Eric W. Biederman 728dba3a39 namespaces: Use task_lock and not rcu to protect nsproxy ... The synchronous syncrhonize_rcu in switch_task_namespaces makes setns a sufficiently expensive system call that people have complained. Upon inspect nsproxy no longer needs rcu protection for remote reads. remote reads are rare. So optimize for same process reads and write by switching using rask_lock instead. This yields a simpler to understand lock, and a faster setns system call. In particular this fixes a performance regression observed by Rafael David Tinoco <rafael.tinoco@canonical.com>. This is effectively a revert of Pavel Emelyanov's commit cf7b708c8d Make access to task's nsproxy lighter from 2007. The race this originialy fixed no longer exists as do_notify_parent uses task_active_pid_ns(parent) instead of parent->nsproxy. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>		2014-07-29 18:08:50 -07:00
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compat_mq.c	ipc, kernel: use Linux headers	2014-06-06 16:08:14 -07:00
compat.c	ipc, kernel: use Linux headers	2014-06-06 16:08:14 -07:00
ipc_sysctl.c	ipc: convert use of typedef ctl_table to struct ctl_table	2014-06-06 16:08:16 -07:00
ipcns_notifier.c	ipc: do not use a negative value to re-enable msgmni automatic recomputing	2008-07-25 10:53:42 -07:00
Makefile	Add generic sys_ipc wrapper	2010-03-12 15:52:32 -08:00
mq_sysctl.c	ipc: convert use of typedef ctl_table to struct ctl_table	2014-06-06 16:08:16 -07:00
mqueue.c	ipc: use device_initcall	2014-04-07 16:36:11 -07:00
msg.c	ipc,msg: document volatile r_msg	2014-06-06 16:08:15 -07:00
msgutil.c	ipc, msg: fix message length check for negative values	2013-11-13 12:09:36 +09:00
namespace.c	namespaces: Use task_lock and not rcu to protect nsproxy	2014-07-29 18:08:50 -07:00
sem.c	ipc/sem.c: add a printk_once for semctl(GETNCNT/GETZCNT)	2014-06-06 16:08:15 -07:00
shm.c	ipc/shm.c: check for integer overflow during shmget.	2014-06-06 16:08:14 -07:00
syscall.c	get rid of union semop in sys_semctl(2) arguments	2013-03-05 15:14:16 -05:00
util.c	ipc, kernel: clear whitespace	2014-06-06 16:08:14 -07:00
util.h	ipc, kernel: clear whitespace	2014-06-06 16:08:14 -07:00