Oleg Nesterov 9cd80bbb07 do_wait() optimization: do not place sub-threads on task_struct->children list ... Thanks to Roland who pointed out de_thread() issues. Currently we add sub-threads to ->real_parent->children list. This buys nothing but slows down do_wait(). With this patch ->children contains only main threads (group leaders). The only complication is that forget_original_parent() should iterate over sub-threads by hand, and de_thread() needs another list_replace() when it changes ->group_leader. Henceforth do_wait_thread() can never see task_detached() && !EXIT_DEAD tasks, we can remove this check (and we can unify do_wait_thread() and ptrace_do_wait()). This change can confuse the optimistic search in mm_update_next_owner(), but this is fixable and minor. Perhaps badness() and oom_kill_process() should be updated, but they should be fixed in any case. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Roland McGrath <roland@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Ratan Nalumasu <rnalumasu@gmail.com> Cc: Vitaly Mayatskikh <vmayatsk@redhat.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2009-12-17 15:45:31 -08:00
..
gcov	microblaze: Enable GCOV_PROFILE_ALL	2009-09-21 14:29:21 +02:00
irq	genirq: Convert irq_desc.lock to raw_spinlock	2009-12-14 23:55:33 +01:00
power	vt: introduce and use vt_kmsg_redirect() function	2009-12-15 08:53:28 -08:00
time	timecompare: fix half-Y2K38 problem in timecompare_update while calculating offset	2009-12-16 07:19:57 -08:00
trace	Merge branch 'for-33' of git://repo.or.cz/linux-kbuild	2009-12-17 07:23:42 -08:00
.gitignore
acct.c	bsdacct: fix uid/gid misreporting	2009-12-15 08:53:10 -08:00
async.c
audit.c	Audit: send signal info if selinux is disabled	2009-09-24 03:50:26 -04:00
audit.h	Fix rule eviction order for AUDIT_DIR	2009-06-24 00:02:38 -04:00
audit_tree.c	Fix rule eviction order for AUDIT_DIR	2009-06-24 00:02:38 -04:00
audit_watch.c	Audit: reorganize struct audit_watch to save 8 bytes	2009-09-24 03:50:25 -04:00
auditfilter.c	Audit: clean up all op= output to include string quoting	2009-06-24 00:00:52 -04:00
auditsc.c	Audit: rearrange audit_context to save 16 bytes per struct	2009-09-24 03:50:26 -04:00
backtracetest.c
bounds.c	kbuild: move bounds.h to include/generated	2009-12-12 13:08:14 +01:00
capability.c	remove CONFIG_SECURITY_FILE_CAPABILITIES compile option	2009-11-24 15:06:47 +11:00
cgroup.c	cgroup: fix strstrip() misuse	2009-10-29 07:39:25 -07:00
cgroup_freezer.c	cgroups: let ss->can_attach and ss->attach do whole threadgroups at a time	2009-09-24 07:20:58 -07:00
compat.c
configs.c
cpu.c	Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2009-12-12 11:34:10 -08:00
cpuset.c	sched: Fix balance vs hotplug race	2009-12-06 21:10:56 +01:00
cred-internals.h
cred.c	creds_are_invalid() needs to be exported for use by modules:	2009-09-23 11:02:26 -07:00
delayacct.c	headers: taskstats_kern.h trim	2009-09-18 09:48:52 -07:00
dma.c
exec_domain.c
exit.c	do_wait() optimization: do not place sub-threads on task_struct->children list	2009-12-17 15:45:31 -08:00
extable.c
fork.c	do_wait() optimization: do not place sub-threads on task_struct->children list	2009-12-17 15:45:31 -08:00
freezer.c	sched: fix nr_uninterruptible accounting of frozen tasks really	2009-07-18 14:19:53 +02:00
futex.c	rtmutes: Convert rtmutex.lock to raw_spinlock	2009-12-14 23:55:33 +01:00
futex_compat.c	futex: Fix compat_futex to be same as futex for REQUEUE_PI	2009-08-10 15:41:12 +02:00
groups.c
hrtimer.c	hrtimers: Convert to raw_spinlocks	2009-12-14 23:55:34 +01:00
hung_task.c	softlockup: Fix hung_task_check_count sysctl	2009-11-27 06:21:57 +01:00
hw_breakpoint.c	perf_event: Convert to raw_spinlock	2009-12-14 23:55:34 +01:00
itimer.c	itimers: Fix racy writes to cpu_itimer fields	2009-11-18 16:32:12 +01:00
kallsyms.c	hw-breakpoints: Fix broken hw-breakpoint sample module	2009-11-10 11:23:29 +01:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks	mutex: Better control mutex adaptive spinning config	2009-12-03 11:50:11 +01:00
Kconfig.preempt
kexec.c	Merge branch 'for-33' of git://repo.or.cz/linux-kbuild	2009-12-17 07:23:42 -08:00
kfifo.c	kfifo: Use "const" definitions	2009-09-19 13:13:17 -07:00
kgdb.c	kgdb: Always process the whole breakpoint list on activate or deactivate	2009-12-11 08:43:20 -06:00
kmod.c	security: report the module name to security_module_request	2009-11-10 09:33:46 +11:00
kprobes.c	Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2009-12-05 15:30:21 -08:00
ksysfs.c	kexec: premit reduction of the reserved memory size	2009-12-16 07:20:13 -08:00
kthread.c	sched: Fix kthread_bind() by moving the body of kthread_bind() to sched.c	2009-11-03 07:25:00 +01:00
latencytop.c
lockdep.c	locking: Convert __raw_spin* functions to arch_spin*	2009-12-14 23:55:32 +01:00
lockdep_internals.h	lockdep: BFS cleanup	2009-07-24 10:53:29 +02:00
lockdep_proc.c	seq_file: constify seq_operations	2009-09-23 07:39:29 -07:00
lockdep_states.h
Makefile	Merge branch 'kvm-updates/2.6.33' of git://git.kernel.org/pub/scm/virt/kvm/kvm	2009-12-08 08:02:38 -08:00
module.c	module: handle ppc64 relocating kcrctabs when CONFIG_RELOCATABLE=y	2009-12-15 16:28:34 +10:30
mutex-debug.c	headers: remove sched.h from interrupt.h	2009-10-11 11:20:58 -07:00
mutex-debug.h	locking: Implement new raw_spinlock	2009-12-14 23:55:32 +01:00
mutex.c	mutex: Better control mutex adaptive spinning config	2009-12-03 11:50:11 +01:00
mutex.h
notifier.c	kprobes: Fix to add __kprobes to notify_die	2009-08-30 03:08:26 +02:00
ns_cgroup.c	cgroups: let ss->can_attach and ss->attach do whole threadgroups at a time	2009-09-24 07:20:58 -07:00
nsproxy.c
panic.c	Merge git://git.infradead.org/mtd-2.6	2009-12-16 10:23:43 -08:00
params.c	tree-wide: convert open calls to remove spaces to skip_spaces() lib function	2009-12-15 08:53:32 -08:00
perf_event.c	Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2009-12-16 12:32:47 -08:00
pid.c	pid: reduce code size by using a pointer to iterate over array	2009-12-16 07:20:12 -08:00
pid_namespace.c	pidns: deny CLONE_PARENT|CLONE_NEWPID combination	2009-09-24 07:21:04 -07:00
pm_qos_params.c	pm_qos: clean up racy global "name" variable	2009-10-14 15:31:10 +02:00
posix-cpu-timers.c	posix-cpu-timers: optimize and document timer_create callback	2009-11-18 12:36:05 +01:00
posix-timers.c	time: Introduce CLOCK_REALTIME_COARSE	2009-08-21 21:43:46 +02:00
printk.c	Merge git://git.infradead.org/mtd-2.6	2009-12-16 10:23:43 -08:00
profile.c	kernel/profile.c: Switch /proc/irq/prof_cpu_mask to seq_file	2009-09-20 20:15:40 +02:00
ptrace.c	ptrace: __ptrace_detach: do __wake_up_parent() if we reap the tracee	2009-09-24 07:20:59 -07:00
rcupdate.c	rcu: Re-arrange code to reduce #ifdef pain	2009-11-22 18:58:16 +01:00
rcutiny.c	rcu: Eliminate unneeded function wrapping	2009-11-22 18:58:16 +01:00
rcutorture.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu	2009-12-14 09:58:24 -08:00
rcutree.c	rcu: Add expedited grace-period support for preemptible RCU	2009-12-03 11:35:25 +01:00
rcutree.h	rcu: Add expedited grace-period support for preemptible RCU	2009-12-03 11:35:25 +01:00
rcutree_plugin.h	rcu: Add expedited grace-period support for preemptible RCU	2009-12-03 11:35:25 +01:00
rcutree_trace.c	rcu: Add expedited grace-period support for preemptible RCU	2009-12-03 11:35:25 +01:00
relay.c	const: constify remaining pipe_buf_operations	2009-12-16 07:20:05 -08:00
res_counter.c	memcg: some modification to softlimit under hierarchical memory reclaim.	2009-10-01 16:11:13 -07:00
resource.c	resources: when allocate_resource() fails, leave resource untouched	2009-11-04 13:06:46 -08:00
rtmutex-debug.c	sched: Convert pi_lock to raw_spinlock	2009-12-14 23:55:33 +01:00
rtmutex-debug.h
rtmutex-tester.c
rtmutex.c	rtmutes: Convert rtmutex.lock to raw_spinlock	2009-12-14 23:55:33 +01:00
rtmutex.h
rtmutex_common.h
rwsem.c
sched.c	sched: Convert pi_lock to raw_spinlock	2009-12-14 23:55:33 +01:00
sched_clock.c	sched_clock: Fix atomicity/continuity bug by using cmpxchg64()	2009-09-30 22:56:10 +02:00
sched_cpupri.c	sched: Convert cpupri lock to raw_spinlock	2009-12-14 23:55:33 +01:00
sched_cpupri.h	sched: Convert cpupri lock to raw_spinlock	2009-12-14 23:55:33 +01:00
sched_debug.c	sched: Convert rq->lock to raw_spinlock	2009-12-14 23:55:33 +01:00
sched_fair.c	sched: Convert rq->lock to raw_spinlock	2009-12-14 23:55:33 +01:00
sched_features.h	sched: Discard some old bits	2009-12-09 10:03:07 +01:00
sched_idletask.c	sched: Convert rq->lock to raw_spinlock	2009-12-14 23:55:33 +01:00
sched_rt.c	sched: Convert rt_runtime_lock to raw_spinlock	2009-12-14 23:55:33 +01:00
sched_stats.h
seccomp.c
semaphore.c
signal.c	signals: check ->group_stop_count after tracehook_get_signal()	2009-12-16 07:20:09 -08:00
slow-work-debugfs.c	SLOW_WORK: Move slow_work's proc file to debugfs	2009-12-01 08:20:31 -08:00
slow-work.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/sysctl-2.6	2009-12-08 07:38:50 -08:00
slow-work.h	SLOW_WORK: Move slow_work's proc file to debugfs	2009-12-01 08:20:31 -08:00
smp.c	Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2009-12-15 09:02:01 -08:00
softirq.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu	2009-12-14 09:58:24 -08:00
softlockup.c	percpu: make percpu symbols under kernel/ and mm/ unique	2009-10-29 22:34:13 +09:00
spinlock.c	locking: Cleanup the name space completely	2009-12-14 23:55:33 +01:00
srcu.c	rcu: Add synchronize_srcu_expedited()	2009-10-26 09:40:30 +01:00
stacktrace.c
stop_machine.c
sys.c	kernel/sys.c: fix "warning: do-while statement is not a compound statement" noise	2009-12-15 08:53:26 -08:00
sys_ni.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6	2009-12-08 07:55:01 -08:00
sysctl.c	kernel/sysctl.c: fix the incomplete part of sysctl_max_map_count-should-be-non-negative.patch	2009-12-17 15:45:30 -08:00
sysctl_binary.c	[sysctl] Fix breakage on systems with older glibc	2009-12-16 12:36:18 -08:00
sysctl_check.c	ipv4 05/05: add sysctl to accept packets with local source addresses	2009-12-03 12:14:38 -08:00
taskstats.c	genetlink: make netns aware	2009-07-12 14:03:27 -07:00
test_kprobes.c
time.c	Merge branch 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2009-12-08 19:27:08 -08:00
timeconst.pl
timer.c	Merge branch 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2009-09-23 09:46:15 -07:00
tracepoint.c	trivial: fix typo "to to" in multiple files	2009-09-21 15:14:55 +02:00
tsacct.c
uid16.c	headers: utsname.h redux	2009-09-23 18:13:10 -07:00
up.c
user-return-notifier.c	core: Clean up user return notifers use of per_cpu	2009-12-02 10:22:59 +01:00
user.c	uids: Prevent tear down race	2009-11-02 16:02:39 +01:00
user_namespace.c
utsname.c
utsname_sysctl.c	sysctl kernel: Remove binary sysctl logic	2009-11-12 02:04:55 -08:00
wait.c	locking, sched: Give waitqueue spinlocks their own lockdep classes	2009-08-10 14:43:09 +02:00
workqueue.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq	2009-12-10 09:35:44 -08:00