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* kernel: add CLONE_IO to specifically request sharing of IO contextsJens Axboe2008-01-281-4/+10
| | | | | | | syslets (or other threads/processes that want io context sharing) can set this to enforce sharing of io context. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* io context sharing: preliminary supportJens Axboe2008-01-281-1/+0
| | | | | | | Detach task state from ioc, instead keep track of how many processes are accessing the ioc. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* ioprio: move io priority from task_struct to io_contextJens Axboe2008-01-281-5/+27
| | | | | | | This is where it belongs and then it doesn't take up space for a process that doesn't do IO. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* sched: latencytop supportArjan van de Ven2008-01-251-0/+1
| | | | | | | | LatencyTOP kernel infrastructure; it measures latencies in the scheduler and tracks it system wide and per process. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: rt group schedulingPeter Zijlstra2008-01-251-1/+1
| | | | | | | | | | | | | | | | | Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* Preempt-RCU: implementationPaul E. McKenney2008-01-251-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch implements a new version of RCU which allows its read-side critical sections to be preempted. It uses a set of counter pairs to keep track of the read-side critical sections and flips them when all tasks exit read-side critical section. The details of this implementation can be found in this paper - http://www.rdrop.com/users/paulmck/RCU/OLSrtRCU.2006.08.11a.pdf and the article- http://lwn.net/Articles/253651/ This patch was developed as a part of the -rt kernel development and meant to provide better latencies when read-side critical sections of RCU don't disable preemption. As a consequence of keeping track of RCU readers, the readers have a slight overhead (optimizations in the paper). This implementation co-exists with the "classic" RCU implementations and can be switched to at compiler. Also includes RCU tracing summarized in debugfs. [ akpm@linux-foundation.org: build fixes on non-preempt architectures ] Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Dipankar Sarma <dipankar@in.ibm.com> Signed-off-by: Paul E. McKenney <paulmck@us.ibm.com> Reviewed-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: add RT-balance cpu-weightGregory Haskins2008-01-251-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some RT tasks (particularly kthreads) are bound to one specific CPU. It is fairly common for two or more bound tasks to get queued up at the same time. Consider, for instance, softirq_timer and softirq_sched. A timer goes off in an ISR which schedules softirq_thread to run at RT50. Then the timer handler determines that it's time to smp-rebalance the system so it schedules softirq_sched to run. So we are in a situation where we have two RT50 tasks queued, and the system will go into rt-overload condition to request other CPUs for help. This causes two problems in the current code: 1) If a high-priority bound task and a low-priority unbounded task queue up behind the running task, we will fail to ever relocate the unbounded task because we terminate the search on the first unmovable task. 2) We spend precious futile cycles in the fast-path trying to pull overloaded tasks over. It is therefore optimial to strive to avoid the overhead all together if we can cheaply detect the condition before overload even occurs. This patch tries to achieve this optimization by utilizing the hamming weight of the task->cpus_allowed mask. A weight of 1 indicates that the task cannot be migrated. We will then utilize this information to skip non-migratable tasks and to eliminate uncessary rebalance attempts. We introduce a per-rq variable to count the number of migratable tasks that are currently running. We only go into overload if we have more than one rt task, AND at least one of them is migratable. In addition, we introduce a per-task variable to cache the cpus_allowed weight, since the hamming calculation is probably relatively expensive. We only update the cached value when the mask is updated which should be relatively infrequent, especially compared to scheduling frequency in the fast path. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* softlockup: automatically detect hung TASK_UNINTERRUPTIBLE tasksIngo Molnar2008-01-251-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | this patch extends the soft-lockup detector to automatically detect hung TASK_UNINTERRUPTIBLE tasks. Such hung tasks are printed the following way: ------------------> INFO: task prctl:3042 blocked for more than 120 seconds. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message prctl D fd5e3793 0 3042 2997 f6050f38 00000046 00000001 fd5e3793 00000009 c06d8264 c06dae80 00000286 f6050f40 f6050f00 f7d34d90 f7d34fc8 c1e1be80 00000001 f6050000 00000000 f7e92d00 00000286 f6050f18 c0489d1a f6050f40 00006605 00000000 c0133a5b Call Trace: [<c04883a5>] schedule_timeout+0x6d/0x8b [<c04883d8>] schedule_timeout_uninterruptible+0x15/0x17 [<c0133a76>] msleep+0x10/0x16 [<c0138974>] sys_prctl+0x30/0x1e2 [<c0104c52>] sysenter_past_esp+0x5f/0xa5 ======================= 2 locks held by prctl/3042: #0: (&sb->s_type->i_mutex_key#5){--..}, at: [<c0197d11>] do_fsync+0x38/0x7a #1: (jbd_handle){--..}, at: [<c01ca3d2>] journal_start+0xc7/0xe9 <------------------ the current default timeout is 120 seconds. Such messages are printed up to 10 times per bootup. If the system has crashed already then the messages are not printed. if lockdep is enabled then all held locks are printed as well. this feature is a natural extension to the softlockup-detector (kernel locked up without scheduling) and to the NMI watchdog (kernel locked up with IRQs disabled). [ Gautham R Shenoy <ego@in.ibm.com>: CPU hotplug fixes. ] [ Andrew Morton <akpm@linux-foundation.org>: build warning fix. ] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
* fix clone(CLONE_NEWPID)Eric W. Biederman2007-12-051-15/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently we are complicating the code in copy_process, the clone ABI, and if we fix the bugs sys_setsid itself, with an unnecessary open coded version of sys_setsid. So just simplify everything and don't special case the session and pgrp of the initial process in a pid namespace. Having this special case actually presents to user space the classic linux startup conditions with session == pgrp == 0 for /sbin/init. We already handle sending signals to processes in a child pid namespace. We need to handle sending signals to processes in a parent pid namespace for cases like SIGCHILD and SIGIO. This makes nothing extra visible inside a pid namespace. So this extra special case appears to have no redeeming merits. Further removing this special case increases the flexibility of how we can use pid namespaces, by not requiring the initial process in a pid namespace to be a daemon. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sched: fix copy_namespace() <-> sched_fork() dependency in do_forkSrivatsa Vaddagiri2007-11-091-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Sukadev Bhattiprolu reported a kernel crash with control groups. There are couple of problems discovered by Suka's test: - The test requires the cgroup filesystem to be mounted with atleast the cpu and ns options (i.e both namespace and cpu controllers are active in the same hierarchy). # mkdir /dev/cpuctl # mount -t cgroup -ocpu,ns none cpuctl (or simply) # mount -t cgroup none cpuctl -> Will activate all controllers in same hierarchy. - The test invokes clone() with CLONE_NEWNS set. This causes a a new child to be created, also a new group (do_fork->copy_namespaces->ns_cgroup_clone-> cgroup_clone) and the child is attached to the new group (cgroup_clone-> attach_task->sched_move_task). At this point in time, the child's scheduler related fields are uninitialized (including its on_rq field, which it has inherited from parent). As a result sched_move_task thinks its on runqueue, when it isn't. As a solution to this problem, I moved sched_fork() call, which initializes scheduler related fields on a new task, before copy_namespaces(). I am not sure though whether moving up will cause other side-effects. Do you see any issue? - The second problem exposed by this test is that task_new_fair() assumes that parent and child will be part of the same group (which needn't be as this test shows). As a result, cfs_rq->curr can be NULL for the child. The solution is to test for curr pointer being NULL in task_new_fair(). With the patch below, I could run ns_exec() fine w/o a crash. Reported-by: Sukadev Bhattiprolu <sukadev@us.ibm.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: fix /proc/<PID>/stat stime/utime monotonicity, part 2Balbir Singh2007-10-301-0/+1
| | | | | | | | | Extend Peter's patch to fix accounting issues, by keeping stime monotonic too. Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Tested-by: Frans Pop <elendil@planet.nl>
* sched: keep utime/stime monotonicPeter Zijlstra2007-10-291-0/+1
| | | | | | | | | | | keep utime/stime monotonic. cpustats use utime/stime as a ratio against sum_exec_runtime, as a consequence it can happen - when the ratio changes faster than time accumulates - that either can be appear to go backwards. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* Uninline fork.c/exit.cAlexey Dobriyan2007-10-191-10/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Save ~650 bytes here. add/remove: 4/0 grow/shrink: 0/7 up/down: 430/-1088 (-658) function old new delta __copy_fs_struct - 202 +202 __put_fs_struct - 112 +112 __exit_fs - 58 +58 __exit_files - 58 +58 exit_files 58 2 -56 put_fs_struct 112 5 -107 exit_fs 161 2 -159 sys_unshare 774 590 -184 copy_process 4031 3840 -191 do_exit 1791 1597 -194 copy_fs_struct 202 5 -197 No difference in lmbench lat_proc tests on 2-way Opteron 246. Smaaaal degradation on UP P4 (within errors). [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Cc: Arjan van de Ven <arjan@infradead.org> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kernel/fork.c: remove unneeded variable initialization in copy_process()Mariusz Kozlowski2007-10-191-1/+1
| | | | | | | | This initialization of is not needed so just remove it. Signed-off-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Isolate the explicit usage of signal->pgrpPavel Emelyanov2007-10-191-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The pgrp field is not used widely around the kernel so it is now marked as deprecated with appropriate comment. The initialization of INIT_SIGNALS is trimmed because a) they are set to 0 automatically; b) gcc cannot properly initialize two anonymous (the second one is the one with the session) unions. In this particular case to make it compile we'd have to add some field initialized right before the .pgrp. This is the same patch as the 1ec320afdc9552c92191d5f89fcd1ebe588334ca one (from Cedric), but for the pgrp field. Some progress report: We have to deprecate the pid, tgid, session and pgrp fields on struct task_struct and struct signal_struct. The session and pgrp are already deprecated. The tgid value is close to being such - the worst known usage in in fs/locks.c and audit code. The pid field deprecation is mainly blocked by numerous printk-s around the kernel that print the tsk->pid to log. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: Serge Hallyn <serue@us.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Herbert Poetzl <herbert@13thfloor.at> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Fix tsk->exit_state usageEugene Teo2007-10-191-1/+1
| | | | | | | | | | | | tsk->exit_state can only be 0, EXIT_ZOMBIE, or EXIT_DEAD. A non-zero test is the same as tsk->exit_state & (EXIT_ZOMBIE | EXIT_DEAD), so just testing tsk->exit_state is sufficient. Signed-off-by: Eugene Teo <eugeneteo@kernel.sg> Cc: Roland McGrath <roland@redhat.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* pid namespaces: changes to show virtual ids to userPavel Emelyanov2007-10-191-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is the largest patch in the set. Make all (I hope) the places where the pid is shown to or get from user operate on the virtual pids. The idea is: - all in-kernel data structures must store either struct pid itself or the pid's global nr, obtained with pid_nr() call; - when seeking the task from kernel code with the stored id one should use find_task_by_pid() call that works with global pids; - when showing pid's numerical value to the user the virtual one should be used, but however when one shows task's pid outside this task's namespace the global one is to be used; - when getting the pid from userspace one need to consider this as the virtual one and use appropriate task/pid-searching functions. [akpm@linux-foundation.org: build fix] [akpm@linux-foundation.org: nuther build fix] [akpm@linux-foundation.org: yet nuther build fix] [akpm@linux-foundation.org: remove unneeded casts] Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: Alexey Dobriyan <adobriyan@openvz.org> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Paul Menage <menage@google.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* pid namespaces: initialize the namespace's proc_mntPavel Emelyanov2007-10-191-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | The namespace's proc_mnt must be kern_mount-ed to make this pointer always valid, independently of whether the user space mounted the proc or not. This solves raced in proc_flush_task, etc. with the proc_mnt switching from NULL to not-NULL. The initialization is done after the init's pid is created and hashed to make proc_get_sb() finr it and get for root inode. Sice the namespace holds the vfsmnt, vfsmnt holds the superblock and the superblock holds the namespace we must explicitly break this circle to destroy all the stuff. This is done after the init of the namespace dies. Running a few steps forward - when init exits it will kill all its children, so no proc_mnt will be needed after its death. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Cc: Paul Menage <menage@google.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* pid namespaces: allow cloning of new namespacePavel Emelyanov2007-10-191-15/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When clone() is invoked with CLONE_NEWPID, create a new pid namespace and then create a new struct pid for the new process. Allocate pid_t's for the new process in the new pid namespace and all ancestor pid namespaces. Make the newly cloned process the session and process group leader. Since the active pid namespace is special and expected to be the first entry in pid->upid_list, preserve the order of pid namespaces. The size of 'struct pid' is dependent on the the number of pid namespaces the process exists in, so we use multiple pid-caches'. Only one pid cache is created during system startup and this used by processes that exist only in init_pid_ns. When a process clones its pid namespace, we create additional pid caches as necessary and use the pid cache to allocate 'struct pids' for that depth. Note, that with this patch the newly created namespace won't work, since the rest of the kernel still uses global pids, but this is to be fixed soon. Init pid namespace still works. [oleg@tv-sign.ru: merge fix] Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com> Cc: Paul Menage <menage@google.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* pid namespaces: move alloc_pid() lower in copy_process()Pavel Emelyanov2007-10-191-15/+16
| | | | | | | | | | | | | | | | When we create new namespace we will need to allocate the struct pid, that will have one extra struct upid in array, comparing to the parent. Thus we need to know the new namespace (if any) in alloc_pid() to init this struct upid properly, so move the alloc_pid() call lower in copy_process(). Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Cc: Paul Menage <menage@google.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* pid namespaces: make alloc_pid(), free_pid() and put_pid() work with struct upidPavel Emelyanov2007-10-191-1/+1
| | | | | | | | | | | | | | | | | | | | | Each struct upid element of struct pid has to be initialized properly, i.e. its nr mst be allocated from appropriate pidmap and ns set to appropriate namespace. When allocating a new pid, we need to know the namespace this pid will live in, so the additional argument is added to alloc_pid(). On the other hand, the rest of the kernel still uses the pid->nr and pid->pid_chain fields, so these ones are still initialized, but this will be removed soon. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Cc: Paul Menage <menage@google.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Make access to task's nsproxy lighterPavel Emelyanov2007-10-191-6/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* pid namespaces: move alloc_pid() to copy_process()Sukadev Bhattiprolu2007-10-191-6/+13
| | | | | | | | | | | | | | | | | Move alloc_pid() into copy_process(). This will keep all pid and pid namespace code together and simplify error handling when we support multiple pid namespaces. Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com> Cc: Pavel Emelianov <xemul@openvz.org> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: Dave Hansen <haveblue@us.ibm.com> Cc: Serge Hallyn <serue@us.ibm.com> Cc: Herbert Poetzel <herbert@13thfloor.at> Cc: Kirill Korotaev <dev@sw.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* pid namespaces: round up the APIPavel Emelianov2007-10-191-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | The set of functions process_session, task_session, process_group and task_pgrp is confusing, as the names can be mixed with each other when looking at the code for a long time. The proposals are to * equip the functions that return the integer with _nr suffix to represent that fact, * and to make all functions work with task (not process) by making the common prefix of the same name. For monotony the routines signal_session() and set_signal_session() are replaced with task_session_nr() and set_task_session(), especially since they are only used with the explicit task->signal dereference. Signed-off-by: Pavel Emelianov <xemul@openvz.org> Acked-by: Serge E. Hallyn <serue@us.ibm.com> Cc: Kirill Korotaev <dev@openvz.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Task Control Groups: make cpusets a client of cgroupsPaul Menage2007-10-191-3/+0
| | | | | | | | | | | | | | | | | | | | | | Remove the filesystem support logic from the cpusets system and makes cpusets a cgroup subsystem The "cpuset" filesystem becomes a dummy filesystem; attempts to mount it get passed through to the cgroup filesystem with the appropriate options to emulate the old cpuset filesystem behaviour. Signed-off-by: Paul Menage <menage@google.com> Cc: Serge E. Hallyn <serue@us.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Dave Hansen <haveblue@us.ibm.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Jackson <pj@sgi.com> Cc: Kirill Korotaev <dev@openvz.org> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com> Cc: 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>
* Task Control Groups: shared cgroup subsystem group arraysPaul Menage2007-10-191-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Replace the struct css_set embedded in task_struct with a pointer; all tasks that have the same set of memberships across all hierarchies will share a css_set object, and will be linked via their css_sets field to the "tasks" list_head in the css_set. Assuming that many tasks share the same cgroup assignments, this reduces overall space usage and keeps the size of the task_struct down (three pointers added to task_struct compared to a non-cgroups kernel, no matter how many subsystems are registered). [akpm@linux-foundation.org: fix a printk] [akpm@linux-foundation.org: build fix] Signed-off-by: Paul Menage <menage@google.com> Cc: Serge E. Hallyn <serue@us.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Dave Hansen <haveblue@us.ibm.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Jackson <pj@sgi.com> Cc: Kirill Korotaev <dev@openvz.org> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: Serge E. Hallyn <serue@us.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Dave Hansen <haveblue@us.ibm.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Jackson <pj@sgi.com> Cc: Kirill Korotaev <dev@openvz.org> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Task Control Groups: add fork()/exit() hooksPaul Menage2007-10-191-2/+12
| | | | | | | | | | | | | | | | | | | This adds the necessary hooks to the fork() and exit() paths to ensure that new children inherit their parent's cgroup assignments, and that exiting processes release reference counts on their cgroups. Signed-off-by: Paul Menage <menage@google.com> Cc: Serge E. Hallyn <serue@us.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Dave Hansen <haveblue@us.ibm.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Jackson <pj@sgi.com> Cc: Kirill Korotaev <dev@openvz.org> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com> Cc: 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>
* Add scaled time to taskstats based process accountingMichael Neuling2007-10-181-0/+2
| | | | | | | | | | | | | | | | This adds items to the taststats struct to account for user and system time based on scaling the CPU frequency and instruction issue rates. Adds account_(user|system)_time_scaled callbacks which architectures can use to account for time using this mechanism. Signed-off-by: Michael Neuling <mikey@neuling.org> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Jay Lan <jlan@engr.sgi.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* whitespace fixes: forkDaniel Walker2007-10-181-10/+10
| | | | | | Signed-off-by: Daniel Walker <dwalker@mvista.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Remove struct task_struct::io_waitAlexey Dobriyan2007-10-181-1/+0
| | | | | | | | | | | | Hell knows what happened in commit 63b05203af57e7de4f3bb63b8b81d43bc196d32b during 2.6.9 development. Commit introduced io_wait field which remained write-only than and still remains write-only. Also garbage collect macros which "use" io_wait. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* freezer: prevent new tasks from inheriting TIF_FREEZE setRafael J. Wysocki2007-10-181-0/+1
| | | | | | | | | | | | Tasks should go to the refrigerator only if explicitly requested to do that by the freezer and not as a result of inheriting the TIF_FREEZE flag set from the parent. Make it happen. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Pavel Machek <pavel@ucw.cz> Acked-by: Nigel Cunningham <nigel@nigel.suspend2.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ifdef struct task_struct::securityAlexey Dobriyan2007-10-171-0/+2
| | | | | | | | | | | | For those who don't care about CONFIG_SECURITY. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Casey Schaufler <casey@schaufler-ca.com> Cc: James Morris <jmorris@namei.org> Cc: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Shrink task_struct if CONFIG_FUTEX=nAlexey Dobriyan2007-10-171-1/+2
| | | | | | | | | | robust_list, compat_robust_list, pi_state_list, pi_state_cache are really used if futexes are on. Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Slab API: remove useless ctor parameter and reorder parametersChristoph Lameter2007-10-171-2/+1
| | | | | | | | | | | | | | | | | | | | | Slab constructors currently have a flags parameter that is never used. And the order of the arguments is opposite to other slab functions. The object pointer is placed before the kmem_cache pointer. Convert ctor(void *object, struct kmem_cache *s, unsigned long flags) to ctor(struct kmem_cache *s, void *object) throughout the kernel [akpm@linux-foundation.org: coupla fixes] Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: dirty balancing for tasksPeter Zijlstra2007-10-171-0/+10
| | | | | | | | | | | | | | | | | | | | Based on ideas of Andrew: http://marc.info/?l=linux-kernel&m=102912915020543&w=2 Scale the bdi dirty limit inversly with the tasks dirty rate. This makes heavy writers have a lower dirty limit than the occasional writer. Andrea proposed something similar: http://lwn.net/Articles/152277/ The main disadvantage to his patch is that he uses an unrelated quantity to measure time, which leaves him with a workload dependant tunable. Other than that the two approaches appear quite similar. [akpm@linux-foundation.org: fix warning] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sched: guest CPU accounting: add guest-CPU /proc/<pid>/stat fieldsLaurent Vivier2007-10-151-0/+3
| | | | | | | | | | | | like for cpustat, introduce the "gtime" (guest time of the task) and "cgtime" (guest time of the task children) fields for the tasks. Modify signal_struct and task_struct. Modify /proc/<pid>/stat to display these new fields. Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net> Acked-by: Avi Kivity <avi@qumranet.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* [NET]: Add network namespace clone & unshare support.Eric W. Biederman2007-10-111-1/+2
| | | | | | | | | | | | | | | | | This patch allows you to create a new network namespace using sys_clone, or sys_unshare. As the network namespace is still experimental and under development clone and unshare support is only made available when CONFIG_NET_NS is selected at compile time. As this patch introduces network namespace support into code paths that exist when the CONFIG_NET is not selected there are a few additions made to net_namespace.h to allow a few more functions to be used when the networking stack is not compiled in. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* signalfd simplificationDavide Libenzi2007-09-201-1/+1
| | | | | | | | | | | | | | | | | | | | This simplifies signalfd code, by avoiding it to remain attached to the sighand during its lifetime. In this way, the signalfd remain attached to the sighand only during poll(2) (and select and epoll) and read(2). This also allows to remove all the custom "tsk == current" checks in kernel/signal.c, since dequeue_signal() will only be called by "current". I think this is also what Ben was suggesting time ago. The external effect of this, is that a thread can extract only its own private signals and the group ones. I think this is an acceptable behaviour, in that those are the signals the thread would be able to fetch w/out signalfd. Signed-off-by: Davide Libenzi <davidel@xmailserver.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: Remove slab destructors from kmem_cache_create().Paul Mundt2007-07-201-9/+9
| | | | | | | | | | | | | | Slab destructors were no longer supported after Christoph's c59def9f222d44bb7e2f0a559f2906191a0862d7 change. They've been BUGs for both slab and slub, and slob never supported them either. This rips out support for the dtor pointer from kmem_cache_create() completely and fixes up every single callsite in the kernel (there were about 224, not including the slab allocator definitions themselves, or the documentation references). Signed-off-by: Paul Mundt <lethal@linux-sh.org>
* lguest: the host codeRusty Russell2007-07-191-1/+0
| | | | | | | | | | | | | | | | This is the code for the "lg.ko" module, which allows lguest guests to be launched. [akpm@linux-foundation.org: update for futex-new-private-futexes] [akpm@linux-foundation.org: build fix] [jmorris@namei.org: lguest: use hrtimers] [akpm@linux-foundation.org: x86_64 build fix] Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Andi Kleen <ak@suse.de> Cc: Eric Dumazet <dada1@cosmosbay.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lguest: export symbols for lguest as a moduleRusty Russell2007-07-191-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | lguest does some fairly lowlevel things to support a host, which normal modules don't need: math_state_restore: When the guest triggers a Device Not Available fault, we need to be able to restore the FPU __put_task_struct: We need to hold a reference to another task for inter-guest I/O, and put_task_struct() is an inline function which calls __put_task_struct. access_process_vm: We need to access another task for inter-guest I/O. map_vm_area & __get_vm_area: We need to map the switcher shim (ie. monitor) at 0xFFC01000. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* coredump masking: add an interface for core dump filterKawai, Hidehiro2007-07-191-0/+2
| | | | | | | | | | | | | | | | | | | This patch adds an interface to set/reset flags which determines each memory segment should be dumped or not when a core file is generated. /proc/<pid>/coredump_filter file is provided to access the flags. You can change the flag status for a particular process by writing to or reading from the file. The flag status is inherited to the child process when it is created. Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: David Howells <dhowells@redhat.com> Cc: Hugh Dickins <hugh@veritas.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Freezer: make kernel threads nonfreezable by defaultRafael J. Wysocki2007-07-171-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, the freezer treats all tasks as freezable, except for the kernel threads that explicitly set the PF_NOFREEZE flag for themselves. This approach is problematic, since it requires every kernel thread to either set PF_NOFREEZE explicitly, or call try_to_freeze(), even if it doesn't care for the freezing of tasks at all. It seems better to only require the kernel threads that want to or need to be frozen to use some freezer-related code and to remove any freezer-related code from the other (nonfreezable) kernel threads, which is done in this patch. The patch causes all kernel threads to be nonfreezable by default (ie. to have PF_NOFREEZE set by default) and introduces the set_freezable() function that should be called by the freezable kernel threads in order to unset PF_NOFREEZE. It also makes all of the currently freezable kernel threads call set_freezable(), so it shouldn't cause any (intentional) change of behaviour to appear. Additionally, it updates documentation to describe the freezing of tasks more accurately. [akpm@linux-foundation.org: build fixes] Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Nigel Cunningham <nigel@nigel.suspend2.net> Cc: Pavel Machek <pavel@ucw.cz> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* user namespace: add unshareSerge E. Hallyn2007-07-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch enables the unshare of user namespaces. It adds a new clone flag CLONE_NEWUSER and implements copy_user_ns() which resets the current user_struct and adds a new root user (uid == 0) For now, unsharing the user namespace allows a process to reset its user_struct accounting and uid 0 in the new user namespace should be contained using appropriate means, for instance selinux The plan, when the full support is complete (all uid checks covered), is to keep the original user's rights in the original namespace, and let a process become uid 0 in the new namespace, with full capabilities to the new namespace. Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> Signed-off-by: Cedric Le Goater <clg@fr.ibm.com> Acked-by: Pavel Emelianov <xemul@openvz.org> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Kirill Korotaev <dev@sw.ru> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Chris Wright <chrisw@sous-sol.org> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: James Morris <jmorris@namei.org> Cc: Andrew Morgan <agm@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* user namespace: add the frameworkCedric Le Goater2007-07-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Basically, it will allow a process to unshare its user_struct table, resetting at the same time its own user_struct and all the associated accounting. A new root user (uid == 0) is added to the user namespace upon creation. Such root users have full privileges and it seems that theses privileges should be controlled through some means (process capabilities ?) The unshare is not included in this patch. Changes since [try #4]: - Updated get_user_ns and put_user_ns to accept NULL, and get_user_ns to return the namespace. Changes since [try #3]: - moved struct user_namespace to files user_namespace.{c,h} Changes since [try #2]: - removed struct user_namespace* argument from find_user() Changes since [try #1]: - removed struct user_namespace* argument from find_user() - added a root_user per user namespace Signed-off-by: Cedric Le Goater <clg@fr.ibm.com> Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> Acked-by: Pavel Emelianov <xemul@openvz.org> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Kirill Korotaev <dev@sw.ru> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Chris Wright <chrisw@sous-sol.org> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: James Morris <jmorris@namei.org> Cc: Andrew Morgan <agm@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Audit: add TTY input auditingMiloslav Trmac2007-07-161-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add TTY input auditing, used to audit system administrator's actions. This is required by various security standards such as DCID 6/3 and PCI to provide non-repudiation of administrator's actions and to allow a review of past actions if the administrator seems to overstep their duties or if the system becomes misconfigured for unknown reasons. These requirements do not make it necessary to audit TTY output as well. Compared to an user-space keylogger, this approach records TTY input using the audit subsystem, correlated with other audit events, and it is completely transparent to the user-space application (e.g. the console ioctls still work). TTY input auditing works on a higher level than auditing all system calls within the session, which would produce an overwhelming amount of mostly useless audit events. Add an "audit_tty" attribute, inherited across fork (). Data read from TTYs by process with the attribute is sent to the audit subsystem by the kernel. The audit netlink interface is extended to allow modifying the audit_tty attribute, and to allow sending explanatory audit events from user-space (for example, a shell might send an event containing the final command, after the interactive command-line editing and history expansion is performed, which might be difficult to decipher from the TTY input alone). Because the "audit_tty" attribute is inherited across fork (), it would be set e.g. for sshd restarted within an audited session. To prevent this, the audit_tty attribute is cleared when a process with no open TTY file descriptors (e.g. after daemon startup) opens a TTY. See https://www.redhat.com/archives/linux-audit/2007-June/msg00000.html for a more detailed rationale document for an older version of this patch. [akpm@linux-foundation.org: build fix] Signed-off-by: Miloslav Trmac <mitr@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Paul Fulghum <paulkf@microgate.com> Cc: Casey Schaufler <casey@schaufler-ca.com> Cc: Steve Grubb <sgrubb@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Use boot based time for process start time and boot time in /procTomas Janousek2007-07-161-0/+2
| | | | | | | | | | | | | | | Commit 411187fb05cd11676b0979d9fbf3291db69dbce2 caused boot time to move and process start times to become invalid after suspend. Using boot based time for those restores the old behaviour and fixes the issue. [akpm@linux-foundation.org: little cleanup] Signed-off-by: Tomas Janousek <tjanouse@redhat.com> Cc: Tomas Smetana <tsmetana@redhat.com> Acked-by: John Stultz <johnstul@us.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sched: update delay-accounting to use CFS's precise statsBalbir Singh2007-07-091-2/+2
| | | | | | update delay-accounting to use CFS's precise stats. Signed-off-by: Ingo Molnar <mingo@elte.hu>
* freezer: fix vfork problemRafael J. Wysocki2007-05-241-0/+3
| | | | | | | | | | | | | | | | | | | Currently try_to_freeze_tasks() has to wait until all of the vforked processes exit and for this reason every user can make it fail. To fix this problem we can introduce the additional process flag PF_FREEZER_SKIP to be used by tasks that do not want to be counted as freezable by the freezer and want to have TIF_FREEZE set nevertheless. Then, this flag can be set by tasks using sys_vfork() before they call wait_for_completion(&vfork) and cleared after they have woken up. After clearing it, the tasks should call try_to_freeze() as soon as possible. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Gautham R Shenoy <ego@in.ibm.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Remove SLAB_CTOR_CONSTRUCTORChristoph Lameter2007-05-171-4/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | SLAB_CTOR_CONSTRUCTOR is always specified. No point in checking it. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: David Howells <dhowells@redhat.com> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Steven French <sfrench@us.ibm.com> Cc: Michael Halcrow <mhalcrow@us.ibm.com> Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Roman Zippel <zippel@linux-m68k.org> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Dave Kleikamp <shaggy@austin.ibm.com> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: Anton Altaparmakov <aia21@cantab.net> Cc: Mark Fasheh <mark.fasheh@oracle.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Jan Kara <jack@ucw.cz> Cc: David Chinner <dgc@sgi.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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