1. 17 1月, 2020 3 次提交
    • X
      alinux: hotfix: Add Cloud Kernel hotfix enhancement · f94e5b1a
      Xunlei Pang 提交于
      We reserve some fields beforehand for core structures prone to change,
      so that we won't hurt when extra fields have to be added for hotfix,
      thereby inceasing the success rate, we even can hot add features with
      this enhancement.
      
      After reserving, normally cache does not matter as the reserved fields
      (usually at tail) are not accessed at all.
      
      Currently involve the following structures:
          MM:
          struct zone
          struct pglist_data
          struct mm_struct
          struct vm_area_struct
          struct mem_cgroup
          struct writeback_control
      
          Block:
          struct gendisk
          struct backing_dev_info
          struct bio
          struct queue_limits
          struct request_queue
          struct blkcg
          struct blkcg_policy
          struct blk_mq_hw_ctx
          struct blk_mq_tag_set
          struct blk_mq_queue_data
          struct blk_mq_ops
          struct elevator_mq_ops
          struct inode
          struct dentry
          struct address_space
          struct block_device
          struct hd_struct
          struct bio_set
      
          Network:
          struct sk_buff
          struct sock
          struct net_device_ops
          struct xt_target
          struct dst_entry
          struct dst_ops
          struct fib_rule
      
          Scheduler:
          struct task_struct
          struct cfs_rq
          struct rq
          struct sched_statistics
          struct sched_entity
          struct signal_struct
          struct task_group
          struct cpuacct
      
          cgroup:
          struct cgroup_root
          struct cgroup_subsys_state
          struct cgroup_subsys
          struct css_set
      Reviewed-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
      Signed-off-by: NXunlei Pang <xlpang@linux.alibaba.com>
      [ caspar: use SPDX-License-Identifier ]
      Signed-off-by: NCaspar Zhang <caspar@linux.alibaba.com>
      f94e5b1a
    • J
      alinux: introduce psi_v1 boot parameter · dc159a61
      Joseph Qi 提交于
      Instead using static kconfig CONFIG_PSI_CGROUP_V1, we introduce a boot
      parameter psi_v1 to enable psi cgroup v1 support. Default it is
      disabled, which means when passing psi=1 boot parameter, we only support
      cgroup v2.
      This is to keep consistent with other cgroup v1 features such as cgroup
      writeback v1 (cgwb_v1).
      Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
      Acked-by: NXunlei Pang <xlpang@linux.alibaba.com>
      dc159a61
    • X
      alinux: psi: Support PSI under cgroup v1 · 1f49a738
      Xunlei Pang 提交于
      Export "cpu|io|memory.pressure" under cgroup v1 "cpuacct" subsystem.
      Reviewed-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
      Signed-off-by: NXunlei Pang <xlpang@linux.alibaba.com>
      1f49a738
  2. 04 3月, 2018 1 次提交
    • I
      sched/headers: Simplify and clean up header usage in the scheduler · 325ea10c
      Ingo Molnar 提交于
      Do the following cleanups and simplifications:
      
       - sched/sched.h already includes <asm/paravirt.h>, so no need to
         include it in sched/core.c again.
      
       - order the <linux/sched/*.h> headers alphabetically
      
       - add all <linux/sched/*.h> headers to kernel/sched/sched.h
      
       - remove all unnecessary includes from the .c files that
         are already included in kernel/sched/sched.h.
      
      Finally, make all scheduler .c files use a single common header:
      
        #include "sched.h"
      
      ... which now contains a union of the relied upon headers.
      
      This makes the various .c files easier to read and easier to handle.
      
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: linux-kernel@vger.kernel.org
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      325ea10c
  3. 03 3月, 2018 1 次提交
    • I
      sched: Clean up and harmonize the coding style of the scheduler code base · 97fb7a0a
      Ingo Molnar 提交于
      A good number of small style inconsistencies have accumulated
      in the scheduler core, so do a pass over them to harmonize
      all these details:
      
       - fix speling in comments,
      
       - use curly braces for multi-line statements,
      
       - remove unnecessary parentheses from integer literals,
      
       - capitalize consistently,
      
       - remove stray newlines,
      
       - add comments where necessary,
      
       - remove invalid/unnecessary comments,
      
       - align structure definitions and other data types vertically,
      
       - add missing newlines for increased readability,
      
       - fix vertical tabulation where it's misaligned,
      
       - harmonize preprocessor conditional block labeling
         and vertical alignment,
      
       - remove line-breaks where they uglify the code,
      
       - add newline after local variable definitions,
      
      No change in functionality:
      
        md5:
           1191fa0a890cfa8132156d2959d7e9e2  built-in.o.before.asm
           1191fa0a890cfa8132156d2959d7e9e2  built-in.o.after.asm
      
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: linux-kernel@vger.kernel.org
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      97fb7a0a
  4. 02 11月, 2017 1 次提交
    • G
      License cleanup: add SPDX GPL-2.0 license identifier to files with no license · b2441318
      Greg Kroah-Hartman 提交于
      Many source files in the tree are missing licensing information, which
      makes it harder for compliance tools to determine the correct license.
      
      By default all files without license information are under the default
      license of the kernel, which is GPL version 2.
      
      Update the files which contain no license information with the 'GPL-2.0'
      SPDX license identifier.  The SPDX identifier is a legally binding
      shorthand, which can be used instead of the full boiler plate text.
      
      This patch is based on work done by Thomas Gleixner and Kate Stewart and
      Philippe Ombredanne.
      
      How this work was done:
      
      Patches were generated and checked against linux-4.14-rc6 for a subset of
      the use cases:
       - file had no licensing information it it.
       - file was a */uapi/* one with no licensing information in it,
       - file was a */uapi/* one with existing licensing information,
      
      Further patches will be generated in subsequent months to fix up cases
      where non-standard license headers were used, and references to license
      had to be inferred by heuristics based on keywords.
      
      The analysis to determine which SPDX License Identifier to be applied to
      a file was done in a spreadsheet of side by side results from of the
      output of two independent scanners (ScanCode & Windriver) producing SPDX
      tag:value files created by Philippe Ombredanne.  Philippe prepared the
      base worksheet, and did an initial spot review of a few 1000 files.
      
      The 4.13 kernel was the starting point of the analysis with 60,537 files
      assessed.  Kate Stewart did a file by file comparison of the scanner
      results in the spreadsheet to determine which SPDX license identifier(s)
      to be applied to the file. She confirmed any determination that was not
      immediately clear with lawyers working with the Linux Foundation.
      
      Criteria used to select files for SPDX license identifier tagging was:
       - Files considered eligible had to be source code files.
       - Make and config files were included as candidates if they contained >5
         lines of source
       - File already had some variant of a license header in it (even if <5
         lines).
      
      All documentation files were explicitly excluded.
      
      The following heuristics were used to determine which SPDX license
      identifiers to apply.
      
       - when both scanners couldn't find any license traces, file was
         considered to have no license information in it, and the top level
         COPYING file license applied.
      
         For non */uapi/* files that summary was:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|-------
         GPL-2.0                                              11139
      
         and resulted in the first patch in this series.
      
         If that file was a */uapi/* path one, it was "GPL-2.0 WITH
         Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|-------
         GPL-2.0 WITH Linux-syscall-note                        930
      
         and resulted in the second patch in this series.
      
       - if a file had some form of licensing information in it, and was one
         of the */uapi/* ones, it was denoted with the Linux-syscall-note if
         any GPL family license was found in the file or had no licensing in
         it (per prior point).  Results summary:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|------
         GPL-2.0 WITH Linux-syscall-note                       270
         GPL-2.0+ WITH Linux-syscall-note                      169
         ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
         ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
         LGPL-2.1+ WITH Linux-syscall-note                      15
         GPL-1.0+ WITH Linux-syscall-note                       14
         ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
         LGPL-2.0+ WITH Linux-syscall-note                       4
         LGPL-2.1 WITH Linux-syscall-note                        3
         ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
         ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1
      
         and that resulted in the third patch in this series.
      
       - when the two scanners agreed on the detected license(s), that became
         the concluded license(s).
      
       - when there was disagreement between the two scanners (one detected a
         license but the other didn't, or they both detected different
         licenses) a manual inspection of the file occurred.
      
       - In most cases a manual inspection of the information in the file
         resulted in a clear resolution of the license that should apply (and
         which scanner probably needed to revisit its heuristics).
      
       - When it was not immediately clear, the license identifier was
         confirmed with lawyers working with the Linux Foundation.
      
       - If there was any question as to the appropriate license identifier,
         the file was flagged for further research and to be revisited later
         in time.
      
      In total, over 70 hours of logged manual review was done on the
      spreadsheet to determine the SPDX license identifiers to apply to the
      source files by Kate, Philippe, Thomas and, in some cases, confirmation
      by lawyers working with the Linux Foundation.
      
      Kate also obtained a third independent scan of the 4.13 code base from
      FOSSology, and compared selected files where the other two scanners
      disagreed against that SPDX file, to see if there was new insights.  The
      Windriver scanner is based on an older version of FOSSology in part, so
      they are related.
      
      Thomas did random spot checks in about 500 files from the spreadsheets
      for the uapi headers and agreed with SPDX license identifier in the
      files he inspected. For the non-uapi files Thomas did random spot checks
      in about 15000 files.
      
      In initial set of patches against 4.14-rc6, 3 files were found to have
      copy/paste license identifier errors, and have been fixed to reflect the
      correct identifier.
      
      Additionally Philippe spent 10 hours this week doing a detailed manual
      inspection and review of the 12,461 patched files from the initial patch
      version early this week with:
       - a full scancode scan run, collecting the matched texts, detected
         license ids and scores
       - reviewing anything where there was a license detected (about 500+
         files) to ensure that the applied SPDX license was correct
       - reviewing anything where there was no detection but the patch license
         was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
         SPDX license was correct
      
      This produced a worksheet with 20 files needing minor correction.  This
      worksheet was then exported into 3 different .csv files for the
      different types of files to be modified.
      
      These .csv files were then reviewed by Greg.  Thomas wrote a script to
      parse the csv files and add the proper SPDX tag to the file, in the
      format that the file expected.  This script was further refined by Greg
      based on the output to detect more types of files automatically and to
      distinguish between header and source .c files (which need different
      comment types.)  Finally Greg ran the script using the .csv files to
      generate the patches.
      Reviewed-by: NKate Stewart <kstewart@linuxfoundation.org>
      Reviewed-by: NPhilippe Ombredanne <pombredanne@nexb.com>
      Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b2441318
  5. 01 2月, 2017 1 次提交
    • F
      sched/cputime: Convert kcpustat to nsecs · 7fb1327e
      Frederic Weisbecker 提交于
      Kernel CPU stats are stored in cputime_t which is an architecture
      defined type, and hence a bit opaque and requiring accessors and mutators
      for any operation.
      
      Converting them to nsecs simplifies the code and is one step toward
      the removal of cputime_t in the core code.
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Stanislaw Gruszka <sgruszka@redhat.com>
      Cc: Wanpeng Li <wanpeng.li@hotmail.com>
      Link: http://lkml.kernel.org/r/1485832191-26889-4-git-send-email-fweisbec@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      7fb1327e
  6. 16 11月, 2016 1 次提交
  7. 09 7月, 2016 3 次提交
  8. 13 4月, 2016 1 次提交
  9. 31 3月, 2016 2 次提交
  10. 21 3月, 2016 2 次提交
  11. 23 2月, 2016 1 次提交
  12. 15 7月, 2014 1 次提交
    • T
      cgroup: rename cgroup_subsys->base_cftypes to ->legacy_cftypes · 5577964e
      Tejun Heo 提交于
      Currently, cgroup_subsys->base_cftypes is used for both the unified
      default hierarchy and legacy ones and subsystems can mark each file
      with either CFTYPE_ONLY_ON_DFL or CFTYPE_INSANE if it has to appear
      only on one of them.  This is quite hairy and error-prone.  Also, we
      may end up exposing interface files to the default hierarchy without
      thinking it through.
      
      cgroup_subsys will grow two separate cftype arrays and apply each only
      on the hierarchies of the matching type.  This will allow organizing
      cftypes in a lot clearer way and encourage subsystems to scrutinize
      the interface which is being exposed in the new default hierarchy.
      
      In preparation, this patch renames cgroup_subsys->base_cftypes to
      cgroup_subsys->legacy_cftypes.  This patch is pure rename.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Acked-by: NNeil Horman <nhorman@tuxdriver.com>
      Acked-by: NLi Zefan <lizefan@huawei.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Vivek Goyal <vgoyal@redhat.com>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
      Cc: Aristeu Rozanski <aris@redhat.com>
      Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
      5577964e
  13. 17 5月, 2014 1 次提交
    • T
      cgroup: remove css_parent() · 5c9d535b
      Tejun Heo 提交于
      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: NTejun Heo <tj@kernel.org>
      Acked-by: NMichal Hocko <mhocko@suse.cz>
      Acked-by: NNeil Horman <nhorman@tuxdriver.com>
      Acked-by: N"David S. Miller" <davem@davemloft.net>
      Acked-by: NLi Zefan <lizefan@huawei.com>
      Cc: Vivek Goyal <vgoyal@redhat.com>
      Cc: Jens Axboe <axboe@kernel.dk>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      5c9d535b
  14. 08 2月, 2014 1 次提交
    • T
      cgroup: clean up cgroup_subsys names and initialization · 073219e9
      Tejun Heo 提交于
      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 fe1217c4 ("net: net_cls: move cgroupfs
          classid handling into core").
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Acked-by: NNeil Horman <nhorman@tuxdriver.com>
      Acked-by: N"David S. Miller" <davem@davemloft.net>
      Acked-by: N"Rafael J. Wysocki" <rjw@rjwysocki.net>
      Acked-by: NMichal Hocko <mhocko@suse.cz>
      Acked-by: NPeter Zijlstra <peterz@infradead.org>
      Acked-by: NAristeu Rozanski <aris@redhat.com>
      Acked-by: NIngo Molnar <mingo@redhat.com>
      Acked-by: NLi Zefan <lizefan@huawei.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Balbir Singh <bsingharora@gmail.com>
      Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: Serge E. Hallyn <serue@us.ibm.com>
      Cc: Vivek Goyal <vgoyal@redhat.com>
      Cc: Thomas Graf <tgraf@suug.ch>
      073219e9
  15. 06 12月, 2013 2 次提交
    • T
      cgroup: replace cftype->read_seq_string() with cftype->seq_show() · 2da8ca82
      Tejun Heo 提交于
      In preparation of conversion to kernfs, cgroup file handling is
      updated so that it can be easily mapped to kernfs.  This patch
      replaces cftype->read_seq_string() with cftype->seq_show() which is
      not limited to single_open() operation and will map directcly to
      kernfs seq_file interface.
      
      The conversions are mechanical.  As ->seq_show() doesn't have @css and
      @cft, the functions which make use of them are converted to use
      seq_css() and seq_cft() respectively.  In several occassions, e.f. if
      it has seq_string in its name, the function name is updated to fit the
      new method better.
      
      This patch does not introduce any behavior changes.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Acked-by: NAristeu Rozanski <arozansk@redhat.com>
      Acked-by: NVivek Goyal <vgoyal@redhat.com>
      Acked-by: NMichal Hocko <mhocko@suse.cz>
      Acked-by: NDaniel Wagner <daniel.wagner@bmw-carit.de>
      Acked-by: NLi Zefan <lizefan@huawei.com>
      Cc: Jens Axboe <axboe@kernel.dk>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Balbir Singh <bsingharora@gmail.com>
      Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: Neil Horman <nhorman@tuxdriver.com>
      2da8ca82
    • T
      cgroup, sched: convert away from cftype->read_map() · 44ffc75b
      Tejun Heo 提交于
      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.
      
      cftype->read_map() doesn't add any value and being replaced with
      ->read_seq_string().  Update cpu_stats_show() and cpuacct_stats_show()
      accordingly.
      
      This patch doesn't make any visible behavior changes.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Acked-by: NLi Zefan <lizefan@huawei.com>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      44ffc75b
  16. 09 8月, 2013 5 次提交
    • 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: 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/update accessors which obtain subsys specific data from css · a7c6d554
      Tejun Heo 提交于
      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: NTejun Heo <tj@kernel.org>
      Acked-by: NLi Zefan <lizefan@huawei.com>
      a7c6d554
    • 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
  17. 10 4月, 2013 11 次提交