03 Nov, 2011
1 commit
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While back-porting Johannes Weiner's patch "mm: memcg-aware global
reclaim" for an internal effort, we noticed a significant performance
regression during page-reclaim heavy workloads due to high contention of
the ss->id_lock. This lock protects idr map, and serializes calls to
idr_get_next() in css_get_next() (which is used during the memcg hierarchy
walk).Since idr_get_next() is just doing a look up, we need only serialize it
with respect to idr_remove()/idr_get_new(). By making the ss->id_lock a
rwlock, contention is greatly reduced and performance improves.Tested: cat a 256m file from a ramdisk in a 128m container 50 times on
each core (one file + container per core) in parallel on a NUMA machine.
Result is the time for the test to complete in 1 of the containers.
Both kernels included Johannes' memcg-aware global reclaim patches.Before rwlock patch: 1710.778s
After rwlock patch: 152.227sSigned-off-by: Andrew Bresticker
Cc: Paul Menage
Cc: Li Zefan
Acked-by: KAMEZAWA Hiroyuki
Cc: Ying Han
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
09 Jul, 2011
1 commit
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Since ca5ecddf (rcu: define __rcu address space modifier for sparse)
rcu_dereference_check use rcu_read_lock_held as a part of condition
automatically so callers do not have to do that as well.Signed-off-by: Michal Hocko
Acked-by: Paul E. McKenney
Signed-off-by: Jiri Kosina
27 May, 2011
2 commits
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The ns_cgroup is an annoying cgroup at the namespace / cgroup frontier and
leads to some problems:* cgroup creation is out-of-control
* cgroup name can conflict when pids are looping
* it is not possible to have a single process handling a lot of
namespaces without falling in a exponential creation time
* we may want to create a namespace without creating a cgroupThe ns_cgroup was replaced by a compatibility flag 'clone_children',
where a newly created cgroup will copy the parent cgroup values.
The userspace has to manually create a cgroup and add a task to
the 'tasks' file.This patch removes the ns_cgroup as suggested in the following thread:
https://lists.linux-foundation.org/pipermail/containers/2009-June/018616.html
The 'cgroup_clone' function is removed because it is no longer used.
This is a userspace-visible change. Commit 45531757b45c ("cgroup: notify
ns_cgroup deprecated") (merged into 2.6.27) caused the kernel to emit a
printk warning users that the feature is planned for removal. Since that
time we have heard from XXX users who were affected by this.Signed-off-by: Daniel Lezcano
Signed-off-by: Serge E. Hallyn
Cc: Eric W. Biederman
Cc: Jamal Hadi Salim
Reviewed-by: Li Zefan
Acked-by: Paul Menage
Acked-by: Matt Helsley
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add cgroup subsystem callbacks for per-thread attachment in atomic contexts
Add can_attach_task(), pre_attach(), and attach_task() as new callbacks
for cgroups's subsystem interface. Unlike can_attach and attach, these
are for per-thread operations, to be called potentially many times when
attaching an entire threadgroup.Also, the old "bool threadgroup" interface is removed, as replaced by
this. All subsystems are modified for the new interface - of note is
cpuset, which requires from/to nodemasks for attach to be globally scoped
(though per-cpuset would work too) to persist from its pre_attach to
attach_task and attach.This is a pre-patch for cgroup-procs-writable.patch.
Signed-off-by: Ben Blum
Cc: "Eric W. Biederman"
Cc: Li Zefan
Cc: Matt Helsley
Reviewed-by: Paul Menage
Cc: Oleg Nesterov
Cc: David Rientjes
Cc: Miao Xie
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
31 Mar, 2011
1 commit
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Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: Lucas De Marchi
16 Feb, 2011
2 commits
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This kernel patch adds the ability to filter monitoring based on
container groups (cgroups). This is for use in per-cpu mode only.The cgroup to monitor is passed as a file descriptor in the pid
argument to the syscall. The file descriptor must be opened to
the cgroup name in the cgroup filesystem. For instance, if the
cgroup name is foo and cgroupfs is mounted in /cgroup, then the
file descriptor is opened to /cgroup/foo. Cgroup mode is
activated by passing PERF_FLAG_PID_CGROUP in the flags argument
to the syscall.For instance to measure in cgroup foo on CPU1 assuming
cgroupfs is mounted under /cgroup:struct perf_event_attr attr;
int cgroup_fd, fd;cgroup_fd = open("/cgroup/foo", O_RDONLY);
fd = perf_event_open(&attr, cgroup_fd, 1, -1, PERF_FLAG_PID_CGROUP);
close(cgroup_fd);Signed-off-by: Stephane Eranian
[ added perf_cgroup_{exit,attach} ]
Signed-off-by: Peter Zijlstra
LKML-Reference:
Signed-off-by: Ingo Molnar -
Make the ::exit method act like ::attach, it is after all very nearly
the same thing.The bug had no effect on correctness - fixing it is an optimization for
the scheduler. Also, later perf-cgroups patches rely on it.Signed-off-by: Peter Zijlstra
Acked-by: Paul Menage
LKML-Reference:
Signed-off-by: Ingo Molnar
02 Nov, 2010
1 commit
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"gadget", "through", "command", "maintain", "maintain", "controller", "address",
"between", "initiali[zs]e", "instead", "function", "select", "already",
"equal", "access", "management", "hierarchy", "registration", "interest",
"relative", "memory", "offset", "already",Signed-off-by: Uwe Kleine-König
Signed-off-by: Jiri Kosina
28 Oct, 2010
1 commit
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The ns_cgroup is a control group interacting with the namespaces. When a
new namespace is created, a corresponding cgroup is automatically created
too. The cgroup name is the pid of the process who did 'unshare' or the
child of 'clone'.This cgroup is tied with the namespace because it prevents a process to
escape the control group and use the post_clone callback, so the child
cgroup inherits the values of the parent cgroup.Unfortunately, the more we use this cgroup and the more we are facing
problems with it:(1) when a process unshares, the cgroup name may conflict with a
previous cgroup with the same pid, so unshare or clone return -EEXIST(2) the cgroup creation is out of control because there may have an
application creating several namespaces where the system will
automatically create several cgroups in his back and let them on the
cgroupfs (eg. a vrf based on the network namespace).(3) the mix of (1) and (2) force an administrator to regularly check
and clean these cgroups.This patchset removes the ns_cgroup by adding a new flag to the cgroup and
the cgroupfs mount option. It enables the copy of the parent cgroup when
a child cgroup is created. We can then safely remove the ns_cgroup as
this flag brings a compatibility. We have now to manually create and add
the task to a cgroup, which is consistent with the cgroup framework.This patch:
Sent as an answer to a previous thread around the ns_cgroup.
https://lists.linux-foundation.org/pipermail/containers/2009-June/018627.html
It adds a control file 'clone_children' for a cgroup. This control file
is a boolean specifying if the child cgroup should be a clone of the
parent cgroup or not. The default value is 'false'.This flag makes the child cgroup to call the post_clone callback of all
the subsystem, if it is available.At present, the cpuset is the only one which had implemented the
post_clone callback.The option can be set at mount time by specifying the 'clone_children'
mount option.Signed-off-by: Daniel Lezcano
Signed-off-by: Serge E. Hallyn
Cc: Eric W. Biederman
Acked-by: Paul Menage
Reviewed-by: Li Zefan
Cc: Jamal Hadi Salim
Cc: Matt Helsley
Acked-by: Balbir Singh
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
07 Oct, 2010
1 commit
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…ck/linux-2.6-rcu into core/rcu
10 Sep, 2010
1 commit
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Add cgroup_attach_task_all()
The existing cgroup_attach_task_current_cg() API is called by a thread to
attach another thread to all of its cgroups; this is unsuitable for cases
where a privileged task wants to attach itself to the cgroups of a less
privileged one, since the call must be made from the context of the target
task.This patch adds a more generic cgroup_attach_task_all() API that allows
both the source task and to-be-moved task to be specified.
cgroup_attach_task_current_cg() becomes a specialization of the more
generic new function.[menage@google.com: rewrote changelog]
[akpm@linux-foundation.org: address reviewer comments]
Signed-off-by: Michael S. Tsirkin
Tested-by: Alex Williamson
Acked-by: Paul Menage
Cc: Li Zefan
Cc: Ben Blum
Cc: Sridhar Samudrala
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
20 Aug, 2010
1 commit
-
Signed-off-by: Arnd Bergmann
Signed-off-by: Paul E. McKenney
Acked-by: Paul Menage
Cc: Li Zefan
Reviewed-by: Josh Triplett
05 Aug, 2010
1 commit
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* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1443 commits)
phy/marvell: add 88ec048 support
igb: Program MDICNFG register prior to PHY init
e1000e: correct MAC-PHY interconnect register offset for 82579
hso: Add new product ID
can: Add driver for esd CAN-USB/2 device
l2tp: fix export of header file for userspace
can-raw: Fix skb_orphan_try handling
Revert "net: remove zap_completion_queue"
net: cleanup inclusion
phy/marvell: add 88e1121 interface mode support
u32: negative offset fix
net: Fix a typo from "dev" to "ndev"
igb: Use irq_synchronize per vector when using MSI-X
ixgbevf: fix null pointer dereference due to filter being set for VLAN 0
e1000e: Fix irq_synchronize in MSI-X case
e1000e: register pm_qos request on hardware activation
ip_fragment: fix subtracting PPPOE_SES_HLEN from mtu twice
net: Add getsockopt support for TCP thin-streams
cxgb4: update driver version
cxgb4: add new PCI IDs
...Manually fix up conflicts in:
- drivers/net/e1000e/netdev.c: due to pm_qos registration
infrastructure changes
- drivers/net/phy/marvell.c: conflict between adding 88ec048 support
and cleaning up the IDs
- drivers/net/wireless/ipw2x00/ipw2100.c: trivial ipw2100_pm_qos_req
conflict (registration change vs marking it static)
28 Jul, 2010
1 commit
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Add a new kernel API to attach a task to current task's cgroup
in all the active hierarchies.Signed-off-by: Sridhar Samudrala
Signed-off-by: Michael S. Tsirkin
Reviewed-by: Paul Menage
Acked-by: Li Zefan
09 Jun, 2010
1 commit
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PROVE_RCU has a few issues with the cpu_cgroup because the scheduler
typically holds rq->lock around the css rcu derefs but the generic
cgroup code doesn't (and can't) know about that lock.Provide means to add extra checks to the css dereference and use that
in the scheduler to annotate its users.The addition of rq->lock to these checks is correct because the
cgroup_subsys::attach() method takes the rq->lock for each task it
moves, therefore by holding that lock, we ensure the task is pinned to
the current cgroup and the RCU derefence is valid.That leaves one genuine race in __sched_setscheduler() where we used
task_group() without holding any of the required locks and thus raced
with the cgroup code. Solve this by moving the check under the
appropriate lock.Signed-off-by: Peter Zijlstra
Cc: "Paul E. McKenney"
LKML-Reference:
Signed-off-by: Ingo Molnar
28 May, 2010
1 commit
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Since we are unable to handle an error returned by
cftype.unregister_event() properly, let's make the callback
void-returning.mem_cgroup_unregister_event() has been rewritten to be a "never fail"
function. On mem_cgroup_usage_register_event() we save old buffer for
thresholds array and reuse it in mem_cgroup_usage_unregister_event() to
avoid allocation.Signed-off-by: Kirill A. Shutemov
Acked-by: KAMEZAWA Hiroyuki
Cc: Phil Carmody
Cc: Balbir Singh
Cc: Daisuke Nishimura
Cc: Paul Menage
Cc: Li Zefan
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
05 May, 2010
1 commit
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Expand task_subsys_state()'s rcu_dereference_check() to include the full
locking rule as documented in Documentation/cgroups/cgroups.txt by adding
a check for task->alloc_lock being held.This fixes an RCU false positive when resuming from suspend. The warning
comes from freezer cgroup in cgroup_freezing_or_frozen().Signed-off-by: Li Zefan
Acked-by: Matt Helsley
Signed-off-by: Paul E. McKenney
13 Mar, 2010
7 commits
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Events should be removed after rmdir of cgroup directory, but before
destroying subsystem state objects. Let's take reference to cgroup
directory dentry to do that.Signed-off-by: Kirill A. Shutemov
Acked-by: KAMEZAWA Hiroyuki
Cc: Paul Menage
Acked-by: Li Zefan
Cc: Balbir Singh
Cc: Pavel Emelyanov
Cc: Dan Malek
Cc: Daisuke Nishimura
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This patchset introduces eventfd-based API for notifications in cgroups
and implements memory notifications on top of it.It uses statistics in memory controler to track memory usage.
Output of time(1) on building kernel on tmpfs:
Root cgroup before changes:
make -j2 506.37 user 60.93s system 193% cpu 4:52.77 total
Non-root cgroup before changes:
make -j2 507.14 user 62.66s system 193% cpu 4:54.74 total
Root cgroup after changes (0 thresholds):
make -j2 507.13 user 62.20s system 193% cpu 4:53.55 total
Non-root cgroup after changes (0 thresholds):
make -j2 507.70 user 64.20s system 193% cpu 4:55.70 total
Root cgroup after changes (1 thresholds, never crossed):
make -j2 506.97 user 62.20s system 193% cpu 4:53.90 total
Non-root cgroup after changes (1 thresholds, never crossed):
make -j2 507.55 user 64.08s system 193% cpu 4:55.63 totalThis patch:
Introduce the write-only file "cgroup.event_control" in every cgroup.
To register new notification handler you need:
- create an eventfd;
- open a control file to be monitored. Callbacks register_event() and
unregister_event() must be defined for the control file;
- write " " to cgroup.event_control.
Interpretation of args is defined by control file implementation;eventfd will be woken up by control file implementation or when the
cgroup is removed.To unregister notification handler just close eventfd.
If you need notification functionality for a control file you have to
implement callbacks register_event() and unregister_event() in the
struct cftype.[kamezawa.hiroyu@jp.fujitsu.com: Kconfig fix]
Signed-off-by: Kirill A. Shutemov
Reviewed-by: KAMEZAWA Hiroyuki
Paul Menage
Cc: Li Zefan
Cc: Balbir Singh
Cc: Pavel Emelyanov
Cc: Dan Malek
Cc: Vladislav Buzov
Cc: Daisuke Nishimura
Cc: Alexander Shishkin
Cc: Davide Libenzi
Signed-off-by: KAMEZAWA Hiroyuki
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Provides support for unloading modular subsystems.
This patch adds a new function cgroup_unload_subsys which is to be used
for removing a loaded subsystem during module deletion. Reference
counting of the subsystems' modules is moved from once (at load time) to
once per attached hierarchy (in parse_cgroupfs_options and
rebind_subsystems) (i.e., 0 or 1).Signed-off-by: Ben Blum
Acked-by: Li Zefan
Cc: Paul Menage
Cc: "David S. Miller"
Cc: KAMEZAWA Hiroyuki
Cc: Lai Jiangshan
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add interface between cgroups subsystem management and module loading
This patch implements rudimentary module-loading support for cgroups -
namely, a cgroup_load_subsys (similar to cgroup_init_subsys) for use as a
module initcall, and a struct module pointer in struct cgroup_subsys.Several functions that might be wanted by modules have had EXPORT_SYMBOL
added to them, but it's unclear exactly which functions want it and which
won't.Signed-off-by: Ben Blum
Acked-by: Li Zefan
Cc: Paul Menage
Cc: "David S. Miller"
Cc: KAMEZAWA Hiroyuki
Cc: Lai Jiangshan
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This patch series provides the ability for cgroup subsystems to be
compiled as modules both within and outside the kernel tree. This is
mainly useful for classifiers and subsystems that hook into components
that are already modules. cls_cgroup and blkio-cgroup serve as the
example use cases for this feature.It provides an interface cgroup_load_subsys() and cgroup_unload_subsys()
which modular subsystems can use to register and depart during runtime.
The net_cls classifier subsystem serves as the example for a subsystem
which can be converted into a module using these changes.Patch #1 sets up the subsys[] array so its contents can be dynamic as
modules appear and (eventually) disappear. Iterations over the array are
modified to handle when subsystems are absent, and the dynamic section of
the array is protected by cgroup_mutex.Patch #2 implements an interface for modules to load subsystems, called
cgroup_load_subsys, similar to cgroup_init_subsys, and adds a module
pointer in struct cgroup_subsys.Patch #3 adds a mechanism for unloading modular subsystems, which includes
a more advanced rework of the rudimentary reference counting introduced in
patch 2.Patch #4 modifies the net_cls subsystem, which already had some module
declarations, to be configurable as a module, which also serves as a
simple proof-of-concept.Part of implementing patches 2 and 4 involved updating css pointers in
each css_set when the module appears or leaves. In doing this, it was
discovered that css_sets always remain linked to the dummy cgroup,
regardless of whether or not any subsystems are actually bound to it
(i.e., not mounted on an actual hierarchy). The subsystem loading and
unloading code therefore should keep in mind the special cases where the
added subsystem is the only one in the dummy cgroup (and therefore all
css_sets need to be linked back into it) and where the removed subsys was
the only one in the dummy cgroup (and therefore all css_sets should be
unlinked from it) - however, as all css_sets always stay attached to the
dummy cgroup anyway, these cases are ignored. Any fix that addresses this
issue should also make sure these cases are addressed in the subsystem
loading and unloading code.This patch:
Make subsys[] able to be dynamically populated to support modular
subsystemsThis patch reworks the way the subsys[] array is used so that subsystems
can register themselves after boot time, and enables the internals of
cgroups to be able to handle when subsystems are not present or may
appear/disappear.Signed-off-by: Ben Blum
Acked-by: Li Zefan
Cc: Paul Menage
Cc: "David S. Miller"
Cc: KAMEZAWA Hiroyuki
Cc: Lai Jiangshan
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Current css_get() and css_put() increment/decrement css->refcnt one by
one.This patch add a new function __css_get(), which takes "count" as a arg
and increment the css->refcnt by "count". And this patch also add a new
arg("count") to __css_put() and change the function to decrement the
css->refcnt by "count".These coalesce version of __css_get()/__css_put() will be used to improve
performance of memcg's moving charge feature later, where instead of
calling css_get()/css_put() repeatedly, these new functions will be used.No change is needed for current users of css_get()/css_put().
Signed-off-by: Daisuke Nishimura
Acked-by: Paul Menage
Cc: Balbir Singh
Acked-by: KAMEZAWA Hiroyuki
Cc: Li Zefan
Cc: Daisuke Nishimura
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add cancel_attach() operation to struct cgroup_subsys. cancel_attach()
can be used when can_attach() operation prepares something for the subsys,
but we should rollback what can_attach() operation has prepared if attach
task fails after we've succeeded in can_attach().Signed-off-by: Daisuke Nishimura
Acked-by: Li Zefan
Reviewed-by: Paul Menage
Cc: Balbir Singh
Acked-by: KAMEZAWA Hiroyuki
Cc: Daisuke Nishimura
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
25 Feb, 2010
1 commit
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Update the rcu_dereference() usages to take advantage of the new
lockdep-based checking.Signed-off-by: Paul E. McKenney
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference:
[ -v2: fix allmodconfig missing symbol export build failure on x86 ]
Signed-off-by: Ingo Molnar
02 Oct, 2009
1 commit
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[akpm@linux-foundation.org: fix KVM]
Signed-off-by: Alexey Dobriyan
Acked-by: Mike Frysinger
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
24 Sep, 2009
5 commits
-
Alter the ss->can_attach and ss->attach functions to be able to deal with
a whole threadgroup at a time, for use in cgroup_attach_proc. (This is a
pre-patch to cgroup-procs-writable.patch.)Currently, new mode of the attach function can only tell the subsystem
about the old cgroup of the threadgroup leader. No subsystem currently
needs that information for each thread that's being moved, but if one were
to be added (for example, one that counts tasks within a group) this bit
would need to be reworked a bit to tell the subsystem the right
information.[hidave.darkstar@gmail.com: fix build]
Signed-off-by: Ben Blum
Signed-off-by: Paul Menage
Acked-by: Li Zefan
Reviewed-by: Matt Helsley
Cc: "Eric W. Biederman"
Cc: Oleg Nesterov
Cc: Peter Zijlstra
Cc: Ingo Molnar
Cc: Dave Young
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Changes css_set freeing mechanism to be under RCU
This is a prepatch for making the procs file writable. In order to free the
old css_sets for each task to be moved as they're being moved, the freeing
mechanism must be RCU-protected, or else we would have to have a call to
synchronize_rcu() for each task before freeing its old css_set.Signed-off-by: Ben Blum
Signed-off-by: Paul Menage
Cc: "Paul E. McKenney"
Acked-by: Li Zefan
Cc: Matt Helsley
Cc: "Eric W. Biederman"
Cc: Oleg Nesterov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Previously there was the problem in which two processes from different pid
namespaces reading the tasks or procs file could result in one process
seeing results from the other's namespace. Rather than one pidlist for
each file in a cgroup, we now keep a list of pidlists keyed by namespace
and file type (tasks versus procs) in which entries are placed on demand.
Each pidlist has its own lock, and that the pidlists themselves are passed
around in the seq_file's private pointer means we don't have to touch the
cgroup or its master list except when creating and destroying entries.Signed-off-by: Ben Blum
Signed-off-by: Paul Menage
Cc: Li Zefan
Cc: Matt Helsley
Cc: "Eric W. Biederman"
Cc: Oleg Nesterov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
struct cgroup used to have a bunch of fields for keeping track of the
pidlist for the tasks file. Those are now separated into a new struct
cgroup_pidlist, of which two are had, one for procs and one for tasks.
The way the seq_file operations are set up is changed so that just the
pidlist struct gets passed around as the private data.Interface example: Suppose a multithreaded process has pid 1000 and other
threads with ids 1001, 1002, 1003:
$ cat tasks
1000
1001
1002
1003
$ cat cgroup.procs
1000
$Signed-off-by: Ben Blum
Signed-off-by: Paul Menage
Acked-by: Li Zefan
Cc: Matt Helsley
Cc: "Eric W. Biederman"
Cc: Oleg Nesterov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The following series adds a "cgroup.procs" file to each cgroup that
reports unique tgids rather than pids, and allows all threads in a
threadgroup to be atomically moved to a new cgroup.The subsystem "attach" interface is modified to support attaching whole
threadgroups at a time, which could introduce potential problems if any
subsystem were to need to access the old cgroup of every thread being
moved. The attach interface may need to be revised if this becomes the
case.Also added is functionality for read/write locking all CLONE_THREAD
fork()ing within a threadgroup, by means of an rwsem that lives in the
sighand_struct, for per-threadgroup-ness and also for sharing a cacheline
with the sighand's atomic count. This scheme should introduce no extra
overhead in the fork path when there's no contention.The final patch reveals potential for a race when forking before a
subsystem's attach function is called - one potential solution in case any
subsystem has this problem is to hang on to the group's fork mutex through
the attach() calls, though no subsystem yet demonstrates need for an
extended critical section.This patch:
Revert
commit 096b7fe012d66ed55e98bc8022405ede0cc80e96
Author: Li Zefan
AuthorDate: Wed Jul 29 15:04:04 2009 -0700
Commit: Linus Torvalds
CommitDate: Wed Jul 29 19:10:35 2009 -0700cgroups: fix pid namespace bug
This is in preparation for some clashing cgroups changes that subsume the
original commit's functionaliy.The original commit fixed a pid namespace bug which Ben Blum fixed
independently (in the same way, but with different code) as part of a
series of patches. I played around with trying to reconcile Ben's patch
series with Li's patch, but concluded that it was simpler to just revert
Li's, given that Ben's patch series contained essentially the same fix.Signed-off-by: Paul Menage
Cc: Li Zefan
Cc: Matt Helsley
Cc: "Eric W. Biederman"
Cc: Oleg Nesterov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
30 Jul, 2009
2 commits
-
After commit ec64f51545fffbc4cb968f0cea56341a4b07e85a ("cgroup: fix
frequent -EBUSY at rmdir"), cgroup's rmdir (especially against memcg)
doesn't return -EBUSY by temporary ref counts. That commit expects all
refs after pre_destroy() is temporary but...it wasn't. Then, rmdir can
wait permanently. This patch tries to fix that and change followings.- set CGRP_WAIT_ON_RMDIR flag before pre_destroy().
- clear CGRP_WAIT_ON_RMDIR flag when the subsys finds racy case.
if there are sleeping ones, wakes them up.
- rmdir() sleeps only when CGRP_WAIT_ON_RMDIR flag is set.Tested-by: Daisuke Nishimura
Reported-by: Daisuke Nishimura
Reviewed-by: Paul Menage
Acked-by: Balbir Sigh
Signed-off-by: KAMEZAWA Hiroyuki
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The bug was introduced by commit cc31edceee04a7b87f2be48f9489ebb72d264844
("cgroups: convert tasks file to use a seq_file with shared pid array").We cache a pid array for all threads that are opening the same "tasks"
file, but the pids in the array are always from the namespace of the
last process that opened the file, so all other threads will read pids
from that namespace instead of their own namespaces.To fix it, we maintain a list of pid arrays, which is keyed by pid_ns.
The list will be of length 1 at most time.Reported-by: Paul Menage
Idea-by: Paul Menage
Signed-off-by: Li Zefan
Reviewed-by: Serge Hallyn
Cc: Balbir Singh
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
04 Apr, 2009
1 commit
-
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (28 commits)
trivial: Update my email address
trivial: NULL noise: drivers/mtd/tests/mtd_*test.c
trivial: NULL noise: drivers/media/dvb/frontends/drx397xD_fw.h
trivial: Fix misspelling of "Celsius".
trivial: remove unused variable 'path' in alloc_file()
trivial: fix a pdlfush -> pdflush typo in comment
trivial: jbd header comment typo fix for JBD_PARANOID_IOFAIL
trivial: wusb: Storage class should be before const qualifier
trivial: drivers/char/bsr.c: Storage class should be before const qualifier
trivial: h8300: Storage class should be before const qualifier
trivial: fix where cgroup documentation is not correctly referred to
trivial: Give the right path in Documentation example
trivial: MTD: remove EOL from MODULE_DESCRIPTION
trivial: Fix typo in bio_split()'s documentation
trivial: PWM: fix of #endif comment
trivial: fix typos/grammar errors in Kconfig texts
trivial: Fix misspelling of firmware
trivial: cgroups: documentation typo and spelling corrections
trivial: Update contact info for Jochen Hein
trivial: fix typo "resgister" -> "register"
...
03 Apr, 2009
6 commits
-
We need to pass some data to test_task() or process_task() in some cases.
Will be used later.Signed-off-by: Li Zefan
Cc: KAMEZAWA Hiroyuki
Cc: Paul Menage
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This patch tries to fix OOM Killer problems caused by hierarchy.
Now, memcg itself has OOM KILL function (in oom_kill.c) and tries to
kill a task in memcg.But, when hierarchy is used, it's broken and correct task cannot
be killed. For example, in following cgroup/groupA/ hierarchy=1, limit=1G,
01 nolimit
02 nolimit
All tasks' memory usage under /groupA, /groupA/01, groupA/02 is limited to
groupA's 1Gbytes but OOM Killer just kills tasks in groupA.This patch provides makes the bad process be selected from all tasks
under hierarchy. BTW, currently, oom_jiffies is updated against groupA
in above case. oom_jiffies of tree should be updated.To see how oom_jiffies is used, please check mem_cgroup_oom_called()
callers.[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: const fix]
Signed-off-by: KAMEZAWA Hiroyuki
Cc: Paul Menage
Cc: Li Zefan
Cc: Balbir Singh
Cc: Daisuke Nishimura
Cc: David Rientjes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
We have some read-only files and write-only files, but currently they are
all set to 0644, which is counter-intuitive and cause trouble for some
cgroup tools like libcgroup.This patch adds 'mode' to struct cftype to allow cgroup subsys to set it's
own files' file mode, and for the most cases cft->mode can be default to 0
and cgroup will figure out proper mode.Acked-by: Paul Menage
Reviewed-by: KAMEZAWA Hiroyuki
Signed-off-by: Li Zefan
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
In following situation, with memory subsystem,
/groupA use_hierarchy==1
/01 some tasks
/02 some tasks
/03 some tasks
/04 emptyWhen tasks under 01/02/03 hit limit on /groupA, hierarchical reclaim
is triggered and the kernel walks tree under groupA. In this case,
rmdir /groupA/04 fails with -EBUSY frequently because of temporal
refcnt from the kernel.In general. cgroup can be rmdir'd if there are no children groups and
no tasks. Frequent fails of rmdir() is not useful to users.
(And the reason for -EBUSY is unknown to users.....in most cases)This patch tries to modify above behavior, by
- retries if css_refcnt is got by someone.
- add "return value" to pre_destroy() and allows subsystem to
say "we're really busy!"Signed-off-by: KAMEZAWA Hiroyuki
Cc: Paul Menage
Cc: Li Zefan
Cc: Balbir Singh
Cc: Daisuke Nishimura
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Patch for Per-CSS(Cgroup Subsys State) ID and private hierarchy code.
This patch attaches unique ID to each css and provides following.
- css_lookup(subsys, id)
returns pointer to struct cgroup_subysys_state of id.
- css_get_next(subsys, id, rootid, depth, foundid)
returns the next css under "root" by scanningWhen cgroup_subsys->use_id is set, an id for css is maintained.
The cgroup framework only parepares
- css_id of root css for subsys
- id is automatically attached at creation of css.
- id is *not* freed automatically. Because the cgroup framework
don't know lifetime of cgroup_subsys_state.
free_css_id() function is provided. This must be called by subsys.There are several reasons to develop this.
- Saving space .... For example, memcg's swap_cgroup is array of
pointers to cgroup. But it is not necessary to be very fast.
By replacing pointers(8bytes per ent) to ID (2byes per ent), we can
reduce much amount of memory usage.- Scanning without lock.
CSS_ID provides "scan id under this ROOT" function. By this, scanning
css under root can be written without locks.
ex)
do {
rcu_read_lock();
next = cgroup_get_next(subsys, id, root, &found);
/* check sanity of next here */
css_tryget();
rcu_read_unlock();
id = found + 1
} while(...)Characteristics:
- Each css has unique ID under subsys.
- Lifetime of ID is controlled by subsys.
- css ID contains "ID" and "Depth in hierarchy" and stack of hierarchy
- Allowed ID is 1-65535, ID 0 is UNUSED ID.Design Choices:
- scan-by-ID v.s. scan-by-tree-walk.
As /proc's pid scan does, scan-by-ID is robust when scanning is done
by following kind of routine.
scan -> rest a while(release a lock) -> conitunue from interrupted
memcg's hierarchical reclaim does this.- When subsys->use_id is set, # of css in the system is limited to
65535.[bharata@linux.vnet.ibm.com: remove rcu_read_lock() from css_get_next()]
Signed-off-by: KAMEZAWA Hiroyuki
Acked-by: Paul Menage
Cc: Li Zefan
Cc: Balbir Singh
Cc: Daisuke Nishimura
Signed-off-by: Bharata B Rao
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The ns_proxy cgroup allows moving processes to child cgroups only one
level deep at a time. This commit relaxes this restriction and makes it
possible to attach tasks directly to grandchild cgroups, e.g.:($pid is in the root cgroup)
echo $pid > /cgroup/CG1/CG2/tasksPreviously this operation would fail with -EPERM and would have to be
performed as two steps:
echo $pid > /cgroup/CG1/tasks
echo $pid > /cgroup/CG1/CG2/tasksAlso, the target cgroup no longer needs to be empty to move a task there.
Signed-off-by: Grzegorz Nosek
Acked-by: Serge Hallyn
Reviewed-by: Li Zefan
Cc: Paul Menage
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
