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* cgroups: remove node_ prefix_from ns subsystemCedric Le Goater2008-05-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is a slight change in the namespace cgroup subsystem api. The change is that previously when cgroup_clone() was called (currently only from the unshare path in ns_proxy cgroup, you'd get a new group named "node_$pid" whereas now you'll get a group named after just your pid.) The only users who would notice it are those who are using the ns_proxy cgroup subsystem to auto-create cgroups when namespaces are unshared - something of an experimental feature, which I think really needs more complete container/namespace support in order to be useful. I suspect the only users are Cedric and Serge, or maybe a few others on containers@lists.linux-foundation.org. And in fact it would only be noticed by the users who make the assumption about how the name is generated, rather than getting it from the /proc/<pid>/cgroups file for the process in question. Whether the change is actually needed or not I'm fairly agnostic on, but I guess it is more elegant to just use the pid as the new group name rather than adding a fairly arbitrary "node_" prefix on the front. [menage@google.com: provided changelog] Signed-off-by: Cedric Le Goater <clg@fr.ibm.com> Cc: "Paul Menage" <menage@google.com> Cc: "Serge E. Hallyn" <serue@us.ibm.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: bdi: add separate writeback accounting capabilityMiklos Szeredi2008-04-301-1/+1
| | | | | | | | | | | | | | | | | Add a new BDI capability flag: BDI_CAP_NO_ACCT_WB. If this flag is set, then don't update the per-bdi writeback stats from test_set_page_writeback() and test_clear_page_writeback(). Misc cleanups: - convert bdi_cap_writeback_dirty() and friends to static inline functions - create a flag that includes all three dirty/writeback related flags, since almst all users will want to have them toghether Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Cc: 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>
* cgroups: add an owner to the mm_structBalbir Singh2008-04-291-0/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove the mem_cgroup member from mm_struct and instead adds an owner. This approach was suggested by Paul Menage. The advantage of this approach is that, once the mm->owner is known, using the subsystem id, the cgroup can be determined. It also allows several control groups that are virtually grouped by mm_struct, to exist independent of the memory controller i.e., without adding mem_cgroup's for each controller, to mm_struct. A new config option CONFIG_MM_OWNER is added and the memory resource controller selects this config option. This patch also adds cgroup callbacks to notify subsystems when mm->owner changes. The mm_cgroup_changed callback is called with the task_lock() of the new task held and is called just prior to changing the mm->owner. I am indebted to Paul Menage for the several reviews of this patchset and helping me make it lighter and simpler. This patch was tested on a powerpc box, it was compiled with both the MM_OWNER config turned on and off. After the thread group leader exits, it's moved to init_css_state by cgroup_exit(), thus all future charges from runnings threads would be redirected to the init_css_set's subsystem. Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Pavel Emelianov <xemul@openvz.org> Cc: Hugh Dickins <hugh@veritas.com> Cc: Sudhir Kumar <skumar@linux.vnet.ibm.com> Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp> Cc: Hirokazu Takahashi <taka@valinux.co.jp> Cc: David Rientjes <rientjes@google.com>, Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Reviewed-by: Paul Menage <menage@google.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>
* cgroups: introduce cft->read_seq()Serge E. Hallyn2008-04-291-6/+9
| | | | | | | | | | | | | | Introduce a read_seq() helper in cftype, which uses seq_file to print out lists. Use it in the devices cgroup. Also split devices.allow into two files, so now devices.deny and devices.allow are the ones to use to manipulate the whitelist, while devices.list outputs the cgroup's current whitelist. Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> Acked-by: Paul Menage <menage@google.com> Cc: Balbir Singh <balbir@in.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>
* cgroups: remove the css_set linked-listLi Zefan2008-04-291-20/+20
| | | | | | | | | | | | | Now we can run through the hash table instead of running through the linked-list. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Reviewed-by: Paul Menage <menage@google.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> 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>
* cgroups: simplify init_subsys()Li Zefan2008-04-291-26/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | We are at system boot and there is only 1 cgroup group (i,e, init_css_set), so we don't need to run through the css_set linked list. Neither do we need to run through the task list, since no processes have been created yet. Also referring to a comment in cgroup.h: struct css_set { ... /* * Set of subsystem states, one for each subsystem. This array * is immutable after creation apart from the init_css_set * during subsystem registration (at boot time). */ struct cgroup_subsys_state *subsys[CGROUP_SUBSYS_COUNT]; } Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Reviewed-by: Paul Menage <menage@google.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> 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>
* cgroups: use a hash table for css_set findingLi Zefan2008-04-291-12/+47
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we attach a process to a different cgroup, the css_set linked-list will be run through to find a suitable existing css_set to use. This patch implements a hash table for better performance. The following benchmarks have been tested: For N in 1, 5, 10, 50, 100, 500, 1000, create N cgroups with one sleeping task in each, and then move an additional task through each cgroup in turn. Here is a test result: N Loop orig - Time(s) hash - Time(s) ---------------------------------------------- 1 10000 1.201231728 1.196311177 5 2000 1.065743872 1.040566424 10 1000 0.991054735 0.986876440 50 200 0.976554203 0.969608733 100 100 0.998504680 0.969218270 500 20 1.157347764 0.962602963 1000 10 1.619521852 1.085140172 Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Reviewed-by: Paul Menage <menage@google.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> 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>
* cgroups: add the trigger callback to struct cftypePavel Emelyanov2008-04-291-0/+4
| | | | | | | | | | | | | | Trigger callback can be used to receive a kick-up from the user space. The string written is ignored. The cftype->private is used for multiplexing events. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Acked-by: Paul Menage <menage@google.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cgroup: switch to proc_create()Li Zefan2008-04-291-4/+1
| | | | | | | | | | There is a race between create_proc_entry() and the assignment of file ops. proc_create() is invented to fix it. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cgroup: annotate cgroup_init_subsys with __initLi Zefan2008-04-291-1/+1
| | | | | | | | | | It is called by cgroup_init() and cgroup_init_early() only, which are annotated with __init. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* CGroups _s64 files: add cgroups read_s64/write_s64 file methodsPaul Menage2008-04-291-10/+28
| | | | | | | | | | | | | | | | These patches add cgroups read_s64 and write_s64 control file methods (the signed equivalent of read_u64/write_u64) and use them to implement the cpu.rt_runtime_us control file in the CFS cgroup subsystem. This patch: These are the signed equivalents of the read_u64/write_u64 methods Signed-off-by: Paul Menage <menage@google.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* CGroup API files: move "releasable" to cgroup_debug subsystemPaul Menage2008-04-291-23/+0
| | | | | | | | | | | | | | | | | | | The "releasable" control file provided by the cgroup framework exports the state of a per-cgroup flag that's related to the notify-on-release feature. This isn't really generally useful, unless you're trying to debug this particular feature of cgroups. This patch moves the "releasable" file to the cgroup_debug subsystem. Signed-off-by: Paul Menage <menage@google.com> Cc: "Li Zefan" <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Jackson <pj@sgi.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: "YAMAMOTO Takashi" <yamamoto@valinux.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* CGroup API files: add cgroup map data typePaul Menage2008-04-291-1/+52
| | | | | | | | | | | | | | | | | | Adds a new type of supported control file representation, a map from strings to u64 values. Each map entry is printed as a line in a similar format to /proc/vmstat, i.e. "$key $value\n" Signed-off-by: Paul Menage <menage@google.com> Cc: "Li Zefan" <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Jackson <pj@sgi.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: "YAMAMOTO Takashi" <yamamoto@valinux.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* CGroup API files: strip all trailing whitespace in cgroup_write_u64Paul Menage2008-04-291-4/+1
| | | | | | | | | | | | | | | This removes the need for people to remember to pass the -n flag to echo when writing values to cgroup control files. Signed-off-by: Paul Menage <menage@google.com> Cc: "Li Zefan" <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Jackson <pj@sgi.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: "YAMAMOTO Takashi" <yamamoto@valinux.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* CGroup API files: rename read/write_uint methods to read_write_u64Paul Menage2008-04-291-16/+16
| | | | | | | | | | | | | | | | | | Several people have justifiably complained that the "_uint" suffix is inappropriate for functions that handle u64 values, so this patch just renames all these functions and their users to have the suffic _u64. [peterz@infradead.org: build fix] Signed-off-by: Paul Menage <menage@google.com> Cc: "Li Zefan" <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Jackson <pj@sgi.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: "YAMAMOTO Takashi" <yamamoto@valinux.co.jp> 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>
* cgroup: fix sparse warning of shadow symbol in cgroup.cPaul Jackson2008-04-291-5/+5
| | | | | | | | | | | | | | | | | | Fix a code warning: symbol 'p' shadows an earlier one This is a reincarnation of Harvey Harrison's patch: cpuset: sparse warnings in cpuset.c Independently, Cliff Wickman moved the affected code, from kernel/cpuset.c to kernel/cgroup.c, in his patch: cpusets: update_cpumask revision Signed-off-by: Paul Jackson <pj@sgi.com> Cc: Harvey Harrison <harvey.harrison@gmail.com> Cc: Cliff Wickman <cpw@sgi.com> Acked-by: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* make cgroup_enable_task_cg_lists() staticAdrian Bunk2008-04-291-1/+1
| | | | | | | | | | Make the needlessly global cgroup_enable_task_cg_lists() static. Signed-off-by: Adrian Bunk <bunk@kernel.org> Acked-by: David Rientjes <rientjes@google.com> Cc: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cgroup: fix a race condition in manipulating tsk->cg_listLi Zefan2008-04-181-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When I ran a test program to fork mass processes and at the same time 'cat /cgroup/tasks', I got the following oops: ------------[ cut here ]------------ kernel BUG at lib/list_debug.c:72! invalid opcode: 0000 [#1] SMP Pid: 4178, comm: a.out Not tainted (2.6.25-rc9 #72) ... Call Trace: [<c044a5f9>] ? cgroup_exit+0x55/0x94 [<c0427acf>] ? do_exit+0x217/0x5ba [<c0427ed7>] ? do_group_exit+0.65/0x7c [<c0427efd>] ? sys_exit_group+0xf/0x11 [<c0404842>] ? syscall_call+0x7/0xb [<c05e0000>] ? init_cyrix+0x2fa/0x479 ... EIP: [<c04df671>] list_del+0x35/0x53 SS:ESP 0068:ebc7df4 ---[ end trace caffb7332252612b ]--- Fixing recursive fault but reboot is needed! After digging into the code and debugging, I finlly found out a race situation: do_exit() ->cgroup_exit() ->if (!list_empty(&tsk->cg_list)) list_del(&tsk->cg_list); cgroup_iter_start() ->cgroup_enable_task_cg_list() ->list_add(&tsk->cg_list, ..); In this case the list won't be deleted though the process has exited. We got two bug reports in the past, which seem to be the same bug as this one: http://lkml.org/lkml/2008/3/5/332 http://lkml.org/lkml/2007/10/17/224 Actually sometimes I got oops on list_del, sometimes oops on list_add. And I can change my test program a bit to trigger other oops. The patch has been tested both on x86_32 and x86_64. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Paul Menage <menage@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cgroups: include hierarchy ids in /proc/<pid>/cgroupPaul Menage2008-04-111-0/+1
| | | | | | | | | | | | | | | | | | Extend the /proc/<pid>/cgroup file to include the appropriate hierarchy ID on each line. Currently this ID isn't really needed since a hierarchy can be completely identified by the set of subsystems bound to it, but this is likely to change in the near future in order to support stateless subsystems and merging/rebinding of subsystems. Getting this change into 2.6.25 reduces the need for an API change later. Signed-off-by: Paul Menage <menage@google.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> 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>
* cgroups: add cgroup support for enabling controllers at boot timePaul Menage2008-04-041-5/+37
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The effects of cgroup_disable=foo are: - foo isn't auto-mounted if you mount all cgroups in a single hierarchy - foo isn't visible as an individually mountable subsystem As a result there will only ever be one call to foo->create(), at init time; all processes will stay in this group, and the group will never be mounted on a visible hierarchy. Any additional effects (e.g. not allocating metadata) are up to the foo subsystem. This doesn't handle early_init subsystems (their "disabled" bit isn't set be, but it could easily be extended to do so if any of the early_init systems wanted it - I think it would just involve some nastier parameter processing since it would occur before the command-line argument parser had been run. Hugh said: Ballpark figures, I'm trying to get this question out rather than processing the exact numbers: CONFIG_CGROUP_MEM_RES_CTLR adds 15% overhead to the affected paths, booting with cgroup_disable=memory cuts that back to 1% overhead (due to slightly bigger struct page). I'm no expert on distros, they may have no interest whatever in CONFIG_CGROUP_MEM_RES_CTLR=y; and the rest of us can easily build with or without it, or apply the cgroup_disable=memory patches. Unix bench's execl test result on x86_64 was == just after boot without mounting any cgroup fs.== mem_cgorup=off : Execl Throughput 43.0 3150.1 732.6 mem_cgroup=on : Execl Throughput 43.0 2932.6 682.0 == [lizf@cn.fujitsu.com: fix boot option parsing] Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hugh@veritas.com> Cc: Sudhir Kumar <skumar@linux.vnet.ibm.com> Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* NULL noise: fs/*, mm/*, kernel/*Al Viro2008-03-301-2/+2
| | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cgroup: fix default notify_on_release settingLi Zefan2008-03-051-1/+3
| | | | | | | | | | | The documentation says the default value of notify_on_release of a child cgroup is inherited from its parent, which is reasonable, but the implementation just sets the flag disabled. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cgroup: remove dead code in cgroup_get_rootdir()Li Zefan2008-02-241-1/+0
| | | | | | | Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cgroup: remove duplicate code in find_css_set()Li Zefan2008-02-241-1/+0
| | | | | | | | | The list head res->tasks gets initialized twice in find_css_set(). Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cgroup: fix subsys bitopsLi Zefan2008-02-241-2/+2
| | | | | | | | | Cgroup uses unsigned long for subsys bitops, not unsigned long long. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cgroup: fix memory leak in cgroup_get_sb()Li Zefan2008-02-241-1/+4
| | | | | | | | | opts.release_agent is not kfree()ed in all necessary places. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cgroup: fix commentsLi Zefan2008-02-241-63/+79
| | | | | | | | | | | | fix: - comments about need_forkexit_callback - comments about release agent - typo and comment style, etc. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Handle pid namespaces in cgroups codePavel Emelyanov2008-02-071-2/+2
| | | | | | | | | | | | | | | There's one place that works with task pids - its the "tasks" file in cgroups. The read/write handlers assume, that the pid values go to/come from the user space and thus it is a virtual pid, i.e. the pid as it is seen from inside a namespace. Tune the code accordingly. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* hotplug cpu: move tasks in empty cpusets to parentCliff Wickman2008-02-071-11/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | This patch corrects a situation that occurs when one disables all the cpus in a cpuset. Currently, the disabled (cpu-less) cpuset inherits the cpus of its parent, which is incorrect because it may then overlap its cpu-exclusive sibling. Tasks of an empty cpuset should be moved to the cpuset which is the parent of their current cpuset. Or if the parent cpuset has no cpus, to its parent, etc. And the empty cpuset should be released (if it is flagged notify_on_release). Depends on the cgroup_scan_tasks() function (proposed by David Rientjes) to iterate through all tasks in the cpu-less cpuset. We are deliberately avoiding a walk of the tasklist. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Cliff Wickman <cpw@sgi.com> Cc: Paul Menage <menage@google.com> Cc: Paul Jackson <pj@sgi.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>
* cgroups: mechanism to process each task in a cgroupCliff Wickman2008-02-071-12/+186
| | | | | | | | | | | | | | | | | | | Provide cgroup_scan_tasks(), which iterates through every task in a cgroup, calling a test function and a process function for each. And call the process function without holding the css_set_lock lock. The idea is David Rientjes', predicting that such a function will make it much easier in the future to extend things that require access to each task in a cgroup without holding the lock, [akpm@linux-foundation.org: cleanup] [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Cliff Wickman <cpw@sgi.com> Cc: Paul Menage <menage@google.com> Cc: Paul Jackson <pj@sgi.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memory cgroup enhancements: add- pre_destroy() handlerKAMEZAWA Hiroyuki2008-02-071-0/+22
| | | | | | | | | | | | | | | | | | | | | | | | Add a handler "pre_destroy" to cgroup_subsys. It is called before cgroup_rmdir() checks all subsys's refcnt. I think this is useful for subsys which have some extra refs even if there are no tasks in cgroup. By adding pre_destroy(), the kernel keeps the rule "destroy() against subsystem is called only when refcnt=0." and allows css ref to be used by other objects than tasks. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: David Rientjes <rientjes@google.com> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Kirill Korotaev <dev@sw.ru> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Paul Menage <menage@google.com> Cc: Pavel Emelianov <xemul@openvz.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kernel/cgroup.c: make 2 functions staticAdrian Bunk2008-02-071-2/+2
| | | | | | | | | | cgroup_is_releasable() and notify_on_release() should be static, not global inline. Signed-off-by: Adrian Bunk <bunk@kernel.org> Acked-by: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cgroups: move cgroups destroy() callbacks to cgroup_diput()Paul Menage2008-02-071-12/+24
| | | | | | | | | | | | | | | | | Move the calls to the cgroup subsystem destroy() methods from cgroup_rmdir() to cgroup_diput(). This allows control file reads and writes to access their subsystem state without having to be concerned with locking against cgroup destruction - the control file dentry will keep the cgroup and its subsystem state objects alive until the file is closed. The documentation is updated to reflect the changed semantics of destroy(); additionally the locking comments for destroy() and some other methods were clarified and decrustified. Signed-off-by: Paul Menage <menage@google.com> Cc: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cgroup simplify space strippingPaul Jackson2008-02-071-14/+3
| | | | | | | | | | Simplify the space stripping code in cgroup file write. [akpm@linux-foundation.org: s/BUG_ON/BUILD_BUG_ON/] Signed-off-by: Paul Jackson <pj@sgi.com> Acked-by: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cgroup brace coding style fixPaul Jackson2008-02-071-10/+5
| | | | | | | | | Coding style fix - one line conditionals don't get braces. Signed-off-by: Paul Jackson <pj@sgi.com> Acked-by: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kernel/cgroup.c: remove dead codeAdrian Bunk2008-02-071-10/+8
| | | | | | | | | | | This patch removes dead code spotted by the Coverity checker (look at the "(nbytes >= PATH_MAX)" check). Signed-off-by: Adrian Bunk <bunk@kernel.org> Cc: Paul Jackson <pj@sgi.com> Cc: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Improve cgroup printksDiego Calleja2007-11-151-5/+4
| | | | | | | | | | | | | | | | | | | When I boot with the 'quiet' parameter, I see on the screen: [ 0.000000] Initializing cgroup subsys cpuset [ 0.000000] Initializing cgroup subsys cpu [ 39.036026] Initializing cgroup subsys cpuacct [ 39.036080] Initializing cgroup subsys debug [ 39.036118] Initializing cgroup subsys ns This patch lowers the priority of those messages, adds a "cgroup: " prefix to another couple of printks and kills the useless reference to the source file. Signed-off-by: Diego Calleja <diegocg@gmail.com> Cc: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cgroup: kill unused variableJeff Garzik2007-10-241-1/+0
| | | | Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* Control groups: Replace "cont" with "cgrp" and other misc renamingPaul Menage2007-10-191-247/+247
| | | | | | | | | | | | | | | | | Replace "cont" with "cgrp" and other misc renaming This patch finishes some of the names that got missed in the great "task containers" -> "control groups" rename. Primarily it renames the local variable "cont" to "cgrp" in a number of places, and renames the CONT_* enum members to CGRP_*. This patch is not intended to have any effect on the generated code; the output of "objdump -d kernel/cgroup.o" is unchanged. Signed-off-by: Paul Menage <menage@google.com> Acked-by: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Use task_pid_nr() instead of pid_nr(task_pid())Pavel Emelyanov2007-10-191-1/+1
| | | | | | | | | | | There are two places that do so - the cgroups subsystem and the autofs code. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Cc: Ian Kent <raven@themaw.net> Cc: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Add cgroupstatsBalbir Singh2007-10-191-0/+55
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch is inspired by the discussion at http://lkml.org/lkml/2007/4/11/187 and implements per cgroup statistics as suggested by Andrew Morton in http://lkml.org/lkml/2007/4/11/263. The patch is on top of 2.6.21-mm1 with Paul's cgroups v9 patches (forward ported) This patch implements per cgroup statistics infrastructure and re-uses code from the taskstats interface. A new set of cgroup operations are registered with commands and attributes. It should be very easy to *extend* per cgroup statistics, by adding members to the cgroupstats structure. The current model for cgroupstats is a pull, a push model (to post statistics on interesting events), should be very easy to add. Currently user space requests for statistics by passing the cgroup file descriptor. Statistics about the state of all the tasks in the cgroup is returned to user space. TODO's/NOTE: This patch provides an infrastructure for implementing cgroup statistics. Based on the needs of each controller, we can incrementally add more statistics, event based support for notification of statistics, accumulation of taskstats into cgroup statistics in the future. Sample output # ./cgroupstats -C /cgroup/a sleeping 2, blocked 0, running 1, stopped 0, uninterruptible 0 # ./cgroupstats -C /cgroup/ sleeping 154, blocked 0, running 0, stopped 0, uninterruptible 0 If the approach looks good, I'll enhance and post the user space utility for the same Feedback, comments, test results are always welcome! [akpm@linux-foundation.org: build fix] Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Jay Lan <jlan@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Task Control Groups: automatic userspace notification of idle cgroupsPaul Menage2007-10-191-42/+386
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add the following files to the cgroup filesystem: notify_on_release - configures/reports whether the cgroup subsystem should attempt to run a release script when this cgroup becomes unused release_agent - configures/reports the release agent to be used for this hierarchy (top level in each hierarchy only) releasable - reports whether this cgroup would have been auto-released if notify_on_release was true and a release agent was configured (mainly useful for debugging) To avoid locking issues, invoking the userspace release agent is done via a workqueue task; cgroups that need to have their release agents invoked by the workqueue task are linked on to a list. [pj@sgi.com: Need to include kmod.h] 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: Paul Jackson <pj@sgi.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 Menage2007-10-191-114/+535
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 procfs interfacePaul Menage2007-10-191-3/+143
| | | | | | | | | | | | | | | | | | | | | | | Add: /proc/cgroups - general system info /proc/*/cgroup - per-task cgroup membership info [a.p.zijlstra@chello.nl: cgroups: bdi init hooks] 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: 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>
* Task Control Groups: add cgroup_clone() interfacePaul Menage2007-10-191-0/+135
| | | | | | | | | | | | | | | | | | | | Add support for cgroup_clone(), a way to create new cgroups intended to be used for systems such as namespace unsharing. A new subsystem callback, post_clone(), is added to allow subsystems to automatically configure cloned 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>
* Task Control Groups: add fork()/exit() hooksPaul Menage2007-10-191-0/+121
| | | | | | | | | | | | | | | | | | | 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 cgroup write_uint() helper methodPaul Menage2007-10-191-4/+38
| | | | | | | | | | | | Add write_uint() helper method for cgroup subsystems This helper is analagous to the read_uint() helper method for reporting u64 values to userspace. It's designed to reduce the amount of boilerplate requierd for creating new cgroup subsystems. Signed-off-by: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Task Control Groups: add tasks file interfacePaul Menage2007-10-191-1/+358
| | | | | | | | | | | | | | | | | | | | Add the per-directory "tasks" file for cgroupfs mounts; this allows the user to determine which tasks are members of a cgroup by reading a cgroup's "tasks", and to move a task into a cgroup by writing its pid to its "tasks". 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: basic task cgroup frameworkPaul Menage2007-10-191-0/+1198
Generic Process Control Groups -------------------------- There have recently been various proposals floating around for resource management/accounting and other task grouping subsystems in the kernel, including ResGroups, User BeanCounters, NSProxy cgroups, and others. These all need the basic abstraction of being able to group together multiple processes in an aggregate, in order to track/limit the resources permitted to those processes, or control other behaviour of the processes, and all implement this grouping in different ways. This patchset provides a framework for tracking and grouping processes into arbitrary "cgroups" and assigning arbitrary state to those groupings, in order to control the behaviour of the cgroup as an aggregate. The intention is that the various resource management and virtualization/cgroup efforts can also become task cgroup clients, with the result that: - the userspace APIs are (somewhat) normalised - it's easier to test e.g. the ResGroups CPU controller in conjunction with the BeanCounters memory controller, or use either of them as the resource-control portion of a virtual server system. - the additional kernel footprint of any of the competing resource management systems is substantially reduced, since it doesn't need to provide process grouping/containment, hence improving their chances of getting into the kernel This patch: Add the main task cgroups framework - the cgroup filesystem, and the basic structures for tracking membership and associating subsystem state objects to tasks. 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>