1. 02 Nov, 2017 1 commit
    • Greg Kroah-Hartman's avatar
      License cleanup: add SPDX GPL-2.0 license identifier to files with no license · b2441318
      Greg Kroah-Hartman authored
      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: default avatarKate Stewart <kstewart@linuxfoundation.org>
      Reviewed-by: default avatarPhilippe Ombredanne <pombredanne@nexb.com>
      Reviewed-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b2441318
  2. 17 Aug, 2017 1 commit
    • Mathieu Desnoyers's avatar
      membarrier: Provide expedited private command · 22e4ebb9
      Mathieu Desnoyers authored
      Implement MEMBARRIER_CMD_PRIVATE_EXPEDITED with IPIs using cpumask built
      from all runqueues for which current thread's mm is the same as the
      thread calling sys_membarrier. It executes faster than the non-expedited
      variant (no blocking). It also works on NOHZ_FULL configurations.
      
      Scheduler-wise, it requires a memory barrier before and after context
      switching between processes (which have different mm). The memory
      barrier before context switch is already present. For the barrier after
      context switch:
      
      * Our TSO archs can do RELEASE without being a full barrier. Look at
        x86 spin_unlock() being a regular STORE for example.  But for those
        archs, all atomics imply smp_mb and all of them have atomic ops in
        switch_mm() for mm_cpumask(), and on x86 the CR3 load acts as a full
        barrier.
      
      * From all weakly ordered machines, only ARM64 and PPC can do RELEASE,
        the rest does indeed do smp_mb(), so there the spin_unlock() is a full
        barrier and we're good.
      
      * ARM64 has a very heavy barrier in switch_to(), which suffices.
      
      * PPC just removed its barrier from switch_to(), but appears to be
        talking about adding something to switch_mm(). So add a
        smp_mb__after_unlock_lock() for now, until this is settled on the PPC
        side.
      
      Changes since v3:
      - Properly document the memory barriers provided by each architecture.
      
      Changes since v2:
      - Address comments from Peter Zijlstra,
      - Add smp_mb__after_unlock_lock() after finish_lock_switch() in
        finish_task_switch() to add the memory barrier we need after storing
        to rq->curr. This is much simpler than the previous approach relying
        on atomic_dec_and_test() in mmdrop(), which actually added a memory
        barrier in the common case of switching between userspace processes.
      - Return -EINVAL when MEMBARRIER_CMD_SHARED is used on a nohz_full
        kernel, rather than having the whole membarrier system call returning
        -ENOSYS. Indeed, CMD_PRIVATE_EXPEDITED is compatible with nohz_full.
        Adapt the CMD_QUERY mask accordingly.
      
      Changes since v1:
      - move membarrier code under kernel/sched/ because it uses the
        scheduler runqueue,
      - only add the barrier when we switch from a kernel thread. The case
        where we switch from a user-space thread is already handled by
        the atomic_dec_and_test() in mmdrop().
      - add a comment to mmdrop() documenting the requirement on the implicit
        memory barrier.
      
      CC: Peter Zijlstra <peterz@infradead.org>
      CC: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
      CC: Boqun Feng <boqun.feng@gmail.com>
      CC: Andrew Hunter <ahh@google.com>
      CC: Maged Michael <maged.michael@gmail.com>
      CC: gromer@google.com
      CC: Avi Kivity <avi@scylladb.com>
      CC: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      CC: Paul Mackerras <paulus@samba.org>
      CC: Michael Ellerman <mpe@ellerman.id.au>
      Signed-off-by: default avatarMathieu Desnoyers <mathieu.desnoyers@efficios.com>
      Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      Tested-by: default avatarDave Watson <davejwatson@fb.com>
      22e4ebb9
  3. 20 Jun, 2017 1 commit
    • Ingo Molnar's avatar
      sched/wait: Split out the wait_bit*() APIs from <linux/wait.h> into <linux/wait_bit.h> · 5dd43ce2
      Ingo Molnar authored
      The wait_bit*() types and APIs are mixed into wait.h, but they
      are a pretty orthogonal extension of wait-queues.
      
      Furthermore, only about 50 kernel files use these APIs, while
      over 1000 use the regular wait-queue functionality.
      
      So clean up the main wait.h by moving the wait-bit functionality
      out of it, into a separate .h and .c file:
      
        include/linux/wait_bit.h  for types and APIs
        kernel/sched/wait_bit.c   for the implementation
      
      Update all header dependencies.
      
      This reduces the size of wait.h rather significantly, by about 30%.
      
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: linux-kernel@vger.kernel.org
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      5dd43ce2
  4. 08 Jun, 2017 1 commit
  5. 08 Feb, 2017 1 commit
    • Ingo Molnar's avatar
      sched/autogroup: Rename auto_group.[ch] to autogroup.[ch] · 1051408f
      Ingo Molnar authored
      The names are all 'autogroup', not 'auto_group' - so rename
      the kernel/sched/auto_group.[ch] to match the existing
      nomenclature.
      
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: linux-kernel@vger.kernel.org
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      1051408f
  6. 07 Feb, 2017 1 commit
  7. 01 Apr, 2016 1 commit
    • Rafael J. Wysocki's avatar
      cpufreq: schedutil: New governor based on scheduler utilization data · 9bdcb44e
      Rafael J. Wysocki authored
      Add a new cpufreq scaling governor, called "schedutil", that uses
      scheduler-provided CPU utilization information as input for making
      its decisions.
      
      Doing that is possible after commit 34e2c555 (cpufreq: Add
      mechanism for registering utilization update callbacks) that
      introduced cpufreq_update_util() called by the scheduler on
      utilization changes (from CFS) and RT/DL task status updates.
      In particular, CPU frequency scaling decisions may be based on
      the the utilization data passed to cpufreq_update_util() by CFS.
      
      The new governor is relatively simple.
      
      The frequency selection formula used by it depends on whether or not
      the utilization is frequency-invariant.  In the frequency-invariant
      case the new CPU frequency is given by
      
      	next_freq = 1.25 * max_freq * util / max
      
      where util and max are the last two arguments of cpufreq_update_util().
      In turn, if util is not frequency-invariant, the maximum frequency in
      the above formula is replaced with the current frequency of the CPU:
      
      	next_freq = 1.25 * curr_freq * util / max
      
      The coefficient 1.25 corresponds to the frequency tipping point at
      (util / max) = 0.8.
      
      All of the computations are carried out in the utilization update
      handlers provided by the new governor.  One of those handlers is
      used for cpufreq policies shared between multiple CPUs and the other
      one is for policies with one CPU only (and therefore it doesn't need
      to use any extra synchronization means).
      
      The governor supports fast frequency switching if that is supported
      by the cpufreq driver in use and possible for the given policy.
      In the fast switching case, all operations of the governor take
      place in its utilization update handlers.  If fast switching cannot
      be used, the frequency switch operations are carried out with the
      help of a work item which only calls __cpufreq_driver_target()
      (under a mutex) to trigger a frequency update (to a value already
      computed beforehand in one of the utilization update handlers).
      
      Currently, the governor treats all of the RT and DL tasks as
      "unknown utilization" and sets the frequency to the allowed
      maximum when updated from the RT or DL sched classes.  That
      heavy-handed approach should be replaced with something more
      subtle and specifically targeted at RT and DL tasks.
      
      The governor shares some tunables management code with the
      "ondemand" and "conservative" governors and uses some common
      definitions from cpufreq_governor.h, but apart from that it
      is stand-alone.
      Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
      Acked-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
      Acked-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      9bdcb44e
  8. 22 Mar, 2016 1 commit
    • Dmitry Vyukov's avatar
      kernel: add kcov code coverage · 5c9a8750
      Dmitry Vyukov authored
      kcov provides code coverage collection for coverage-guided fuzzing
      (randomized testing).  Coverage-guided fuzzing is a testing technique
      that uses coverage feedback to determine new interesting inputs to a
      system.  A notable user-space example is AFL
      (http://lcamtuf.coredump.cx/afl/).  However, this technique is not
      widely used for kernel testing due to missing compiler and kernel
      support.
      
      kcov does not aim to collect as much coverage as possible.  It aims to
      collect more or less stable coverage that is function of syscall inputs.
      To achieve this goal it does not collect coverage in soft/hard
      interrupts and instrumentation of some inherently non-deterministic or
      non-interesting parts of kernel is disbled (e.g.  scheduler, locking).
      
      Currently there is a single coverage collection mode (tracing), but the
      API anticipates additional collection modes.  Initially I also
      implemented a second mode which exposes coverage in a fixed-size hash
      table of counters (what Quentin used in his original patch).  I've
      dropped the second mode for simplicity.
      
      This patch adds the necessary support on kernel side.  The complimentary
      compiler support was added in gcc revision 231296.
      
      We've used this support to build syzkaller system call fuzzer, which has
      found 90 kernel bugs in just 2 months:
      
        https://github.com/google/syzkaller/wiki/Found-Bugs
      
      We've also found 30+ bugs in our internal systems with syzkaller.
      Another (yet unexplored) direction where kcov coverage would greatly
      help is more traditional "blob mutation".  For example, mounting a
      random blob as a filesystem, or receiving a random blob over wire.
      
      Why not gcov.  Typical fuzzing loop looks as follows: (1) reset
      coverage, (2) execute a bit of code, (3) collect coverage, repeat.  A
      typical coverage can be just a dozen of basic blocks (e.g.  an invalid
      input).  In such context gcov becomes prohibitively expensive as
      reset/collect coverage steps depend on total number of basic
      blocks/edges in program (in case of kernel it is about 2M).  Cost of
      kcov depends only on number of executed basic blocks/edges.  On top of
      that, kernel requires per-thread coverage because there are always
      background threads and unrelated processes that also produce coverage.
      With inlined gcov instrumentation per-thread coverage is not possible.
      
      kcov exposes kernel PCs and control flow to user-space which is
      insecure.  But debugfs should not be mapped as user accessible.
      
      Based on a patch by Quentin Casasnovas.
      
      [akpm@linux-foundation.org: make task_struct.kcov_mode have type `enum kcov_mode']
      [akpm@linux-foundation.org: unbreak allmodconfig]
      [akpm@linux-foundation.org: follow x86 Makefile layout standards]
      Signed-off-by: default avatarDmitry Vyukov <dvyukov@google.com>
      Reviewed-by: default avatarKees Cook <keescook@chromium.org>
      Cc: syzkaller <syzkaller@googlegroups.com>
      Cc: Vegard Nossum <vegard.nossum@oracle.com>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Tavis Ormandy <taviso@google.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
      Cc: Kostya Serebryany <kcc@google.com>
      Cc: Eric Dumazet <edumazet@google.com>
      Cc: Alexander Potapenko <glider@google.com>
      Cc: Kees Cook <keescook@google.com>
      Cc: Bjorn Helgaas <bhelgaas@google.com>
      Cc: Sasha Levin <sasha.levin@oracle.com>
      Cc: David Drysdale <drysdale@google.com>
      Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
      Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
      Cc: Kirill A. Shutemov <kirill@shutemov.name>
      Cc: Jiri Slaby <jslaby@suse.cz>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      5c9a8750
  9. 10 Mar, 2016 1 commit
  10. 25 Feb, 2016 1 commit
    • Peter Zijlstra (Intel)'s avatar
      wait.[ch]: Introduce the simple waitqueue (swait) implementation · 13b35686
      Peter Zijlstra (Intel) authored
      The existing wait queue support has support for custom wake up call
      backs, wake flags, wake key (passed to call back) and exclusive
      flags that allow wakers to be tagged as exclusive, for limiting
      the number of wakers.
      
      In a lot of cases, none of these features are used, and hence we
      can benefit from a slimmed down version that lowers memory overhead
      and reduces runtime overhead.
      
      The concept originated from -rt, where waitqueues are a constant
      source of trouble, as we can't convert the head lock to a raw
      spinlock due to fancy and long lasting callbacks.
      
      With the removal of custom callbacks, we can use a raw lock for
      queue list manipulations, hence allowing the simple wait support
      to be used in -rt.
      
      [Patch is from PeterZ which is based on Thomas version. Commit message is
       written by Paul G.
       Daniel:  - Fixed some compile issues
       	  - Added non-lazy implementation of swake_up_locked as suggested
      	     by Boqun Feng.]
      Originally-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: default avatarDaniel Wagner <daniel.wagner@bmw-carit.de>
      Acked-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: linux-rt-users@vger.kernel.org
      Cc: Boqun Feng <boqun.feng@gmail.com>
      Cc: Marcelo Tosatti <mtosatti@redhat.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
      Link: http://lkml.kernel.org/r/1455871601-27484-2-git-send-email-wagi@monom.orgSigned-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      13b35686
  11. 08 May, 2015 1 commit
    • Peter Zijlstra's avatar
      sched: Move the loadavg code to a more obvious location · 3289bdb4
      Peter Zijlstra authored
      I could not find the loadavg code.. turns out it was hidden in a file
      called proc.c. It further got mingled up with the cruft per rq load
      indexes (which we really want to get rid of).
      
      Move the per rq load indexes into the fair.c load-balance code (that's
      the only thing that uses them) and rename proc.c to loadavg.c so we
      can find it again.
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      [ Did minor cleanups to the code. ]
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      3289bdb4
  12. 29 Jan, 2015 1 commit
  13. 11 Feb, 2014 1 commit
  14. 13 Jan, 2014 2 commits
    • Juri Lelli's avatar
      sched/deadline: speed up SCHED_DEADLINE pushes with a push-heap · 6bfd6d72
      Juri Lelli authored
      Data from tests confirmed that the original active load balancing
      logic didn't scale neither in the number of CPU nor in the number of
      tasks (as sched_rt does).
      
      Here we provide a global data structure to keep track of deadlines
      of the running tasks in the system. The structure is composed by
      a bitmask showing the free CPUs and a max-heap, needed when the system
      is heavily loaded.
      
      The implementation and concurrent access scheme are kept simple by
      design. However, our measurements show that we can compete with sched_rt
      on large multi-CPUs machines [1].
      
      Only the push path is addressed, the extension to use this structure
      also for pull decisions is straightforward. However, we are currently
      evaluating different (in order to decrease/avoid contention) data
      structures to solve possibly both problems. We are also going to re-run
      tests considering recent changes inside cpupri [2].
      
       [1] http://retis.sssup.it/~jlelli/papers/Ospert11Lelli.pdf
       [2] http://www.spinics.net/lists/linux-rt-users/msg06778.htmlSigned-off-by: default avatarJuri Lelli <juri.lelli@gmail.com>
      Signed-off-by: default avatarPeter Zijlstra <peterz@infradead.org>
      Link: http://lkml.kernel.org/r/1383831828-15501-14-git-send-email-juri.lelli@gmail.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      6bfd6d72
    • Dario Faggioli's avatar
      sched/deadline: Add SCHED_DEADLINE structures & implementation · aab03e05
      Dario Faggioli authored
      Introduces the data structures, constants and symbols needed for
      SCHED_DEADLINE implementation.
      
      Core data structure of SCHED_DEADLINE are defined, along with their
      initializers. Hooks for checking if a task belong to the new policy
      are also added where they are needed.
      
      Adds a scheduling class, in sched/dl.c and a new policy called
      SCHED_DEADLINE. It is an implementation of the Earliest Deadline
      First (EDF) scheduling algorithm, augmented with a mechanism (called
      Constant Bandwidth Server, CBS) that makes it possible to isolate
      the behaviour of tasks between each other.
      
      The typical -deadline task will be made up of a computation phase
      (instance) which is activated on a periodic or sporadic fashion. The
      expected (maximum) duration of such computation is called the task's
      runtime; the time interval by which each instance need to be completed
      is called the task's relative deadline. The task's absolute deadline
      is dynamically calculated as the time instant a task (better, an
      instance) activates plus the relative deadline.
      
      The EDF algorithms selects the task with the smallest absolute
      deadline as the one to be executed first, while the CBS ensures each
      task to run for at most its runtime every (relative) deadline
      length time interval, avoiding any interference between different
      tasks (bandwidth isolation).
      Thanks to this feature, also tasks that do not strictly comply with
      the computational model sketched above can effectively use the new
      policy.
      
      To summarize, this patch:
       - introduces the data structures, constants and symbols needed;
       - implements the core logic of the scheduling algorithm in the new
         scheduling class file;
       - provides all the glue code between the new scheduling class and
         the core scheduler and refines the interactions between sched/dl
         and the other existing scheduling classes.
      Signed-off-by: default avatarDario Faggioli <raistlin@linux.it>
      Signed-off-by: default avatarMichael Trimarchi <michael@amarulasolutions.com>
      Signed-off-by: default avatarFabio Checconi <fchecconi@gmail.com>
      Signed-off-by: default avatarJuri Lelli <juri.lelli@gmail.com>
      Signed-off-by: default avatarPeter Zijlstra <peterz@infradead.org>
      Link: http://lkml.kernel.org/r/1383831828-15501-4-git-send-email-juri.lelli@gmail.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      aab03e05
  15. 06 Nov, 2013 2 commits
  16. 07 May, 2013 1 commit
  17. 10 Apr, 2013 1 commit
  18. 20 Aug, 2012 1 commit
    • Frederic Weisbecker's avatar
      sched: Move cputime code to its own file · 73fbec60
      Frederic Weisbecker authored
      Extract cputime code from the giant sched/core.c and
      put it in its own file. This make it easier to deal with
      this particular area and de-bloat a bit more core.c
      Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      Acked-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Peter Zijlstra <peterz@infradead.org>
      73fbec60
  19. 05 May, 2012 1 commit
    • Thomas Gleixner's avatar
      init_task: Create generic init_task instance · a4a2eb49
      Thomas Gleixner authored
      All archs define init_task in the same way (except ia64, but there is
      no particular reason why ia64 cannot use the common version). Create a
      generic instance so all archs can be converted over.
      
      The config switch is temporary and will be removed when all archs are
      converted over.
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Chen Liqin <liqin.chen@sunplusct.com>
      Cc: Chris Metcalf <cmetcalf@tilera.com>
      Cc: Chris Zankel <chris@zankel.net>
      Cc: David Howells <dhowells@redhat.com>
      Cc: David S. Miller <davem@davemloft.net>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
      Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
      Cc: Hirokazu Takata <takata@linux-m32r.org>
      Cc: James E.J. Bottomley <jejb@parisc-linux.org>
      Cc: Jesper Nilsson <jesper.nilsson@axis.com>
      Cc: Jonas Bonn <jonas@southpole.se>
      Cc: Mark Salter <msalter@redhat.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Matt Turner <mattst88@gmail.com>
      Cc: Michal Simek <monstr@monstr.eu>
      Cc: Mike Frysinger <vapier@gentoo.org>
      Cc: Paul Mundt <lethal@linux-sh.org>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Richard Kuo <rkuo@codeaurora.org>
      Cc: Richard Weinberger <richard@nod.at>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Link: http://lkml.kernel.org/r/20120503085034.092585287@linutronix.de
      a4a2eb49
  20. 17 Nov, 2011 1 commit