Oleg Nesterov c7e49c1488 ptrace: optimize exit_ptrace() for the likely case ... exit_ptrace() takes tasklist_lock unconditionally. We need this lock to avoid the race with ptrace_traceme(), it acts as a barrier. Change its caller, forget_original_parent(), to call exit_ptrace() under tasklist_lock. Change exit_ptrace() to drop and reacquire this lock if needed. This allows us to add the fastpath list_empty(ptraced) check. In the likely no-tracees case exit_ptrace() just returns and we avoid the lock() + unlock() sequence. "Zhang, Yanmin" <yanmin_zhang@linux.intel.com> suggested to add this check, and he reports that this change adds about 11% improvement in some tests. Suggested-and-tested-by: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2010-08-11 08:59:19 -07:00
..
debug	Merge branch 'timers-timekeeping-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2010-08-06 13:18:29 -07:00
gcov
irq	irq: Add new IRQ flag IRQF_NO_SUSPEND	2010-07-29 13:24:57 +02:00
power	Merge branch 'for-2.6.36' of git://git.kernel.dk/linux-2.6-block	2010-08-10 15:22:42 -07:00
time	Merge branch 'timers-timekeeping-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2010-08-06 13:18:29 -07:00
trace	Merge branch 'for-2.6.36' of git://git.kernel.dk/linux-2.6-block	2010-08-10 15:22:42 -07:00
.gitignore
acct.c	pass a struct path to vfs_statfs	2010-08-09 16:48:42 -04:00
async.c
audit_tree.c	fanotify: use both marks when possible	2010-07-28 10:18:55 -04:00
audit_watch.c	fanotify: use both marks when possible	2010-07-28 10:18:55 -04:00
audit.c	Merge branch 'for-linus' of git://git.infradead.org/users/eparis/notify	2010-08-10 11:39:13 -07:00
audit.h	Audit: split audit watch Kconfig	2010-07-28 09:58:19 -04:00
auditfilter.c	audit: do not get and put just to free a watch	2010-07-28 09:58:17 -04:00
auditsc.c	fsnotify: rename fsnotify_mark_entry to just fsnotify_mark	2010-07-28 09:58:53 -04:00
backtracetest.c
bounds.c
capability.c
cgroup_freezer.c
cgroup.c	cgroups: save space for the terminator	2010-08-11 08:59:18 -07:00
compat.c
configs.c
cpu.c
cpuset.c	Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2010-08-06 09:39:22 -07:00
cred.c	CRED: Fix get_task_cred() and task_state() to not resurrect dead credentials	2010-07-29 15:16:17 -07:00
delayacct.c
dma.c
early_res.c
elfcore.c
exec_domain.c	sys_personality: remove the bogus checks in sys_personality()->__set_personality() path	2010-08-09 20:45:05 -07:00
exit.c	ptrace: optimize exit_ptrace() for the likely case	2010-08-11 08:59:19 -07:00
extable.c
fork.c	oom: badness heuristic rewrite	2010-08-09 20:45:02 -07:00
freezer.c
futex_compat.c
futex.c
groups.c
hrtimer.c	Merge branch 'timers-timekeeping-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2010-08-06 13:18:29 -07:00
hung_task.c
hw_breakpoint.c	Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2010-08-06 09:30:52 -07:00
itimer.c
kallsyms.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kexec.c
kfifo.c
kmod.c
kprobes.c
ksysfs.c
kthread.c
latencytop.c
lockdep_internals.h
lockdep_proc.c
lockdep_states.h
lockdep.c
Makefile	Merge branch 'for-linus' of git://git.infradead.org/users/eparis/notify	2010-08-10 11:39:13 -07:00
module.c	module: cleanup comments, remove noinline	2010-08-05 12:59:13 +09:30
mutex-debug.c
mutex-debug.h
mutex.c
mutex.h
notifier.c
ns_cgroup.c
nsproxy.c
padata.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6	2010-08-04 15:23:14 -07:00
panic.c
params.c
perf_event.c	Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2010-08-06 09:39:22 -07:00
pid_namespace.c
pid.c
pm_qos_params.c
posix-cpu-timers.c	Merge branch 'writable_limits' of git://decibel.fi.muni.cz/~xslaby/linux	2010-08-10 12:07:51 -07:00
posix-timers.c	posix_timer: Move copy_to_user(created_timer_id) down in timer_create()	2010-07-23 15:08:12 +02:00
printk.c	gcc-4.6: printk: use stable variable to dump kmsg buffer	2010-08-09 20:45:06 -07:00
profile.c
ptrace.c	ptrace: optimize exit_ptrace() for the likely case	2010-08-11 08:59:19 -07:00
range.c	kernel/range: remove unused definition of ARRAY_SIZE()	2010-08-09 20:45:06 -07:00
rcupdate.c
rcutiny_plugin.h
rcutiny.c
rcutorture.c
rcutree_plugin.h
rcutree_trace.c
rcutree.c
rcutree.h
relay.c
res_counter.c
resource.c
rtmutex_common.h
rtmutex-debug.c
rtmutex-debug.h
rtmutex-tester.c
rtmutex.c
rtmutex.h
rwsem.c
sched_clock.c
sched_cpupri.c
sched_cpupri.h
sched_debug.c	sched: Use correct macro to display sched_child_runs_first in /proc/sched_debug	2010-07-21 21:46:12 +02:00
sched_fair.c	Merge branch 'linus' into sched/core	2010-07-21 21:45:08 +02:00
sched_features.h
sched_idletask.c
sched_rt.c
sched_stats.h
sched.c	Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2010-08-06 09:39:22 -07:00
seccomp.c
semaphore.c
signal.c	CRED: Fix RCU warning due to previous patch fixing __task_cred()'s checks	2010-08-04 11:17:10 -07:00
smp.c
softirq.c
spinlock.c
srcu.c
stacktrace.c
stop_machine.c	stop_machine: struct cpu_stopper, remove alignment padding on 64 bits	2010-08-09 20:45:06 -07:00
sys_ni.c	fanotify: sys_fanotify_mark declartion	2010-07-28 09:58:55 -04:00
sys.c
sysctl_binary.c
sysctl_check.c
sysctl.c	Merge branch 'for-linus' of git://git.infradead.org/users/eparis/notify	2010-08-10 11:39:13 -07:00
taskstats.c
test_kprobes.c
time.c	time: Kill off CONFIG_GENERIC_TIME	2010-07-27 12:40:54 +02:00
timeconst.pl
timer.c	kernel/timer.c: fix kernel-doc function parameter warning	2010-08-10 15:33:09 -07:00
tracepoint.c
tsacct.c
uid16.c
up.c
user_namespace.c
user-return-notifier.c
user.c
utsname_sysctl.c
utsname.c
wait.c
watchdog.c
workqueue_sched.h
workqueue.c	workqueue: workqueue_cpu_callback() should be cpu_notifier instead of hotcpu_notifier	2010-08-09 11:50:34 +02:00