linux/kernel
Eric W. Biederman 73c279927f kthread: don't depend on work queues
Currently there is a circular reference between work queue initialization
and kthread initialization.  This prevents the kthread infrastructure from
initializing until after work queues have been initialized.

We want the properties of tasks created with kthread_create to be as close
as possible to the init_task and to not be contaminated by user processes.
The later we start our kthreadd that creates these tasks the harder it is
to avoid contamination from user processes and the more of a mess we have
to clean up because the defaults have changed on us.

So this patch modifies the kthread support to not use work queues but to
instead use a simple list of structures, and to have kthreadd start from
init_task immediately after our kernel thread that execs /sbin/init.

By being a true child of init_task we only have to change those process
settings that we want to have different from init_task, such as our process
name, the cpus that are allowed, blocking all signals and setting SIGCHLD
to SIG_IGN so that all of our children are reaped automatically.

By being a true child of init_task we also naturally get our ppid set to 0
and do not wind up as a child of PID == 1.  Ensuring that tasks generated
by kthread_create will not slow down the functioning of the wait family of
functions.

[akpm@linux-foundation.org: use interruptible sleeps]
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:53 -07:00
..
irq Fix Linuxdoc comment 2007-05-09 12:30:48 -07:00
power PM: Separate hibernation code from suspend code 2007-05-09 12:30:48 -07:00
time Fix printk format warnings in timer_list.c 2007-05-09 12:30:50 -07:00
.gitignore gitignore: ignore more generated files 2006-01-03 11:35:26 +01:00
acct.c [PATCH] kernel: change uses of f_{dentry, vfsmnt} to use f_path 2006-12-08 08:28:42 -08:00
audit.c audit: add spaces on either side of case "..." operator. 2007-05-08 11:15:09 -07:00
audit.h [PATCH] audit: AUDIT_PERM support 2006-09-11 13:32:30 -04:00
auditfilter.c [PATCH] minor update to rule add/delete messages (ver 2) 2007-02-17 21:30:09 -05:00
auditsc.c [PATCH] fix deadlock in audit_log_task_context() 2007-03-14 15:27:48 -07:00
capability.c [PATCH] pid: replace do/while_each_task_pid with do/while_each_pid_task 2007-02-12 09:48:32 -08:00
compat.c [PATCH] Common compat_sys_sysinfo 2007-02-11 10:51:32 -08:00
configs.c use simple_read_from_buffer in kernel/ 2007-05-09 12:30:49 -07:00
cpu.c call cpu_chain with CPU_DOWN_FAILED if CPU_DOWN_PREPARE failed 2007-05-09 12:30:51 -07:00
cpuset.c use simple_read_from_buffer in kernel/ 2007-05-09 12:30:49 -07:00
delayacct.c KMEM_CACHE(): simplify slab cache creation 2007-05-07 12:12:55 -07:00
die_notifier.c move die notifier handling to common code 2007-05-08 11:15:04 -07:00
dma.c [PATCH] struct seq_operations and struct file_operations constification 2006-12-07 08:39:46 -08:00
exec_domain.c Remove obsolete #include <linux/config.h> 2006-06-30 19:25:36 +02:00
exit.c header cleaning: don't include smp_lock.h when not used 2007-05-08 11:15:07 -07:00
extable.c [PATCH] symbol_put_addr() locks kernel 2006-05-15 11:20:55 -07:00
fork.c header cleaning: don't include smp_lock.h when not used 2007-05-08 11:15:07 -07:00
futex_compat.c [PATCH] __user annotations: futex 2006-10-10 15:37:22 -07:00
futex.c futex: restartable futex_wait 2007-05-08 11:15:03 -07:00
hrtimer.c export hrtimer_forward 2007-05-08 11:15:15 -07:00
itimer.c The scheduled -EINVAL for invalid timevals in setitimer 2007-05-08 11:15:13 -07:00
kallsyms.c kallsyms: cleanup: use seq_release_private() where appropriate 2007-05-08 11:15:09 -07:00
Kconfig.hz [PATCH] HZ: 300Hz support 2006-12-07 08:39:36 -08:00
Kconfig.preempt [PATCH] sched: voluntary kernel preemption 2005-06-25 16:24:45 -07:00
kexec.c kdump/kexec: calculate note size at compile time 2007-05-08 11:15:07 -07:00
kfifo.c [PATCH] Numerous fixes to kernel-doc info in source files. 2007-02-11 10:51:32 -08:00
kmod.c ____call_usermodehelper: don't flush_signals() 2007-05-09 12:30:53 -07:00
kprobes.c Kprobes: The ON/OFF knob thru debugfs 2007-05-08 11:15:19 -07:00
ksysfs.c remove "struct subsystem" as it is no longer needed 2007-05-02 18:57:59 -07:00
kthread.c kthread: don't depend on work queues 2007-05-09 12:30:53 -07:00
latency.c [PATCH] severing module.h->sched.h 2006-12-04 02:00:22 -05:00
lockdep_internals.h [PATCH] lockdep: more chains 2006-12-07 08:39:43 -08:00
lockdep_proc.c [PATCH] remove many unneeded #includes of sched.h 2007-02-14 08:09:54 -08:00
lockdep.c lockdep: removed unused ip argument in mark_lock & mark_held_locks 2007-05-08 11:15:13 -07:00
Makefile move die notifier handling to common code 2007-05-08 11:15:04 -07:00
module.c Fix race between cat /proc/slab_allocators and rmmod 2007-05-08 11:15:08 -07:00
mutex-debug.c [PATCH] remove many unneeded #includes of sched.h 2007-02-14 08:09:54 -08:00
mutex-debug.h [PATCH] lockdep: better lock debugging 2006-07-03 15:27:01 -07:00
mutex.c [PATCH] lockdep: avoid lockdep warning in md 2006-12-08 08:28:39 -08:00
mutex.h [PATCH] lockdep: prove mutex locking correctness 2006-07-03 15:27:04 -07:00
nsproxy.c Merge sys_clone()/sys_unshare() nsproxy and namespace handling 2007-05-08 11:15:00 -07:00
panic.c [PATCH] Add TAINT_USER and ability to set taint flags from userspace 2007-02-11 10:51:29 -08:00
params.c kernel/params.c: fix lying comment for param_array() 2007-05-08 11:15:08 -07:00
pid.c Merge sys_clone()/sys_unshare() nsproxy and namespace handling 2007-05-08 11:15:00 -07:00
posix-cpu-timers.c Introduce a handy list_first_entry macro 2007-05-08 11:15:11 -07:00
posix-timers.c header cleaning: don't include smp_lock.h when not used 2007-05-08 11:15:07 -07:00
printk.c header cleaning: don't include smp_lock.h when not used 2007-05-08 11:15:07 -07:00
profile.c [PATCH] proc: remove useless (and buggy) ->nlink settings 2007-02-11 10:51:32 -08:00
ptrace.c [PATCH] pidspace: is_init() 2006-09-29 09:18:12 -07:00
rcupdate.c [PATCH] rcu: add a prefetch() in rcu_do_batch() 2006-12-07 08:39:40 -08:00
rcutorture.c rcutorture: Remove redundant assignment to cur_ops in for loop 2007-05-08 11:15:17 -07:00
relay.c relay: use plain timer instead of delayed work 2007-05-09 12:30:51 -07:00
resource.c libata/IDE: remove combined mode quirk 2007-04-28 14:15:59 -04:00
rtmutex_common.h [PATCH] pi-futex: futex_lock_pi/futex_unlock_pi support 2006-06-27 17:32:47 -07:00
rtmutex-debug.c Remove all inclusions of <linux/config.h> 2006-10-04 03:38:54 -04:00
rtmutex-debug.h [PATCH] lockdep: better lock debugging 2006-07-03 15:27:01 -07:00
rtmutex-tester.c [PATCH] Add include/linux/freezer.h and move definitions from sched.h 2006-12-07 08:39:27 -08:00
rtmutex.c [PATCH] hrtimers: namespace and enum cleanup 2007-02-16 08:13:58 -08:00
rtmutex.h [PATCH] lockdep: better lock debugging 2006-07-03 15:27:01 -07:00
rwsem.c Lockdep treats down_write_trylock like regular down_write 2007-05-08 11:15:09 -07:00
sched.c Eliminate lock_cpu_hotplug in kernel/schedc 2007-05-09 12:30:51 -07:00
seccomp.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
signal.c zap_other_threads: remove unneeded ->exit_signal change 2007-05-09 12:30:53 -07:00
softirq.c [PATCH] tick-management: dyntick / highres functionality 2007-02-16 08:13:59 -08:00
softlockup.c add touch_all_softlockup_watchdogs() 2007-05-08 11:15:06 -07:00
spinlock.c [PATCH] lockdep: spin_lock_irqsave_nested() 2006-11-25 13:28:34 -08:00
srcu.c [PATCH] SRCU: report out-of-memory errors 2006-10-04 07:55:30 -07:00
stacktrace.c [PATCH] lockdep: stacktrace subsystem, core 2006-07-03 15:27:02 -07:00
stop_machine.c Use stop_machine_run in the Intel RNG driver 2007-05-08 11:15:00 -07:00
sys_ni.c [PATCH] Create compat_sys_migrate_pages 2006-11-03 12:27:59 -08:00
sys.c Extend notifier_call_chain to count nr_calls made 2007-05-09 12:30:51 -07:00
sysctl.c proc: maps protection 2007-05-08 11:15:02 -07:00
taskstats.c KMEM_CACHE(): simplify slab cache creation 2007-05-07 12:12:55 -07:00
time.c header cleaning: don't include smp_lock.h when not used 2007-05-08 11:15:07 -07:00
timer.c Introduce a handy list_first_entry macro 2007-05-08 11:15:11 -07:00
tsacct.c [PATCH] time: x86_64: split x86_64/kernel/time.c up 2007-02-16 08:14:00 -08:00
uid16.c header cleaning: don't include smp_lock.h when not used 2007-05-08 11:15:07 -07:00
user.c [PATCH] slab: remove kmem_cache_t 2006-12-07 08:39:25 -08:00
utsname_sysctl.c [PATCH] sysctl: remove insert_at_head from register_sysctl 2007-02-14 08:09:59 -08:00
utsname.c Merge sys_clone()/sys_unshare() nsproxy and namespace handling 2007-05-08 11:15:00 -07:00
wait.c [PATCH] uninline init_waitqueue_head() 2006-07-10 13:24:25 -07:00
workqueue.c unify flush_work/flush_work_keventd and rename it to cancel_work_sync 2007-05-09 12:30:53 -07:00