Tue, 17 Dec 2024 18:40:45 +0100

Merge tag 'v6.13-rc3' into nextSync up with the mainline. List of files: /linux/kernel/Kconfig.preempt

c5fb51b71788926feef0d07f30c8af1d5e4af1a6 - Merge remote-tracking branch 'pm/opp/linux-next' into HEAD

Fri, 03 Jan 2025 16:13:45 +0100

Merge remote-tracking branch 'pm/opp/linux-next' into HEADMerge pm/opp tree to get dev_pm_opp_get_bw()Signed-off-by: Rob Clark List of files: /linux/kernel/Kconfig.preempt