Petr Mladek ebb2bdcef8 kthread_worker: document CPU hotplug handling ... The kthread worker API is simple. In short, it allows to create, use, and destroy workers. kthread_create_worker_on_cpu() just allows to bind a newly created worker to a given CPU. It is up to the API user how to handle CPU hotplug. They have to decide how to handle pending work items, prevent queuing new ones, and restore the functionality when the CPU goes off and on. There are few catches: + The CPU affinity gets lost when it is scheduled on an offline CPU. + The worker might not exist when the CPU was off when the user created the workers. A good practice is to implement two CPU hotplug callbacks and destroy/create the worker when CPU goes down/up. Mention this in the function description. [akpm@linux-foundation.org: grammar tweaks] Link: https://lore.kernel.org/r/20201028073031.4536-1-qiang.zhang@windriver.com Link: https://lkml.kernel.org/r/20201102101039.19227-1-pmladek@suse.com Reported-by: Zhang Qiang <Qiang.Zhang@windriver.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2020-12-15 12:13:36 -08:00
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bpf	bpf: Fix enum names for bpf_this_cpu_ptr() and bpf_per_cpu_ptr() helpers	2020-12-11 14:19:07 -08:00
cgroup	kernel/: fix repeated words in comments	2020-10-16 11:11:19 -07:00
configs	…
debug	…
dma	swiotlb: remove the tbl_dma_addr argument to swiotlb_tbl_map_single	2020-11-02 10:10:39 -05:00
entry	entry: Fix the incorrect ordering of lockdep and RCU check	2020-11-04 18:06:14 +01:00
events	perf: Tweak perf_event_attr::exclusive semantics	2020-11-09 18:12:36 +01:00
gcov	…
irq	genirq/irqdomain: Add an irq_create_mapping_affinity() function	2020-11-30 12:21:31 +01:00
kcsan	kernel/: fix repeated words in comments	2020-10-16 11:11:19 -07:00
livepatch	kernel/: fix repeated words in comments	2020-10-16 11:11:19 -07:00
locking	lockdep: Put graph lock/unlock under lock_recursion protection	2020-11-17 13:15:35 +01:00
power	PM: sleep: fix typo in kernel/power/process.c	2020-10-27 19:11:44 +01:00
printk	Urgent printk fix for 5.10	2020-11-27 10:38:36 -08:00
rcu	Merge branch 'urgent-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu	2020-11-17 10:31:56 -08:00
sched	membarrier: Execute SYNC_CORE on the calling thread	2020-12-09 09:37:43 +01:00
time	time: Prevent undefined behaviour in timespec64_to_ns()	2020-10-26 11:48:11 +01:00
trace	bpf: Fix enum names for bpf_this_cpu_ptr() and bpf_per_cpu_ptr() helpers	2020-12-11 14:19:07 -08:00
.gitignore	…
Kconfig.freezer	…
Kconfig.hz	…
Kconfig.locks	…
Kconfig.preempt	…
Makefile	elfcore: fix building with clang	2020-12-11 14:02:14 -08:00
acct.c	kernel: acct.c: fix some kernel-doc nits	2020-10-16 11:11:19 -07:00
async.c	…
audit.c	…
audit.h	…
audit_fsnotify.c	…
audit_tree.c	…
audit_watch.c	…
auditfilter.c	…
auditsc.c	…
backtracetest.c	…
bounds.c	…
capability.c	LSM: Signal to SafeSetID when setting group IDs	2020-10-13 09:17:34 -07:00
compat.c	…
configs.c	…
context_tracking.c	…
cpu.c	kernel/cpu: add arch override for clear_tasks_mm_cpumask() mm handling	2020-11-27 00:10:39 +11:00
cpu_pm.c	…
crash_core.c	…
crash_dump.c	…
cred.c	…
delayacct.c	…
dma.c	…
exec_domain.c	…
exit.c	don't dump the threads that had been already exiting when zapped.	2020-10-28 16:39:49 -04:00
extable.c	…
fail_function.c	fail_function: Remove a redundant mutex unlock	2020-11-19 11:58:16 -08:00
fork.c	fork: fix copy_process(CLONE_PARENT) race with the exiting ->real_parent	2020-11-08 11:18:39 -08:00
freezer.c	…
futex.c	futex: Don't enable IRQs unconditionally in put_pi_state()	2020-11-09 14:30:30 +01:00
gen_kheaders.sh	…
groups.c	LSM: Signal to SafeSetID when setting group IDs	2020-10-13 09:17:34 -07:00
hung_task.c	kernel/hung_task.c: make type annotations consistent	2020-11-02 12:14:19 -08:00
iomem.c	…
irq_work.c	…
jump_label.c	kernel/: fix repeated words in comments	2020-10-16 11:11:19 -07:00
kallsyms.c	treewide: Convert macro and uses of __section(foo) to __section("foo")	2020-10-25 14:51:49 -07:00
kcmp.c	…
kcov.c	…
kexec.c	…
kexec_core.c	kernel/: fix repeated words in comments	2020-10-16 11:11:19 -07:00
kexec_elf.c	…
kexec_file.c	kernel/resource: move and rename IORESOURCE_MEM_DRIVER_MANAGED	2020-10-16 11:11:18 -07:00
kexec_internal.h	…
kheaders.c	…
kmod.c	…
kprobes.c	kprobes: Tell lockdep about kprobe nesting	2020-11-04 09:46:06 -05:00
ksysfs.c	…
kthread.c	kthread_worker: document CPU hotplug handling	2020-12-15 12:13:36 -08:00
latencytop.c	…
module-internal.h	…
module.c	Modules updates for v5.10	2020-10-22 13:08:57 -07:00
module_signature.c	…
module_signing.c	…
notifier.c	…
nsproxy.c	…
padata.c	…
panic.c	panic: don't dump stack twice on warn	2020-11-14 11:26:04 -08:00
params.c	params: Replace zero-length array with flexible-array member	2020-10-29 17:22:59 -05:00
pid.c	pid: move pidfd_get_pid() to pid.c	2020-10-18 09:27:10 -07:00
pid_namespace.c	kernel/: fix repeated words in comments	2020-10-16 11:11:19 -07:00
profile.c	…
ptrace.c	ptrace: Set PF_SUPERPRIV when checking capability	2020-11-17 12:53:22 -08:00
range.c	kernel.h: split out min()/max() et al. helpers	2020-10-16 11:11:19 -07:00
reboot.c	reboot: fix overflow parsing reboot cpu number	2020-11-14 11:26:03 -08:00
regset.c	…
relay.c	kernel/relay.c: drop unneeded initialization	2020-10-16 11:11:22 -07:00
resource.c	kernel/resource: make iomem_resource implicit in release_mem_region_adjustable()	2020-10-16 11:11:18 -07:00
rseq.c	…
scftorture.c	…
scs.c	…
seccomp.c	seccomp: Set PF_SUPERPRIV when checking capability	2020-11-17 12:53:22 -08:00
signal.c	ptrace: fix task_join_group_stop() for the case when current is traced	2020-11-02 12:14:19 -08:00
smp.c	Merge tag 'core-rcu-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2020-10-18 14:34:50 -07:00
smpboot.c	…
smpboot.h	…
softirq.c	…
stackleak.c	…
stacktrace.c	…
static_call.c	…
stop_machine.c	stop_machine, rcu: Mark functions as notrace	2020-10-26 12:12:27 +01:00
sys.c	kernel/sys.c: fix prototype of prctl_get_tid_address()	2020-10-25 11:44:16 -07:00
sys_ni.c	mm/madvise: introduce process_madvise() syscall: an external memory hinting API	2020-10-18 09:27:10 -07:00
sysctl-test.c	…
sysctl.c	…
task_work.c	task_work: cleanup notification modes	2020-10-17 15:05:30 -06:00
taskstats.c	…
test_kprobes.c	…
torture.c	…
tracepoint.c	tracepoint: Replace zero-length array with flexible-array member	2020-10-29 17:22:59 -05:00
tsacct.c	…
ucount.c	…
uid16.c	…
uid16.h	…
umh.c	…
up.c	…
user-return-notifier.c	…
user.c	…
user_namespace.c	kernel/: fix repeated words in comments	2020-10-16 11:11:19 -07:00
usermode_driver.c	…
utsname.c	…
utsname_sysctl.c	…
watch_queue.c	…
watchdog.c	kernel/watchdog: fix watchdog_allowed_mask not used warning	2020-11-14 11:26:03 -08:00
watchdog_hld.c	…
workqueue.c	workqueue: fix a kernel-doc warning	2020-10-16 07:28:20 +02:00
workqueue_internal.h	…