1. 09 8月, 2013 14 次提交
    • T
      cgroup: make task iterators deal with cgroup_subsys_state instead of cgroup · 72ec7029
      Tejun Heo 提交于
      cgroup is in the process of converting to css (cgroup_subsys_state)
      from cgroup as the principal subsystem interface handle.  This is
      mostly to prepare for the unified hierarchy support where css's will
      be created and destroyed dynamically but also helps cleaning up
      subsystem implementations as css is usually what they are interested
      in anyway.
      
      This patch converts task iterators to deal with css instead of cgroup.
      Note that under unified hierarchy, different sets of tasks will be
      considered belonging to a given cgroup depending on the subsystem in
      question and making the iterators deal with css instead cgroup
      provides them with enough information about the iteration.
      
      While at it, fix several function comment formats in cpuset.c.
      
      This patch doesn't introduce any behavior differences.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Acked-by: NLi Zefan <lizefan@huawei.com>
      Acked-by: NMichal Hocko <mhocko@suse.cz>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Balbir Singh <bsingharora@gmail.com>
      Cc: Matt Helsley <matthltc@us.ibm.com>
      72ec7029
    • T
      cgroup: remove struct cgroup_scanner · e535837b
      Tejun Heo 提交于
      cgroup_scan_tasks() takes a pointer to struct cgroup_scanner as its
      sole argument and the only function of that struct is packing the
      arguments of the function call which are consisted of five fields.
      It's not too unusual to pack parameters into a struct when the number
      of arguments gets excessive or the whole set needs to be passed around
      a lot, but neither holds here making it just weird.
      
      Drop struct cgroup_scanner and pass the params directly to
      cgroup_scan_tasks().  Note that struct cpuset_change_nodemask_arg was
      added to cpuset.c to pass both ->cs and ->newmems pointer to
      cpuset_change_nodemask() using single data pointer.
      
      This doesn't make any functional differences.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Acked-by: NLi Zefan <lizefan@huawei.com>
      e535837b
    • T
      cgroup: make cgroup_task_iter remember the cgroup being iterated · c59cd3d8
      Tejun Heo 提交于
      Currently all cgroup_task_iter functions require @cgrp to be passed
      in, which is superflous and increases chance of usage error.  Make
      cgroup_task_iter remember the cgroup being iterated and drop @cgrp
      argument from next and end functions.
      
      This patch doesn't introduce any behavior differences.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Acked-by: NLi Zefan <lizefan@huawei.com>
      Acked-by: NMichal Hocko <mhocko@suse.cz>
      Cc: Matt Helsley <matthltc@us.ibm.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Balbir Singh <bsingharora@gmail.com>
      c59cd3d8
    • T
      cgroup: rename cgroup_iter to cgroup_task_iter · 0942eeee
      Tejun Heo 提交于
      cgroup now has multiple iterators and it's quite confusing to have
      something which walks over tasks of a single cgroup named cgroup_iter.
      Let's rename it to cgroup_task_iter.
      
      While at it, reformat / update comments and replace the overview
      comment above the interface function decls with proper function
      comments.  Such overview can be useful but function comments should be
      more than enough here.
      
      This is pure rename and doesn't introduce any functional changes.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Acked-by: NLi Zefan <lizefan@huawei.com>
      Acked-by: NMichal Hocko <mhocko@suse.cz>
      Cc: Matt Helsley <matthltc@us.ibm.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Balbir Singh <bsingharora@gmail.com>
      0942eeee
    • T
      cgroup: make hierarchy iterators deal with cgroup_subsys_state instead of cgroup · 492eb21b
      Tejun Heo 提交于
      cgroup is currently in the process of transitioning to using css
      (cgroup_subsys_state) as the primary handle instead of cgroup in
      subsystem API.  For hierarchy iterators, this is beneficial because
      
      * In most cases, css is the only thing subsystems care about anyway.
      
      * On the planned unified hierarchy, iterations for different
        subsystems will need to skip over different subtrees of the
        hierarchy depending on which subsystems are enabled on each cgroup.
        Passing around css makes it unnecessary to explicitly specify the
        subsystem in question as css is intersection between cgroup and
        subsystem
      
      * For the planned unified hierarchy, css's would need to be created
        and destroyed dynamically independent from cgroup hierarchy.  Having
        cgroup core manage css iteration makes enforcing deref rules a lot
        easier.
      
      Most subsystem conversions are straight-forward.  Noteworthy changes
      are
      
      * blkio: cgroup_to_blkcg() is no longer used.  Removed.
      
      * freezer: cgroup_freezer() is no longer used.  Removed.
      
      * devices: cgroup_to_devcgroup() is no longer used.  Removed.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Acked-by: NLi Zefan <lizefan@huawei.com>
      Acked-by: NMichal Hocko <mhocko@suse.cz>
      Acked-by: NVivek Goyal <vgoyal@redhat.com>
      Acked-by: NAristeu Rozanski <aris@redhat.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Balbir Singh <bsingharora@gmail.com>
      Cc: Matt Helsley <matthltc@us.ibm.com>
      Cc: Jens Axboe <axboe@kernel.dk>
      492eb21b
    • T
      cgroup: always use cgroup_next_child() to walk the children list · f48e3924
      Tejun Heo 提交于
      There are several places where the children list is accessed directly.
      This patch converts those places to use cgroup_next_child().  This
      will help updating the hierarchy iterators to use @css instead of
      @cgrp.
      
      While cgroup_next_child() can be heavy in pathological cases - e.g. a
      lot of dead children, this shouldn't cause any noticeable behavior
      differences.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Acked-by: NLi Zefan <lizefan@huawei.com>
      f48e3924
    • T
      cgroup: convert cgroup_next_sibling() to cgroup_next_child() · 3b287a50
      Tejun Heo 提交于
      cgroup is transitioning to using css (cgroup_subsys_state) as the main
      subsys interface handle instead of cgroup and the iterators will be
      updated to use css too.  The iterators need to walk the cgroup
      hierarchy and return the css's matching the origin css, which is a bit
      cumbersome to open code.
      
      This patch converts cgroup_next_sibling() to cgroup_next_child() so
      that it can handle all steps of direct child iteration.  This will be
      used to update iterators to take @css instead of @cgrp.  In addition
      to the new iteration init handling, cgroup_next_child() is
      restructured so that the different branches share the end of iteration
      condition check.
      
      This patch doesn't change any behavior.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Acked-by: NLi Zefan <lizefan@huawei.com>
      3b287a50
    • T
      cgroup: pass around cgroup_subsys_state instead of cgroup in file methods · 182446d0
      Tejun Heo 提交于
      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: NTejun Heo <tj@kernel.org>
      Acked-by: NLi Zefan <lizefan@huawei.com>
      Acked-by: NMichal Hocko <mhocko@suse.cz>
      Acked-by: NVivek Goyal <vgoyal@redhat.com>
      Acked-by: NAristeu Rozanski <aris@redhat.com>
      Acked-by: NDaniel Wagner <daniel.wagner@bmw-carit.de>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Balbir Singh <bsingharora@gmail.com>
      Cc: Matt Helsley <matthltc@us.ibm.com>
      Cc: Jens Axboe <axboe@kernel.dk>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      182446d0
    • T
      cgroup: add cgroup->dummy_css · 67f4c36f
      Tejun Heo 提交于
      cgroup subsystem API is being converted to use css
      (cgroup_subsys_state) as the main handle, which makes things a bit
      awkward for subsystem agnostic core features - the "cgroup.*"
      interface files and various iterations - a bit awkward as they don't
      have a css to use.
      
      This patch adds cgroup->dummy_css which has NULL ->ss and whose only
      role is pointing back to the cgroup.  This will be used to support
      subsystem agnostic features on the coming css based API.
      
      css_parent() is updated to handle dummy_css's.  Note that css will
      soon grow its own ->parent field and css_parent() will be made
      trivial.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Acked-by: NLi Zefan <lizefan@huawei.com>
      67f4c36f
    • T
      cgroup: add subsys backlink pointer to cftype · 2bb566cb
      Tejun Heo 提交于
      cgroup is transitioning to using css (cgroup_subsys_state) instead of
      cgroup as the primary subsystem handle.  The cgroupfs file interface
      will be converted to use css's which requires finding out the
      subsystem from cftype so that the matching css can be determined from
      the cgroup.
      
      This patch adds cftype->ss which points to the subsystem the file
      belongs to.  The field is initialized while a cftype is being
      registered.  This makes it unnecessary to explicitly specify the
      subsystem for other cftype handling functions.  @ss argument dropped
      from various cftype handling functions.
      
      This patch shouldn't introduce any behavior differences.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Acked-by: NLi Zefan <lizefan@huawei.com>
      Acked-by: NVivek Goyal <vgoyal@redhat.com>
      Cc: Jens Axboe <axboe@kernel.dk>
      2bb566cb
    • T
      cgroup: pass around cgroup_subsys_state instead of cgroup in subsystem methods · eb95419b
      Tejun Heo 提交于
      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 da0a12ca ("cgroup: fix a
          leak when percpu_ref_init() fails") is converted too.  Suggested
          by Li Zefan.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Acked-by: NLi Zefan <lizefan@huawei.com>
      Acked-by: NMichal Hocko <mhocko@suse.cz>
      Acked-by: NVivek Goyal <vgoyal@redhat.com>
      Acked-by: NAristeu Rozanski <aris@redhat.com>
      Acked-by: NDaniel Wagner <daniel.wagner@bmw-carit.de>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Balbir Singh <bsingharora@gmail.com>
      Cc: Matt Helsley <matthltc@us.ibm.com>
      Cc: Jens Axboe <axboe@kernel.dk>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      eb95419b
    • T
      cgroup: add css_parent() · 63876986
      Tejun Heo 提交于
      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: NTejun Heo <tj@kernel.org>
      Acked-by: NLi Zefan <lizefan@huawei.com>
      63876986
    • T
      cgroup: add subsystem pointer to cgroup_subsys_state · 72c97e54
      Tejun Heo 提交于
      Currently, given a cgroup_subsys_state, there's no way to find out
      which subsystem the css is for, which we'll need to convert the cgroup
      controller API to primarily use @css instead of @cgroup.  This patch
      adds cgroup_subsys_state->ss which points to the subsystem the @css
      belongs to.
      
      While at it, remove the comment about accessing @css->cgroup to
      determine the hierarchy.  cgroup core will provide API to traverse
      hierarchy of css'es and we don't want subsystems to directly walk
      cgroup hierarchies anymore.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Acked-by: NLi Zefan <lizefan@huawei.com>
      72c97e54
    • T
      cgroup: s/cgroup_subsys_state/cgroup_css/ s/task_subsys_state/task_css/ · 8af01f56
      Tejun Heo 提交于
      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: NTejun Heo <tj@kernel.org>
      Acked-by: NLi Zefan <lizefan@huawei.com>
      8af01f56
  2. 31 7月, 2013 4 次提交
  3. 13 7月, 2013 1 次提交
    • T
      cgroup: replace task_cgroup_path_from_hierarchy() with task_cgroup_path() · 913ffdb5
      Tejun Heo 提交于
      task_cgroup_path_from_hierarchy() was added for the planned new users
      and none of the currently planned users wants to know about multiple
      hierarchies.  This patch drops the multiple hierarchy part and makes
      it always return the path in the first non-dummy hierarchy.
      
      As unified hierarchy will always have id 1, this is guaranteed to
      return the path for the unified hierarchy if mounted; otherwise, it
      will return the path from the hierarchy which happens to occupy the
      lowest hierarchy id, which will usually be the first hierarchy mounted
      after boot.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Acked-by: NLi Zefan <lizefan@huawei.com>
      Cc: Lennart Poettering <lennart@poettering.net>
      Cc: Kay Sievers <kay.sievers@vrfy.org>
      Cc: Jan Kaluža <jkaluza@redhat.com>
      913ffdb5
  4. 11 7月, 2013 3 次提交
    • M
      mm: remove free_area_cache · 98d1e64f
      Michel Lespinasse 提交于
      Since all architectures have been converted to use vm_unmapped_area(),
      there is no remaining use for the free_area_cache.
      Signed-off-by: NMichel Lespinasse <walken@google.com>
      Acked-by: NRik van Riel <riel@redhat.com>
      Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
      Cc: "Luck, Tony" <tony.luck@intel.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: David Howells <dhowells@redhat.com>
      Cc: Helge Deller <deller@gmx.de>
      Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
      Cc: Matt Turner <mattst88@gmail.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Richard Henderson <rth@twiddle.net>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      98d1e64f
    • S
      zbud: add to mm/ · 4e2e2770
      Seth Jennings 提交于
      zbud is an special purpose allocator for storing compressed pages.  It
      is designed to store up to two compressed pages per physical page.
      While this design limits storage density, it has simple and
      deterministic reclaim properties that make it preferable to a higher
      density approach when reclaim will be used.
      
      zbud works by storing compressed pages, or "zpages", together in pairs
      in a single memory page called a "zbud page".  The first buddy is "left
      justifed" at the beginning of the zbud page, and the last buddy is
      "right justified" at the end of the zbud page.  The benefit is that if
      either buddy is freed, the freed buddy space, coalesced with whatever
      slack space that existed between the buddies, results in the largest
      possible free region within the zbud page.
      
      zbud also provides an attractive lower bound on density.  The ratio of
      zpages to zbud pages can not be less than 1.  This ensures that zbud can
      never "do harm" by using more pages to store zpages than the
      uncompressed zpages would have used on their own.
      
      This implementation is a rewrite of the zbud allocator internally used
      by zcache in the driver/staging tree.  The rewrite was necessary to
      remove some of the zcache specific elements that were ingrained
      throughout and provide a generic allocation interface that can later be
      used by zsmalloc and others.
      
      This patch adds zbud to mm/ for later use by zswap.
      Signed-off-by: NSeth Jennings <sjenning@linux.vnet.ibm.com>
      Acked-by: NRik van Riel <riel@redhat.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Nitin Gupta <ngupta@vflare.org>
      Cc: Minchan Kim <minchan@kernel.org>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Dan Magenheimer <dan.magenheimer@oracle.com>
      Cc: Robert Jennings <rcj@linux.vnet.ibm.com>
      Cc: Jenifer Hopper <jhopper@us.ibm.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Johannes Weiner <jweiner@redhat.com>
      Cc: Larry Woodman <lwoodman@redhat.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Dave Hansen <dave@sr71.net>
      Cc: Joe Perches <joe@perches.com>
      Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
      Cc: Cody P Schafer <cody@linux.vnet.ibm.com>
      Cc: Hugh Dickens <hughd@google.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Bob Liu <bob.liu@oracle.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      4e2e2770
    • M
      dm: optimize use SRCU and RCU · 83d5e5b0
      Mikulas Patocka 提交于
      This patch removes "io_lock" and "map_lock" in struct mapped_device and
      "holders" in struct dm_table and replaces these mechanisms with
      sleepable-rcu.
      
      Previously, the code would call "dm_get_live_table" and "dm_table_put" to
      get and release table. Now, the code is changed to call "dm_get_live_table"
      and "dm_put_live_table". dm_get_live_table locks sleepable-rcu and
      dm_put_live_table unlocks it.
      
      dm_get_live_table_fast/dm_put_live_table_fast can be used instead of
      dm_get_live_table/dm_put_live_table. These *_fast functions use
      non-sleepable RCU, so the caller must not block between them.
      
      If the code changes active or inactive dm table, it must call
      dm_sync_table before destroying the old table.
      Signed-off-by: NMikulas Patocka <mpatocka@redhat.com>
      Signed-off-by: NJun'ichi Nomura <j-nomura@ce.jp.nec.com>
      Signed-off-by: NAlasdair G Kergon <agk@redhat.com>
      83d5e5b0
  5. 10 7月, 2013 18 次提交