kernel_samsung_a53x/kernel
K Prateek Nayak d4d43810f2 sched/fair: Check idle_cpu() before need_resched() to detect ilb CPU turning busy
[ Upstream commit ff47a0acfcce309cf9e175149c75614491953c8f ]

Commit b2a02fc43a1f ("smp: Optimize send_call_function_single_ipi()")
optimizes IPIs to idle CPUs in TIF_POLLING_NRFLAG mode by setting the
TIF_NEED_RESCHED flag in idle task's thread info and relying on
flush_smp_call_function_queue() in idle exit path to run the
call-function. A softirq raised by the call-function is handled shortly
after in do_softirq_post_smp_call_flush() but the TIF_NEED_RESCHED flag
remains set and is only cleared later when schedule_idle() calls
__schedule().

need_resched() check in _nohz_idle_balance() exists to bail out of load
balancing if another task has woken up on the CPU currently in-charge of
idle load balancing which is being processed in SCHED_SOFTIRQ context.
Since the optimization mentioned above overloads the interpretation of
TIF_NEED_RESCHED, check for idle_cpu() before going with the existing
need_resched() check which can catch a genuine task wakeup on an idle
CPU processing SCHED_SOFTIRQ from do_softirq_post_smp_call_flush(), as
well as the case where ksoftirqd needs to be preempted as a result of
new task wakeup or slice expiry.

In case of PREEMPT_RT or threadirqs, although the idle load balancing
may be inhibited in some cases on the ilb CPU, the fact that ksoftirqd
is the only fair task going back to sleep will trigger a newidle balance
on the CPU which will alleviate some imbalance if it exists if idle
balance fails to do so.

Fixes: b2a02fc43a1f ("smp: Optimize send_call_function_single_ipi()")
Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20241119054432.6405-4-kprateek.nayak@amd.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-17 13:24:33 +01:00
..
bpf bpf: fix OOB devmap writes when deleting elements 2024-12-17 13:24:29 +01:00
cgroup cgroup/bpf: only cgroup v2 can be attached by bpf programs 2024-12-17 13:24:02 +01:00
configs Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
debug kdb: Use the passed prompt in kdb_position_cursor() 2024-11-23 23:20:16 +01:00
dma dma-debug: fix a possible deadlock on radix_lock 2024-12-17 13:24:30 +01:00
entry Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
events Revert "uprobes: Use kzalloc to allocate xol area" 2024-11-24 00:23:37 +01:00
futex futex: Don't include process MM in futex key on no-MMU 2024-11-18 11:42:47 +01:00
gcov gcov: add support for GCC 14 2024-11-19 14:19:10 +01:00
irq genirq/irqdesc: Honor caller provided affinity in alloc_desc() 2024-11-23 23:20:29 +01:00
kcsan kcsan: Turn report_filterlist_lock into a raw_spinlock 2024-12-17 13:24:29 +01:00
livepatch kallsyms: refactor {,module_}kallsyms_on_each_symbol 2024-11-19 12:27:32 +01:00
locking Revert "rtmutex: Drop rt_mutex::wait_lock before scheduling" 2024-11-24 00:23:36 +01:00
power power/wakelock: Add a timeout to wakelocks globally 2024-11-19 18:06:07 +01:00
printk printk: Silence useless system log spam 2024-11-19 18:04:40 +01:00
rcu rcu-tasks: Idle tasks on offline CPUs are in quiescent states 2024-12-17 13:23:58 +01:00
sched sched/fair: Check idle_cpu() before need_resched() to detect ilb CPU turning busy 2024-12-17 13:24:33 +01:00
time time: Fix references to _msecs_to_jiffies() handling of values 2024-12-17 13:24:00 +01:00
trace tracing: Use atomic64_inc_return() in trace_clock_counter() 2024-12-17 13:24:31 +01:00
acct.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
async.c async: Introduce async_schedule_dev_nocall() 2024-11-18 12:12:56 +01:00
audit.c audit: Send netlink ACK before setting connection in auditd_set 2024-11-18 12:13:09 +01:00
audit.h Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
audit_fsnotify.c fsnotify: make allow_dups a property of the group 2024-11-19 12:27:55 +01:00
audit_tree.c fsnotify: pass flags argument to fsnotify_alloc_group() 2024-11-19 12:27:55 +01:00
audit_watch.c fsnotify: pass flags argument to fsnotify_alloc_group() 2024-11-19 12:27:55 +01:00
auditfilter.c ima: Avoid blocking in RCU read-side critical section 2024-11-19 14:19:42 +01:00
auditsc.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
backtracetest.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
bounds.c bounds: Use the right number of bits for power-of-two CONFIG_NR_CPUS 2024-11-19 11:32:40 +01:00
capability.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
cfi.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
compat.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
configs.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
context_tracking.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
cpu.c cpu: Silence log spam when a CPU is brought up 2024-11-19 18:04:55 +01:00
cpu_pm.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
crash_core.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
crash_dump.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
cred.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
delayacct.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
dma.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
exec_domain.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
exit.c mm: optimize the redundant loop of mm_update_owner_next() 2024-11-19 14:19:41 +01:00
extable.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
fail_function.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
fork.c exec: Simplify unshare_files 2024-11-19 12:27:27 +01:00
freezer.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
gen_kheaders.sh kheaders: explicitly define file modes for archived headers 2024-11-19 14:19:30 +01:00
groups.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
hung_task.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
iomem.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
irq_work.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
jump_label.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
kallsyms.c Revert "kallsyms: Make kallsyms_on_each_symbol generally available" 2024-11-24 00:22:59 +01:00
kcmp.c kcmp: In get_file_raw_ptr use task_lookup_fd_rcu 2024-11-19 12:27:27 +01:00
Kconfig.freezer Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
Kconfig.hz Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
Kconfig.locks Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
Kconfig.preempt Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
kcov.c kcov: don't lose track of remote references during softirqs 2024-11-19 14:19:10 +01:00
kexec.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
kexec_core.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
kexec_elf.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
kexec_file.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
kexec_internal.h Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
kheaders.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
kmod.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
kprobes.c Revert "x86/ibt,ftrace: Search for __fentry__ location" 2024-11-24 00:23:31 +01:00
ksysfs.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
kthread.c Revert "kthread: add kthread_work tracepoints" 2024-11-24 00:23:23 +01:00
latencytop.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
Makefile kernel: Use the stock defconfig for /proc/config.gz 2024-06-15 16:20:14 -03:00
module-internal.h Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
module.c Revert "kallsyms: Make module_kallsyms_on_each_symbol generally available" 2024-11-24 00:22:59 +01:00
module_signature.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
module_signing.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
notifier.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
nsproxy.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
padata.c Revert "padata: Honor the caller's alignment in case of chunk_size 0" 2024-11-24 00:23:30 +01:00
panic.c panic: Flush kernel log buffer at the end 2024-11-19 09:23:11 +01:00
params.c params: lift param_set_uint_minmax to common code 2024-11-19 12:27:09 +01:00
pid.c kernel/pid.c: implement additional checks upon pidfd_create() parameters 2024-11-19 12:27:43 +01:00
pid_namespace.c zap_pid_ns_processes: clear TIF_NOTIFY_SIGNAL along with TIF_SIGPENDING 2024-11-19 14:19:05 +01:00
profile.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
ptrace.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
range.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
reboot.c kernel/reboot: emergency_restart: Set correct system_state 2024-11-18 11:43:25 +01:00
regset.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
relay.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
resource.c Revert "resource: fix region_intersects() vs add_memory_driver_managed()" 2024-11-24 00:22:55 +01:00
rseq.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
scftorture.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
scs.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
seccomp.c seccomp: Invalidate seccomp mode to catch death failures 2024-11-18 22:25:35 +01:00
signal.c Revert "signal: Replace BUG_ON()s" 2024-11-24 00:23:07 +01:00
smp.c Revert "smp: Add missing destroy_work_on_stack() call in smp_call_on_cpu()" 2024-11-24 00:23:40 +01:00
smpboot.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
smpboot.h Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
softirq.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
stackleak.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
stacktrace.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
static_call.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
stop_machine.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
sys.c kernel/sys.c: implement custom uname override 2024-11-19 17:55:01 +01:00
sys_ni.c syscalls: fix compat_sys_io_pgetevents_time64 usage 2024-11-19 14:19:34 +01:00
sysctl-test.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
sysctl.c Revert "make sysctl constants read-only" 2024-12-03 19:57:26 +01:00
task_work.c task_work: Introduce task_work_cancel() again 2024-11-23 23:20:13 +01:00
taskstats.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
test_kprobes.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
torture.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
tracepoint.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
tsacct.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
ucount.c fanotify: configurable limits via sysfs 2024-11-19 12:27:37 +01:00
uid16.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
uid16.h Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
umh.c security: samsung: defex_lsm: nuke 2024-06-15 16:20:49 -03:00
up.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
user-return-notifier.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
user.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
user_namespace.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
usermode_driver.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
utsname.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
utsname_sysctl.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
watch_queue.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
watchdog.c watchdog: move softlockup_panic back to early_param 2024-11-18 11:43:21 +01:00
watchdog_hld.c watchdog/perf: properly initialize the turbo mode timestamp and rearm counter 2024-11-23 23:20:15 +01:00
workqueue.c Revert "workqueue: Make queue_rcu_work() use call_rcu_flush()" 2024-11-19 18:15:40 +01:00
workqueue_internal.h Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00