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

async: Fix lack of boot-time console due to insufficient synchronization

2009-06-08 12:31:53 -07:00

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

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

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_freezer.c

cgroups: let ss->can_attach and ss->attach do whole threadgroups at a time

2009-09-24 07:20:58 -07:00

cgroup.c

cgroup: fix strstrip() misuse

2009-10-29 07:39:25 -07:00

compat.c

signals: implement sys_rt_tgsigqueueinfo

2009-04-30 19:24:24 +02:00

configs.c

kernel/configs.c: remove useless comments

2008-10-20 08:52:34 -07:00

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: Inaugurate COW credentials

2008-11-14 10:39:23 +11:00

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

kernel/dma.c: remove a CVS keyword

2008-10-16 11:21:30 -07:00

exec_domain.c

Get rid of indirect include of fs_struct.h

2009-03-31 23:00:27 -04:00

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

Merge branch 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2009-04-05 11:04:19 -07:00

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_compat.c

futex: Fix compat_futex to be same as futex for REQUEUE_PI

2009-08-10 15:41:12 +02:00

futex.c

rtmutes: Convert rtmutex.lock to raw_spinlock

2009-12-14 23:55:33 +01:00

groups.c

groups: move code to kernel/groups.c

2009-06-16 19:47:48 -07:00

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

container freezer: implement freezer cgroup subsystem

2008-10-20 08:52:34 -07:00

Kconfig.hz

…

Kconfig.locks

mutex: Better control mutex adaptive spinning config

2009-12-03 11:50:11 +01:00

Kconfig.preempt

rcu: provide RCU options on non-preempt architectures too

2008-12-25 09:31:28 +01:00

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

sched, latencytop: incorporate review feedback from Andrew Morton

2009-02-11 10:18:04 +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

lockdep: move state bit definitions around

2009-02-14 23:27:59 +01:00

lockdep.c

locking: Convert __raw_spin* functions to arch_spin*

2009-12-14 23:55:32 +01:00

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

mutex: implement adaptive spinning

2009-01-14 18:09:02 +01:00

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

nsproxy: extract create_nsproxy()

2009-06-18 13:03:56 -07:00

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_namespace.c

pidns: deny CLONE_PARENT|CLONE_NEWPID combination

2009-09-24 07:21:04 -07:00

pid.c

pid: reduce code size by using a pointer to iterate over array

2009-12-16 07:20:12 -08:00

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_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

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

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_common.h

rt_mutex: add proxy lock routines

2009-04-06 11:14:02 +02:00

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

…

rwsem.c

…

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

sched: remove unused fields from struct rq

2009-03-24 23:16:51 +01:00

sched.c

sched: Convert pi_lock to raw_spinlock

2009-12-14 23:55:33 +01:00

seccomp.c

x86-64: seccomp: fix 32/64 syscall hole

2009-03-02 15:41:30 -08:00

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

stacktrace: provide save_stack_trace_tsk() weak alias

2008-12-25 11:44:43 +01:00

stop_machine.c

cpumask: remove cpumask_t from core

2009-03-30 22:05:17 +10:30

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

sys.c

kernel/sys.c: fix "warning: do-while statement is not a compound statement" noise

2009-12-15 08:53:26 -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

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

taskstats.c

genetlink: make netns aware

2009-07-12 14:03:27 -07:00

test_kprobes.c

kprobes: add tests for register_kprobes

2009-01-06 15:59:20 -08:00

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

Fix fixpoint divide exception in acct_update_integrals

2009-03-09 08:13:35 -07:00

uid16.c

headers: utsname.h redux

2009-09-23 18:13:10 -07:00

up.c

smp_call_function_single(): be slightly less stupid, fix #2

2009-01-12 16:04:37 +01:00

user_namespace.c

Fix recursive lock in free_uid()/free_user_ns()

2009-02-27 16:26:21 -08:00

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

utsname_sysctl.c

sysctl kernel: Remove binary sysctl logic

2009-11-12 02:04:55 -08:00

utsname.c

utsns: extract creeate_uts_ns()

2009-06-18 13:03:55 -07:00

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