linux.git/kernel/cpuset.c, branch v3.16-rc3

Merge branch 'for-3.16' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

2014-06-09T22:03:33+00:00

Pull cgroup updates from Tejun Heo:
 "A lot of activities on cgroup side.  Heavy restructuring including
  locking simplification took place to improve the code base and enable
  implementation of the unified hierarchy, which currently exists behind
  a __DEVEL__ mount option.  The core support is mostly complete but
  individual controllers need further work.  To explain the design and
  rationales of the the unified hierarchy

        Documentation/cgroups/unified-hierarchy.txt

  is added.

  Another notable change is css (cgroup_subsys_state - what each
  controller uses to identify and interact with a cgroup) iteration
  update.  This is part of continuing updates on css object lifetime and
  visibility.  cgroup started with reference count draining on removal
  way back and is now reaching a point where csses behave and are
  iterated like normal refcnted objects albeit with some complexities to
  allow distinguishing the state where they're being deleted.  The css
  iteration update isn't taken advantage of yet but is planned to be
  used to simplify memcg significantly"

* 'for-3.16' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (77 commits)
  cgroup: disallow disabled controllers on the default hierarchy
  cgroup: don't destroy the default root
  cgroup: disallow debug controller on the default hierarchy
  cgroup: clean up MAINTAINERS entries
  cgroup: implement css_tryget()
  device_cgroup: use css_has_online_children() instead of has_children()
  cgroup: convert cgroup_has_live_children() into css_has_online_children()
  cgroup: use CSS_ONLINE instead of CGRP_DEAD
  cgroup: iterate cgroup_subsys_states directly
  cgroup: introduce CSS_RELEASED and reduce css iteration fallback window
  cgroup: move cgroup->serial_nr into cgroup_subsys_state
  cgroup: link all cgroup_subsys_states in their sibling lists
  cgroup: move cgroup->sibling and ->children into cgroup_subsys_state
  cgroup: remove cgroup->parent
  device_cgroup: remove direct access to cgroup->children
  memcg: update memcg_has_children() to use css_next_child()
  memcg: remove tasks/children test from mem_cgroup_force_empty()
  cgroup: remove css_parent()
  cgroup: skip refcnting on normal root csses and cgrp_dfl_root self css
  cgroup: use cgroup->self.refcnt for cgroup refcnting
  ...

mm: page_alloc: use jump labels to avoid checking number_of_cpusets

2014-06-04T23:54:08+00:00

If cpusets are not in use then we still check a global variable on every
page allocation.  Use jump labels to avoid the overhead.

Signed-off-by: Mel Gorman 
Reviewed-by: Rik van Riel 
Cc: Johannes Weiner 
Cc: Vlastimil Babka 
Cc: Jan Kara 
Cc: Michal Hocko 
Cc: Hugh Dickins 
Cc: Dave Hansen 
Cc: Theodore Ts'o 
Cc: "Paul E. McKenney" 
Cc: Oleg Nesterov 
Cc: Peter Zijlstra 
Cc: Stephen Rothwell 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

cgroup: remove css_parent()

2014-05-16T17:22:48+00:00

cgroup in general is moving towards using cgroup_subsys_state as the
fundamental structural component and css_parent() was introduced to
convert from using cgroup->parent to css->parent.  It was quite some
time ago and we're moving forward with making css more prominent.

This patch drops the trivial wrapper css_parent() and let the users
dereference css->parent.  While at it, explicitly mark fields of css
which are public and immutable.

v2: New usage from device_cgroup.c converted.

Signed-off-by: Tejun Heo 
Acked-by: Michal Hocko 
Acked-by: Neil Horman 
Acked-by: "David S. Miller" 
Acked-by: Li Zefan 
Cc: Vivek Goyal 
Cc: Jens Axboe 
Cc: Peter Zijlstra 
Cc: Johannes Weiner

cgroup: replace cftype->write_string() with cftype->write()

2014-05-13T16:16:21+00:00

Convert all cftype->write_string() users to the new cftype->write()
which maps directly to kernfs write operation and has full access to
kernfs and cgroup contexts.  The conversions are mostly mechanical.

* @css and @cft are accessed using of_css() and of_cft() accessors
  respectively instead of being specified as arguments.

* Should return @nbytes on success instead of 0.

* @buf is not trimmed automatically.  Trim if necessary.  Note that
  blkcg and netprio don't need this as the parsers already handle
  whitespaces.

cftype->write_string() has no user left after the conversions and
removed.

While at it, remove unnecessary local variable @p in
cgroup_subtree_control_write() and stale comment about
CGROUP_LOCAL_BUFFER_SIZE in cgroup_freezer.c.

This patch doesn't introduce any visible behavior changes.

v2: netprio was missing from conversion.  Converted.

Signed-off-by: Tejun Heo 
Acked-by: Aristeu Rozanski 
Acked-by: Vivek Goyal 
Acked-by: Li Zefan 
Cc: Jens Axboe 
Cc: Johannes Weiner 
Cc: Michal Hocko 
Cc: Neil Horman 
Cc: "David S. Miller"

cgroup: rename css_tryget() to css_tryget_online()

2014-05-13T16:11:01+00:00

Unlike the more usual refcnting, what css_tryget() provides is the
distinction between online and offline csses instead of protection
against upping a refcnt which already reached zero.  cgroup is
planning to provide actual tryget which fails if the refcnt already
reached zero.  Let's rename the existing trygets so that they clearly
indicate that they're onliness.

I thought about keeping the existing names as-are and introducing new
names for the planned actual tryget; however, given that each
controller participates in the synchronization of the online state, it
seems worthwhile to make it explicit that these functions are about
on/offline state.

Rename css_tryget() to css_tryget_online() and css_tryget_from_dir()
to css_tryget_online_from_dir().  This is pure rename.

v2: cgroup_freezer grew new usages of css_tryget().  Update
    accordingly.

Signed-off-by: Tejun Heo 
Acked-by: Johannes Weiner 
Acked-by: Michal Hocko 
Acked-by: Li Zefan 
Cc: Vivek Goyal 
Cc: Jens Axboe 
Cc: Peter Zijlstra 
Cc: Paul Mackerras 
Cc: Ingo Molnar 
Cc: Arnaldo Carvalho de Melo

kernel/cpuset.c: convert printk to pr_foo()

2014-05-06T11:31:14+00:00

Cc: Andrew Morton 
Signed-off-by: Fabian Frederick 
Acked-by: Li Zefan 
Signed-off-by: Tejun Heo

kernel/cpuset.c: kernel-doc fixes

2014-05-06T11:31:14+00:00

This patch also converts seq_printf to seq_puts

Cc: Andrew Morton 
Signed-off-by: Fabian Frederick 
Acked-by: Li Zefan 
Signed-off-by: Tejun Heo

Merge branch 'akpm' (incoming from Andrew)

2014-04-03T23:22:16+00:00

Merge first patch-bomb from Andrew Morton:
 - Various misc bits
 - kmemleak fixes
 - small befs, codafs, cifs, efs, freexxfs, hfsplus, minixfs, reiserfs things
 - fanotify
 - I appear to have become SuperH maintainer
 - ocfs2 updates
 - direct-io tweaks
 - a bit of the MM queue
 - printk updates
 - MAINTAINERS maintenance
 - some backlight things
 - lib/ updates
 - checkpatch updates
 - the rtc queue
 - nilfs2 updates
 - Small Documentation/ updates

* emailed patches from Andrew Morton : (237 commits)
  Documentation/SubmittingPatches: remove references to patch-scripts
  Documentation/SubmittingPatches: update some dead URLs
  Documentation/filesystems/ntfs.txt: remove changelog reference
  Documentation/kmemleak.txt: updates
  fs/reiserfs/super.c: add __init to init_inodecache
  fs/reiserfs: move prototype declaration to header file
  fs/hfsplus/attributes.c: add __init to hfsplus_create_attr_tree_cache()
  fs/hfsplus/extents.c: fix concurrent acess of alloc_blocks
  fs/hfsplus/extents.c: remove unused variable in hfsplus_get_block
  nilfs2: update project's web site in nilfs2.txt
  nilfs2: update MAINTAINERS file entries fix
  nilfs2: verify metadata sizes read from disk
  nilfs2: add FITRIM ioctl support for nilfs2
  nilfs2: add nilfs_sufile_trim_fs to trim clean segs
  nilfs2: implementation of NILFS_IOCTL_SET_SUINFO ioctl
  nilfs2: add nilfs_sufile_set_suinfo to update segment usage
  nilfs2: add struct nilfs_suinfo_update and flags
  nilfs2: update MAINTAINERS file entries
  fs/coda/inode.c: add __init to init_inodecache()
  BEFS: logging cleanup
  ...

mm: optimize put_mems_allowed() usage

2014-04-03T23:20:58+00:00

Since put_mems_allowed() is strictly optional, its a seqcount retry, we
don't need to evaluate the function if the allocation was in fact
successful, saving a smp_rmb some loads and comparisons on some relative
fast-paths.

Since the naming, get/put_mems_allowed() does suggest a mandatory
pairing, rename the interface, as suggested by Mel, to resemble the
seqcount interface.

This gives us: read_mems_allowed_begin() and read_mems_allowed_retry(),
where it is important to note that the return value of the latter call
is inverted from its previous incarnation.

Signed-off-by: Peter Zijlstra 
Signed-off-by: Mel Gorman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'for-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

2014-04-03T20:05:42+00:00

Pull cgroup updates from Tejun Heo:
 "A lot updates for cgroup:

   - The biggest one is cgroup's conversion to kernfs.  cgroup took
     after the long abandoned vfs-entangled sysfs implementation and
     made it even more convoluted over time.  cgroup's internal objects
     were fused with vfs objects which also brought in vfs locking and
     object lifetime rules.  Naturally, there are places where vfs rules
     don't fit and nasty hacks, such as credential switching or lock
     dance interleaving inode mutex and cgroup_mutex with object serial
     number comparison thrown in to decide whether the operation is
     actually necessary, needed to be employed.

     After conversion to kernfs, internal object lifetime and locking
     rules are mostly isolated from vfs interactions allowing shedding
     of several nasty hacks and overall simplification.  This will also
     allow implmentation of operations which may affect multiple cgroups
     which weren't possible before as it would have required nesting
     i_mutexes.

   - Various simplifications including dropping of module support,
     easier cgroup name/path handling, simplified cgroup file type
     handling and task_cg_lists optimization.

   - Prepatory changes for the planned unified hierarchy, which is still
     a patchset away from being actually operational.  The dummy
     hierarchy is updated to serve as the default unified hierarchy.
     Controllers which aren't claimed by other hierarchies are
     associated with it, which BTW was what the dummy hierarchy was for
     anyway.

   - Various fixes from Li and others.  This pull request includes some
     patches to add missing slab.h to various subsystems.  This was
     triggered xattr.h include removal from cgroup.h.  cgroup.h
     indirectly got included a lot of files which brought in xattr.h
     which brought in slab.h.

  There are several merge commits - one to pull in kernfs updates
  necessary for converting cgroup (already in upstream through
  driver-core), others for interfering changes in the fixes branch"

* 'for-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (74 commits)
  cgroup: remove useless argument from cgroup_exit()
  cgroup: fix spurious lockdep warning in cgroup_exit()
  cgroup: Use RCU_INIT_POINTER(x, NULL) in cgroup.c
  cgroup: break kernfs active_ref protection in cgroup directory operations
  cgroup: fix cgroup_taskset walking order
  cgroup: implement CFTYPE_ONLY_ON_DFL
  cgroup: make cgrp_dfl_root mountable
  cgroup: drop const from @buffer of cftype->write_string()
  cgroup: rename cgroup_dummy_root and related names
  cgroup: move ->subsys_mask from cgroupfs_root to cgroup
  cgroup: treat cgroup_dummy_root as an equivalent hierarchy during rebinding
  cgroup: remove NULL checks from [pr_cont_]cgroup_{name|path}()
  cgroup: use cgroup_setup_root() to initialize cgroup_dummy_root
  cgroup: reorganize cgroup bootstrapping
  cgroup: relocate setting of CGRP_DEAD
  cpuset: use rcu_read_lock() to protect task_cs()
  cgroup_freezer: document freezer_fork() subtleties
  cgroup: update cgroup_transfer_tasks() to either succeed or fail
  cgroup: drop task_lock() protection around task->cgroups
  cgroup: update how a newly forked task gets associated with css_set
  ...