Repository files (latest commit first)

Filename	Latest commit message	Latest commit date
Pavel Emelyanov cf7b708c8d Make access to task's nsproxy lighter ... When someone wants to deal with some other taks's namespaces it has to lock the task and then to get the desired namespace if the one exists. This is slow on read-only paths and may be impossible in some cases. E.g. Oleg recently noticed a race between unshare() and the (sent for review in cgroups) pid namespaces - when the task notifies the parent it has to know the parent's namespace, but taking the task_lock() is impossible there - the code is under write locked tasklist lock. On the other hand switching the namespace on task (daemonize) and releasing the namespace (after the last task exit) is rather rare operation and we can sacrifice its speed to solve the issues above. The access to other task namespaces is proposed to be performed like this: rcu_read_lock(); nsproxy = task_nsproxy(tsk); if (nsproxy != NULL) { / * * work with the namespaces here * e.g. get the reference on one of them * / } / * * NULL task_nsproxy() means that this task is * almost dead (zombie) * / rcu_read_unlock(); This patch has passed the review by Eric and Oleg :) and, of course, tested. [clg@fr.ibm.com: fix unshare()] [ebiederm@xmission.com: Update get_net_ns_by_pid] Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Cedric Le Goater <clg@fr.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2007-10-19 11:53:37 -07:00
..
irq	Compile handle_percpu_irq even for uniprocessor kernels	2007-10-17 08:43:00 -07:00
power	Hibernation: Enter platform hibernation state in a consistent way	2007-10-18 14:37:20 -07:00
time	x86: C1E late detection fix. Really switch off lapic timer	2007-10-17 20:15:13 +02:00
.gitignore
acct.c	whitespace fixes: process accounting	2007-10-18 14:37:24 -07:00
audit.c	whitespace fixes: system auditing	2007-10-18 14:37:25 -07:00
audit.h
auditfilter.c	whitespace fixes: audit filtering	2007-10-18 14:37:24 -07:00
auditsc.c	whitespace fixes: syscall auditing	2007-10-18 14:37:25 -07:00
capability.c	pid namespaces: define is_global_init() and is_container_init()	2007-10-19 11:53:37 -07:00
cgroup.c	Add cgroupstats	2007-10-19 11:53:36 -07:00
cgroup_debug.c	Task Control Groups: simple task cgroup debug info subsystem	2007-10-19 11:53:36 -07:00
compat.c	Merge ssh://master.kernel.org/pub/scm/linux/kernel/git/tglx/linux-2.6-hrt	2007-10-18 15:12:41 -07:00
configs.c
cpu.c	cpu hotplug: cpu: deliver CPU_UP_CANCELED only to NOTIFY_OKed callbacks with CPU_UP_PREPARE	2007-10-18 14:37:21 -07:00
cpu_acct.c	Task Control Groups: example CPU accounting subsystem	2007-10-19 11:53:36 -07:00
cpuset.c	Task Control Groups: make cpusets a client of cgroups	2007-10-19 11:53:36 -07:00
delayacct.c	Add scaled time to taskstats based process accounting	2007-10-18 14:37:28 -07:00
dma.c	whitespace fixes: DMA channel allocator	2007-10-18 14:37:24 -07:00
exec_domain.c	whitespace fixes: execution domains	2007-10-18 14:37:26 -07:00
exit.c	Make access to task's nsproxy lighter	2007-10-19 11:53:37 -07:00
extable.c
fork.c	Make access to task's nsproxy lighter	2007-10-19 11:53:37 -07:00
futex.c	sparse pointer use of zero as null	2007-10-18 14:37:31 -07:00
futex_compat.c
hrtimer.c	hrtimer: Rework hrtimer_nanosleep to make sys_compat_nanosleep easier	2007-10-18 22:54:18 +02:00
itimer.c	whitespace fixes: interval timers	2007-10-18 14:37:26 -07:00
kallsyms.c
Kconfig.hz
Kconfig.preempt	Move PREEMPT_NOTIFIERS into an always-included Kconfig	2007-10-17 08:42:55 -07:00
kexec.c	pid namespaces: define is_global_init() and is_container_init()	2007-10-19 11:53:37 -07:00
kfifo.c
kmod.c
kprobes.c
ksysfs.c	add-vmcore: cleanup the coding style according to Andrew's comments	2007-10-17 08:42:54 -07:00
kthread.c
latency.c
lockdep.c
lockdep_internals.h
lockdep_proc.c
Makefile	cgroups: implement namespace tracking subsystem	2007-10-19 11:53:37 -07:00
module.c	whitespace fixes: module loading	2007-10-18 14:37:25 -07:00
mutex-debug.c
mutex-debug.h
mutex.c
mutex.h
notifier.c	Add kernel/notifier.c	2007-10-19 11:53:34 -07:00
ns_cgroup.c	cgroups: implement namespace tracking subsystem	2007-10-19 11:53:37 -07:00
nsproxy.c	Make access to task's nsproxy lighter	2007-10-19 11:53:37 -07:00
panic.c	whitespace fixes: panic handling	2007-10-18 14:37:25 -07:00
params.c	param_sysfs_builtin memchr argument fix	2007-10-18 14:37:21 -07:00
pid.c	pid namespaces: define is_global_init() and is_container_init()	2007-10-19 11:53:37 -07:00
posix-cpu-timers.c
posix-timers.c	hrtimer: Rework hrtimer_nanosleep to make sys_compat_nanosleep easier	2007-10-18 22:54:18 +02:00
printk.c	serial: turn serial console suspend a boot rather than compile time option	2007-10-18 14:37:19 -07:00
profile.c	make kernel/profile.c:time_hook static	2007-10-17 08:42:55 -07:00
ptrace.c
rcupdate.c	Clean up duplicate includes in kernel/	2007-10-17 08:42:48 -07:00
rcutorture.c	Make rcutorture RNG use temporal entropy	2007-10-17 08:42:53 -07:00
relay.c	whitespace fixes: relayfs	2007-10-18 14:37:24 -07:00
resource.c
rtmutex-debug.c	kernel/rtmutex-debug.c: cleanups	2007-10-17 08:42:50 -07:00
rtmutex-debug.h
rtmutex-tester.c
rtmutex.c
rtmutex.h
rtmutex_common.h
rwsem.c
sched.c	Task Control Groups: example CPU accounting subsystem	2007-10-19 11:53:36 -07:00
sched_debug.c	sched: reduce schedstat variable overhead a bit	2007-10-18 21:32:56 +02:00
sched_fair.c
sched_idletask.c
sched_rt.c
sched_stats.h	sched: reduce schedstat variable overhead a bit	2007-10-18 21:32:56 +02:00
seccomp.c
signal.c	pid namespaces: define is_global_init() and is_container_init()	2007-10-19 11:53:37 -07:00
softirq.c
softlockup.c
spinlock.c
srcu.c
stacktrace.c
stop_machine.c
sys.c	pid namespaces: round up the API	2007-10-19 11:53:37 -07:00
sys_ni.c	kernel/sys_ni.c: add dummy sys_ni_syscall() prototype	2007-10-17 08:42:55 -07:00
sysctl.c	pid namespaces: define is_global_init() and is_container_init()	2007-10-19 11:53:37 -07:00
sysctl_check.c	V3 file capabilities: alter behavior of cap_setpcap	2007-10-18 14:37:24 -07:00
taskstats.c	Add cgroupstats	2007-10-19 11:53:36 -07:00
time.c	whitespace fixes: time syscalls	2007-10-18 14:37:24 -07:00
timer.c	Add scaled time to taskstats based process accounting	2007-10-18 14:37:28 -07:00
tsacct.c	Add scaled time to taskstats based process accounting	2007-10-18 14:37:28 -07:00
uid16.c
user.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched	2007-10-17 09:11:18 -07:00
user_namespace.c
utsname.c
utsname_sysctl.c
wait.c
workqueue.c