linux/kernel
Linus Torvalds e32cde8d2b sched_ext: A second set of fixes for v6.12-rc1
- When sched_ext is in bypass mode (e.g. while disabling the BPF scheduler),
   it was using one DSQ to implement global FIFO scheduling as all it has to
   do is guaranteeing reasonable forward progress. On multi-socket machines,
   this can lead to live-lock conditions under certain workloads. Fixed by
   splitting the queue used for FIFO scheduling per NUMA node. This required
   several preparation patches.
 
 - Hotplug tests on powerpc could reliably trigger deadlock while enabling a
   BPF scheduler. This was caused by cpu_hotplug_lock nesting inside
   scx_fork_rwsem and then CPU hotplug path trying to fork a new thread while
   holding cpu_hotplug_lock. Fixed by restructuring locking in enable and
   disable paths so that the two locks are not coupled. This required several
   preparation patches which also fixed a couple other issues in the enable
   path.
 
 - A build fix for !CONFIG_SMP.
 
 - Userspace tooling sync and updates.
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Merge tag 'sched_ext-for-6.12-rc1-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext

Pull sched_ext fixes from Tejun Heo:

 - When sched_ext is in bypass mode (e.g. while disabling the BPF
   scheduler), it was using one DSQ to implement global FIFO scheduling
   as all it has to do is guaranteeing reasonable forward progress.

   On multi-socket machines, this can lead to live-lock conditions under
   certain workloads. Fixed by splitting the queue used for FIFO
   scheduling per NUMA node. This required several preparation patches.

 - Hotplug tests on powerpc could reliably trigger deadlock while
   enabling a BPF scheduler.

   This was caused by cpu_hotplug_lock nesting inside scx_fork_rwsem and
   then CPU hotplug path trying to fork a new thread while holding
   cpu_hotplug_lock.

   Fixed by restructuring locking in enable and disable paths so that
   the two locks are not coupled. This required several preparation
   patches which also fixed a couple other issues in the enable path.

 - A build fix for !CONFIG_SMP

 - Userspace tooling sync and updates

* tag 'sched_ext-for-6.12-rc1-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext:
  sched_ext: Remove redundant p->nr_cpus_allowed checker
  sched_ext: Decouple locks in scx_ops_enable()
  sched_ext: Decouple locks in scx_ops_disable_workfn()
  sched_ext: Add scx_cgroup_enabled to gate cgroup operations and fix scx_tg_online()
  sched_ext: Enable scx_ops_init_task() separately
  sched_ext: Fix SCX_TASK_INIT -> SCX_TASK_READY transitions in scx_ops_enable()
  sched_ext: Initialize in bypass mode
  sched_ext: Remove SCX_OPS_PREPPING
  sched_ext: Relocate check_hotplug_seq() call in scx_ops_enable()
  sched_ext: Use shorter slice while bypassing
  sched_ext: Split the global DSQ per NUMA node
  sched_ext: Relocate find_user_dsq()
  sched_ext: Allow only user DSQs for scx_bpf_consume(), scx_bpf_dsq_nr_queued() and bpf_iter_scx_dsq_new()
  scx_flatcg: Use a user DSQ for fallback instead of SCX_DSQ_GLOBAL
  tools/sched_ext: Receive misc updates from SCX repo
  sched_ext: Add __COMPAT helpers for features added during v6.12 devel cycle
  sched_ext: Build fix for !CONFIG_SMP
2024-09-30 12:58:17 -07:00
..
bpf [tree-wide] finally take no_llseek out 2024-09-27 08:18:43 -07:00
cgroup struct fd layout change (and conversion to accessor helpers) 2024-09-23 09:35:36 -07:00
configs tinyconfig: remove unnecessary 'is not set' for choice blocks 2024-09-01 20:34:38 +09:00
debug kdb: Get rid of redundant kdb_curr_task() 2024-06-21 15:49:29 +01:00
dma dma-mapping: report unlimited DMA addressing in IOMMU DMA path 2024-09-23 08:38:56 +02:00
entry treewide: context_tracking: Rename CONTEXT_* into CT_STATE_* 2024-07-29 07:33:10 +05:30
events uprobes: fix kernel info leak via "[uprobes]" vma 2024-09-30 08:19:11 +09:00
futex fault-inject: improve build for CONFIG_FAULT_INJECTION=n 2024-09-01 20:43:33 -07:00
gcov gcov: add support for GCC 14 2024-06-15 10:43:06 -07:00
irq pci-v6.12-changes 2024-09-23 12:47:06 -07:00
kcsan kcsan: Use min() to fix Coccinelle warning 2024-08-01 16:40:44 -07:00
livepatch livepatch: Replace snprintf() with sysfs_emit() 2024-07-02 16:56:18 +02:00
locking Locking changes for v6.12: 2024-09-29 08:51:30 -07:00
module Modules changes for v6.12-rc1 2024-09-28 09:06:15 -07:00
power [tree-wide] finally take no_llseek out 2024-09-27 08:18:43 -07:00
printk drm next for 6.12-rc1 2024-09-19 10:18:15 +02:00
rcu slab updates for 6.12 2024-09-18 08:53:53 +02:00
sched sched_ext: Remove redundant p->nr_cpus_allowed checker 2024-09-27 10:23:45 -10:00
time [tree-wide] finally take no_llseek out 2024-09-27 08:18:43 -07:00
trace [tree-wide] finally take no_llseek out 2024-09-27 08:18:43 -07:00
.gitignore
acct.c kernel misc: Remove the now superfluous sentinel elements from ctl_table array 2024-04-24 09:43:53 +02:00
async.c async: Use a dedicated unbound workqueue with raised min_active 2024-02-09 11:13:59 -10:00
audit_fsnotify.c
audit_tree.c fsnotify: create a wrapper fsnotify_find_inode_mark() 2024-04-04 16:24:16 +02:00
audit_watch.c fsnotify: create a wrapper fsnotify_find_inode_mark() 2024-04-04 16:24:16 +02:00
audit.c audit: Make use of str_enabled_disabled() helper 2024-09-03 16:35:16 -04:00
audit.h
auditfilter.c audit: use task_tgid_nr() instead of task_pid_nr() 2024-08-28 16:48:28 -04:00
auditsc.c audit: use task_tgid_nr() instead of task_pid_nr() 2024-08-28 16:48:28 -04:00
backtracetest.c backtracetest: add MODULE_DESCRIPTION() 2024-06-24 22:24:55 -07:00
bounds.c bounds: Use the right number of bits for power-of-two CONFIG_NR_CPUS 2024-04-29 08:29:29 -07:00
capability.c
cfi.c
compat.c
configs.c
context_tracking.c context_tracking, rcu: Rename rcu_dyntick trace event into rcu_watching 2024-08-15 21:30:43 +05:30
cpu_pm.c
cpu.c Updates for timers and timekeeping: 2024-09-17 07:25:37 +02:00
crash_core.c Document/kexec: generalize crash hotplug description 2024-09-01 20:43:37 -07:00
crash_reserve.c crash: fix crash memory reserve exceed system memory bug 2024-09-01 20:43:30 -07:00
cred.c cred: Use KMEM_CACHE() instead of kmem_cache_create() 2024-02-23 17:33:31 -05:00
delayacct.c sysctl: treewide: constify the ctl_table argument of proc_handlers 2024-07-24 20:59:29 +02:00
dma.c
elfcorehdr.c crash: remove dependency of FA_DUMP on CRASH_DUMP 2024-02-23 17:48:22 -08:00
exec_domain.c
exit.c ALong with the usual shower of singleton patches, notable patch series in 2024-09-21 07:29:05 -07:00
exit.h
extable.c
fail_function.c
fork.c memblock: updates for 6.12-rc1 2024-09-25 11:35:19 -07:00
freezer.c sched,freezer: Mark TASK_FROZEN special 2024-08-17 11:06:44 +02:00
gen_kheaders.sh kheaders: use command -v to test for existence of cpio 2024-05-30 01:13:20 +09:00
groups.c
hung_task.c sysctl: treewide: constify the ctl_table argument of proc_handlers 2024-07-24 20:59:29 +02:00
iomem.c
irq_work.c
jump_label.c jump_label: Fix static_key_slow_dec() yet again 2024-09-10 11:57:27 +02:00
kallsyms_internal.h kallsyms: get rid of code for absolute kallsyms 2024-07-20 16:33:21 +09:00
kallsyms_selftest.c kallsyms: Match symbols exactly with CONFIG_LTO_CLANG 2024-08-15 09:33:35 -07:00
kallsyms_selftest.h
kallsyms.c kallsyms: Match symbols exactly with CONFIG_LTO_CLANG 2024-08-15 09:33:35 -07:00
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.kexec crash: clean up kdump related config items 2024-02-23 17:48:22 -08:00
Kconfig.locks
Kconfig.preempt sched_ext: Build fix on !CONFIG_STACKTRACE[_SUPPORT] 2024-08-01 07:08:01 -10:00
kcov.c Updates for KCOV instrumentation on x86: 2024-09-17 12:40:34 +02:00
kexec_core.c sysctl: treewide: constify the ctl_table argument of proc_handlers 2024-07-24 20:59:29 +02:00
kexec_elf.c
kexec_file.c kexec_file: fix elfcorehdr digest exclusion when CONFIG_CRASH_HOTPLUG=y 2024-09-01 17:59:01 -07:00
kexec_internal.h kexec: use atomic_try_cmpxchg_acquire() in kexec_trylock() 2024-09-01 20:43:23 -07:00
kexec.c crash: add a new kexec flag for hotplug support 2024-04-23 14:59:01 +10:00
kheaders.c
kprobes.c kprobes: Fix to check symbol prefixes correctly 2024-08-05 14:04:03 +09:00
ksyms_common.c
ksysfs.c profiling: remove prof_cpu_mask 2024-07-29 10:45:54 -07:00
kthread.c kthread: Fix task state in kthread worker if being frozen 2024-09-10 09:51:14 +02:00
latencytop.c sysctl: treewide: constify the ctl_table argument of proc_handlers 2024-07-24 20:59:29 +02:00
Makefile mm: move kernel/numa.c to mm/ 2024-09-03 21:15:26 -07:00
module_signature.c
notifier.c
nsproxy.c introduce fd_file(), convert all accessors to it. 2024-08-12 22:00:43 -04:00
padata.c This update includes the following changes: 2024-09-16 06:28:28 +02:00
panic.c drm next for 6.12-rc1 2024-09-19 10:18:15 +02:00
params.c params: Fix multi-line comment style 2023-12-01 09:51:44 -08:00
pid_namespace.c sysctl: treewide: constify the ctl_table argument of proc_handlers 2024-07-24 20:59:29 +02:00
pid_sysctl.h sysctl: treewide: constify the ctl_table argument of proc_handlers 2024-07-24 20:59:29 +02:00
pid.c introduce fd_file(), convert all accessors to it. 2024-08-12 22:00:43 -04:00
profile.c profiling: remove profile=sleep support 2024-08-04 13:36:28 -07:00
ptrace.c ptrace_attach: shift send(SIGSTOP) into ptrace_set_stopped() 2024-02-22 15:38:52 -08:00
range.c
reboot.c kernel misc: Remove the now superfluous sentinel elements from ctl_table array 2024-04-24 09:43:53 +02:00
regset.c regset: use kvzalloc() for regset_get_alloc() 2024-04-25 21:07:03 -07:00
relay.c [tree-wide] finally take no_llseek out 2024-09-27 08:18:43 -07:00
resource_kunit.c resource, kunit: add test case for region_intersects() 2024-09-17 01:07:00 -07:00
resource.c ALong with the usual shower of singleton patches, notable patch series in 2024-09-21 07:29:05 -07:00
rseq.c
scftorture.c scftorture: Make torture_type static 2024-05-30 15:31:51 -07:00
scs.c
seccomp.c sysctl: treewide: constify the ctl_table argument of proc_handlers 2024-07-24 20:59:29 +02:00
signal.c Revert "binfmt_elf, coredump: Log the reason of the failed core dumps" 2024-09-26 11:39:02 -07:00
smp.c smp: print only local CPU info when sched_clock goes backward 2024-08-15 00:06:48 +05:30
smpboot.c
smpboot.h
softirq.c softirq: Remove unused 'action' parameter from action callback 2024-08-20 17:13:40 +02:00
stackleak.c sysctl: treewide: constify the ctl_table argument of proc_handlers 2024-07-24 20:59:29 +02:00
stacktrace.c stacktrace: fix kernel-doc typo 2023-12-29 12:22:29 -08:00
static_call_inline.c static_call: Replace pointless WARN_ON() in static_call_module_notify() 2024-09-06 16:29:22 +02:00
static_call.c
stop_machine.c rcu: Rename rcu_momentary_dyntick_idle() into rcu_momentary_eqs() 2024-08-15 21:30:42 +05:30
sys_ni.c Probes updates for v6.11: 2024-07-18 12:19:20 -07:00
sys.c struct fd layout change (and conversion to accessor helpers) 2024-09-23 09:35:36 -07:00
sysctl-test.c sysctl: Add module description to sysctl-testing 2024-06-03 15:20:37 +02:00
sysctl.c sysctl: treewide: constify the ctl_table argument of proc_handlers 2024-07-24 20:59:29 +02:00
task_work.c task_work: make TWA_NMI_CURRENT handling conditional on IRQ_WORK 2024-07-29 12:05:06 -07:00
taskstats.c introduce fd_file(), convert all accessors to it. 2024-08-12 22:00:43 -04:00
torture.c torture: Add MODULE_DESCRIPTION() 2024-05-30 15:31:38 -07:00
tracepoint.c tracepoint: Support iterating tracepoints in a loading module 2024-09-25 23:23:44 +09:00
tsacct.c tsacct: replace strncpy() with strscpy() 2024-07-12 16:39:53 -07:00
ucount.c sysctl changes for v6.10-rc1 2024-05-17 17:31:24 -07:00
uid16.c
uid16.h
umh.c sysctl: treewide: constify the ctl_table argument of proc_handlers 2024-07-24 20:59:29 +02:00
up.c
user_namespace.c user_namespace: use kmemdup_array() instead of kmemdup() for multiple allocation 2024-09-09 16:47:42 -07:00
user-return-notifier.c
user.c uidgid: make sure we fit into one cacheline 2024-09-12 12:16:09 +02:00
usermode_driver.c
utsname_sysctl.c sysctl: treewide: constify the ctl_table argument of proc_handlers 2024-07-24 20:59:29 +02:00
utsname.c
vhost_task.c vhost_task: Handle SIGKILL by flushing work and exiting 2024-05-22 08:31:15 -04:00
vmcore_info.c mm: support only one page_type per page 2024-09-03 21:15:43 -07:00
watch_queue.c introduce fd_file(), convert all accessors to it. 2024-08-12 22:00:43 -04:00
watchdog_buddy.c
watchdog_perf.c watchdog/perf: properly initialize the turbo mode timestamp and rearm counter 2024-07-17 21:11:34 -07:00
watchdog.c watchdog: handle the ENODEV failure case of lockup_detector_delay_init() separately 2024-09-01 20:43:32 -07:00
workqueue_internal.h
workqueue.c workqueue: Changes for v6.12 2024-09-18 06:59:44 +02:00