19 Mar, 2014
1 commit
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cftype->write_string() just passes on the writeable buffer from kernfs
and there's no reason to add const restriction on the buffer. The
only thing const achieves is unnecessarily complicating parsing of the
buffer. Drop const from @buffer.Signed-off-by: Tejun Heo
Acked-by: Li Zefan
Cc: Peter Zijlstra
Cc: Paul Mackerras
Cc: Ingo Molnar
Cc: Arnaldo Carvalho de Melo
Cc: Daniel Borkmann
Cc: Michal Hocko
Cc: Johannes Weiner
Cc: Balbir Singh
Cc: KAMEZAWA Hiroyuki
08 Feb, 2014
1 commit
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cgroup_subsys is a bit messier than it needs to be.
* The name of a subsys can be different from its internal identifier
defined in cgroup_subsys.h. Most subsystems use the matching name
but three - cpu, memory and perf_event - use different ones.* cgroup_subsys_id enums are postfixed with _subsys_id and each
cgroup_subsys is postfixed with _subsys. cgroup.h is widely
included throughout various subsystems, it doesn't and shouldn't
have claim on such generic names which don't have any qualifier
indicating that they belong to cgroup.* cgroup_subsys->subsys_id should always equal the matching
cgroup_subsys_id enum; however, we require each controller to
initialize it and then BUG if they don't match, which is a bit
silly.This patch cleans up cgroup_subsys names and initialization by doing
the followings.* cgroup_subsys_id enums are now postfixed with _cgrp_id, and each
cgroup_subsys with _cgrp_subsys.* With the above, renaming subsys identifiers to match the userland
visible names doesn't cause any naming conflicts. All non-matching
identifiers are renamed to match the official names.cpu_cgroup -> cpu
mem_cgroup -> memory
perf -> perf_event* controllers no longer need to initialize ->subsys_id and ->name.
They're generated in cgroup core and set automatically during boot.* Redundant cgroup_subsys declarations removed.
* While updating BUG_ON()s in cgroup_init_early(), convert them to
WARN()s. BUGging that early during boot is stupid - the kernel
can't print anything, even through serial console and the trap
handler doesn't even link stack frame properly for back-tracing.This patch doesn't introduce any behavior changes.
v2: Rebased on top of fe1217c4f3f7 ("net: net_cls: move cgroupfs
classid handling into core").Signed-off-by: Tejun Heo
Acked-by: Neil Horman
Acked-by: "David S. Miller"
Acked-by: "Rafael J. Wysocki"
Acked-by: Michal Hocko
Acked-by: Peter Zijlstra
Acked-by: Aristeu Rozanski
Acked-by: Ingo Molnar
Acked-by: Li Zefan
Cc: Johannes Weiner
Cc: Balbir Singh
Cc: KAMEZAWA Hiroyuki
Cc: Serge E. Hallyn
Cc: Vivek Goyal
Cc: Thomas Graf
24 Jan, 2014
1 commit
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Most of the VM_BUG_ON assertions are performed on a page. Usually, when
one of these assertions fails we'll get a BUG_ON with a call stack and
the registers.I've recently noticed based on the requests to add a small piece of code
that dumps the page to various VM_BUG_ON sites that the page dump is
quite useful to people debugging issues in mm.This patch adds a VM_BUG_ON_PAGE(cond, page) which beyond doing what
VM_BUG_ON() does, also dumps the page before executing the actual
BUG_ON.[akpm@linux-foundation.org: fix up includes]
Signed-off-by: Sasha Levin
Cc: "Kirill A. Shutemov"
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
06 Dec, 2013
1 commit
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In preparation of conversion to kernfs, cgroup file handling is being
consolidated so that it can be easily mapped to the seq_file based
interface of kernfs.All users of cftype->read() can be easily served, usually better, by
seq_file and other methods. Update hugetlb_cgroup_read() to return
u64 instead of printing itself and rename it to
hugetlb_cgroup_read_u64().This patch doesn't make any visible behavior changes.
Signed-off-by: Tejun Heo
Reviewed-by: Michal Hocko
Acked-by: Li Zefan
Cc: Aneesh Kumar K.V
Cc: Johannes Weiner
09 Aug, 2013
6 commits
-
cgroup is currently in the process of transitioning to using struct
cgroup_subsys_state * as the primary handle instead of struct cgroup.
Please see the previous commit which converts the subsystem methods
for rationale.This patch converts all cftype file operations to take @css instead of
@cgroup. cftypes for the cgroup core files don't have their subsytem
pointer set. These will automatically use the dummy_css added by the
previous patch and can be converted the same way.Most subsystem conversions are straight forwards but there are some
interesting ones.* freezer: update_if_frozen() is also converted to take @css instead
of @cgroup for consistency. This will make the code look simpler
too once iterators are converted to use css.* memory/vmpressure: mem_cgroup_from_css() needs to be exported to
vmpressure while mem_cgroup_from_cont() can be made static.
Updated accordingly.* cpu: cgroup_tg() doesn't have any user left. Removed.
* cpuacct: cgroup_ca() doesn't have any user left. Removed.
* hugetlb: hugetlb_cgroup_form_cgroup() doesn't have any user left.
Removed.* net_cls: cgrp_cls_state() doesn't have any user left. Removed.
Signed-off-by: Tejun Heo
Acked-by: Li Zefan
Acked-by: Michal Hocko
Acked-by: Vivek Goyal
Acked-by: Aristeu Rozanski
Acked-by: Daniel Wagner
Cc: Peter Zijlstra
Cc: Ingo Molnar
Cc: Johannes Weiner
Cc: Balbir Singh
Cc: Matt Helsley
Cc: Jens Axboe
Cc: Steven Rostedt -
cgroup is currently in the process of transitioning to using struct
cgroup_subsys_state * as the primary handle instead of struct cgroup *
in subsystem implementations for the following reasons.* With unified hierarchy, subsystems will be dynamically bound and
unbound from cgroups and thus css's (cgroup_subsys_state) may be
created and destroyed dynamically over the lifetime of a cgroup,
which is different from the current state where all css's are
allocated and destroyed together with the associated cgroup. This
in turn means that cgroup_css() should be synchronized and may
return NULL, making it more cumbersome to use.* Differing levels of per-subsystem granularity in the unified
hierarchy means that the task and descendant iterators should behave
differently depending on the specific subsystem the iteration is
being performed for.* In majority of the cases, subsystems only care about its part in the
cgroup hierarchy - ie. the hierarchy of css's. Subsystem methods
often obtain the matching css pointer from the cgroup and don't
bother with the cgroup pointer itself. Passing around css fits
much better.This patch converts all cgroup_subsys methods to take @css instead of
@cgroup. The conversions are mostly straight-forward. A few
noteworthy changes are* ->css_alloc() now takes css of the parent cgroup rather than the
pointer to the new cgroup as the css for the new cgroup doesn't
exist yet. Knowing the parent css is enough for all the existing
subsystems.* In kernel/cgroup.c::offline_css(), unnecessary open coded css
dereference is replaced with local variable access.This patch shouldn't cause any behavior differences.
v2: Unnecessary explicit cgrp->subsys[] deref in css_online() replaced
with local variable @css as suggested by Li Zefan.Rebased on top of new for-3.12 which includes for-3.11-fixes so
that ->css_free() invocation added by da0a12caff ("cgroup: fix a
leak when percpu_ref_init() fails") is converted too. Suggested
by Li Zefan.Signed-off-by: Tejun Heo
Acked-by: Li Zefan
Acked-by: Michal Hocko
Acked-by: Vivek Goyal
Acked-by: Aristeu Rozanski
Acked-by: Daniel Wagner
Cc: Peter Zijlstra
Cc: Ingo Molnar
Cc: Johannes Weiner
Cc: Balbir Singh
Cc: Matt Helsley
Cc: Jens Axboe
Cc: Steven Rostedt -
Currently, controllers have to explicitly follow the cgroup hierarchy
to find the parent of a given css. cgroup is moving towards using
cgroup_subsys_state as the main controller interface construct, so
let's provide a way to climb the hierarchy using just csses.This patch implements css_parent() which, given a css, returns its
parent. The function is guarnateed to valid non-NULL parent css as
long as the target css is not at the top of the hierarchy.freezer, cpuset, cpu, cpuacct, hugetlb, memory, net_cls and devices
are converted to use css_parent() instead of accessing cgroup->parent
directly.* __parent_ca() is dropped from cpuacct and its usage is replaced with
parent_ca(). The only difference between the two was NULL test on
cgroup->parent which is now embedded in css_parent() making the
distinction moot. Note that eventually a css->parent field will be
added to css and the NULL check in css_parent() will go away.This patch shouldn't cause any behavior differences.
Signed-off-by: Tejun Heo
Acked-by: Li Zefan -
css (cgroup_subsys_state) is usually embedded in a subsys specific
data structure. Subsystems either use container_of() directly to cast
from css to such data structure or has an accessor function wrapping
such cast. As cgroup as whole is moving towards using css as the main
interface handle, add and update such accessors to ease dealing with
css's.All accessors explicitly handle NULL input and return NULL in those
cases. While this looks like an extra branch in the code, as all
controllers specific data structures have css as the first field, the
casting doesn't involve any offsetting and the compiler can trivially
optimize out the branch.* blkio, freezer, cpuset, cpu, cpuacct and net_cls didn't have such
accessor. Added.* memory, hugetlb and devices already had one but didn't explicitly
handle NULL input. Updated.Signed-off-by: Tejun Heo
Acked-by: Li Zefan -
cgroup controller API will be converted to primarily use struct
cgroup_subsys_state instead of struct cgroup. In preparation, make
hugetlb_cgroup functions pass around struct hugetlb_cgroup instead of
struct cgroup.This patch shouldn't cause any behavior differences.
Signed-off-by: Tejun Heo
Acked-by: Li Zefan
Reviewed-by: Aneesh Kumar K.V
Reviewed-by: Michal Hocko
Cc: KAMEZAWA Hiroyuki
Cc: Johannes Weiner -
The names of the two struct cgroup_subsys_state accessors -
cgroup_subsys_state() and task_subsys_state() - are somewhat awkward.
The former clashes with the type name and the latter doesn't even
indicate it's somehow related to cgroup.We're about to revamp large portion of cgroup API, so, let's rename
them so that they're less awkward. Most per-controller usages of the
accessors are localized in accessor wrappers and given the amount of
scheduled changes, this isn't gonna add any noticeable headache.Rename cgroup_subsys_state() to cgroup_css() and task_subsys_state()
to task_css(). This patch is pure rename.Signed-off-by: Tejun Heo
Acked-by: Li Zefan
19 Dec, 2012
1 commit
-
Build kernel with CONFIG_HUGETLBFS=y,CONFIG_HUGETLB_PAGE=y and
CONFIG_CGROUP_HUGETLB=y, then specify hugepagesz=xx boot option, system
will fail to boot.This failure is caused by following code path:
setup_hugepagesz
hugetlb_add_hstate
hugetlb_cgroup_file_init
cgroup_add_cftypes
kzalloc
Signed-off-by: Jiang Liu
Reviewed-by: Aneesh Kumar K.V
Acked-by: Michal Hocko
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
20 Nov, 2012
1 commit
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Rename cgroup_subsys css lifetime related callbacks to better describe
what their roles are. Also, update documentation.Signed-off-by: Tejun Heo
Acked-by: Li Zefan
06 Nov, 2012
2 commits
-
All ->pre_destory() implementations return 0 now, which is the only
allowed return value. Make it return void.Signed-off-by: Tejun Heo
Reviewed-by: Michal Hocko
Acked-by: KAMEZAWA Hiroyuki
Acked-by: Li Zefan
Cc: Balbir Singh
Cc: Vivek Goyal -
Now that pre_destroy callbacks are called from the context where neither
any task can attach the group nor any children group can be added there
is no other way to fail from hugetlb_pre_destroy.Signed-off-by: Michal Hocko
Reviewed-by: Tejun Heo
Reviewed-by: Glauber Costa
Acked-by: KAMEZAWA Hiroyuki
Signed-off-by: Tejun Heo
01 Aug, 2012
7 commits
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We already hold the hugetlb_lock. That should prevent a parallel cgroup
rmdir from touching page's hugetlb cgroup. So remove the exclude and
wakeup calls.Signed-off-by: Aneesh Kumar K.V
Reviewed-by: Michal Hocko
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
A page's hugetlb cgroup assignment and movement to the active list should
occur with hugetlb_lock held. Otherwise when we remove the hugetlb cgroup
we will iterate the active list and find pages with NULL hugetlb cgroup
values.Signed-off-by: Aneesh Kumar K.V
Reviewed-by: Michal Hocko
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
With HugeTLB pages, hugetlb cgroup is uncharged in compound page
destructor. Since we are holding a hugepage reference, we can be sure
that old page won't get uncharged till the last put_page().Signed-off-by: Aneesh Kumar K.V
Cc: David Rientjes
Acked-by: KAMEZAWA Hiroyuki
Cc: Hillf Danton
Cc: Michal Hocko
Cc: KOSAKI Motohiro
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add the control files for hugetlb controller
[akpm@linux-foundation.org: s/CONFIG_CGROUP_HUGETLB_RES_CTLR/CONFIG_MEMCG_HUGETLB/g]
[akpm@linux-foundation.org: s/CONFIG_MEMCG_HUGETLB/CONFIG_CGROUP_HUGETLB/]
Signed-off-by: Aneesh Kumar K.V
Cc: David Rientjes
Acked-by: KAMEZAWA Hiroyuki
Cc: Hillf Danton
Reviewed-by: Michal Hocko
Cc: KOSAKI Motohiro
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add support for cgroup removal. If we don't have parent cgroup, the
charges are moved to root cgroup.Signed-off-by: Aneesh Kumar K.V
Cc: David Rientjes
Acked-by: KAMEZAWA Hiroyuki
Cc: Hillf Danton
Reviewed-by: Michal Hocko
Cc: KOSAKI Motohiro
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add the charge and uncharge routines for hugetlb cgroup. We do cgroup
charging in page alloc and uncharge in compound page destructor.
Assigning page's hugetlb cgroup is protected by hugetlb_lock.[liwp@linux.vnet.ibm.com: add huge_page_order check to avoid incorrect uncharge]
Signed-off-by: Aneesh Kumar K.V
Cc: David Rientjes
Acked-by: KAMEZAWA Hiroyuki
Cc: Hillf Danton
Cc: Michal Hocko
Cc: KOSAKI Motohiro
Signed-off-by: Aneesh Kumar K.V
Signed-off-by: Wanpeng Li
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Implement a new controller that allows us to control HugeTLB allocations.
The extension allows to limit the HugeTLB usage per control group and
enforces the controller limit during page fault. Since HugeTLB doesn't
support page reclaim, enforcing the limit at page fault time implies that,
the application will get SIGBUS signal if it tries to access HugeTLB pages
beyond its limit. This requires the application to know beforehand how
much HugeTLB pages it would require for its use.The charge/uncharge calls will be added to HugeTLB code in later patch.
Support for cgroup removal will be added in later patches.[akpm@linux-foundation.org: s/CONFIG_CGROUP_HUGETLB_RES_CTLR/CONFIG_MEMCG_HUGETLB/g]
[akpm@linux-foundation.org: s/CONFIG_MEMCG_HUGETLB/CONFIG_CGROUP_HUGETLB/g]
Reviewed-by: KAMEZAWA Hiroyuki
Signed-off-by: Aneesh Kumar K.V
Cc: David Rientjes
Cc: Hillf Danton
Reviewed-by: Michal Hocko
Cc: KOSAKI Motohiro
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
