Eric Lee / smarc-fsl-linux-kernel

14 Mar, 2010

1 commit

11 Mar, 2010

1 commit

07 Mar, 2010

1 commit

  • 78d7d407b   kernel core: use helpers for rlimits ... Browse Code »

    Make sure compiler won't do weird things with limits. E.g. fetching them
    twice may return 2 different values after writable limits are implemented.

    I.e. either use rlimit helpers added in commit 3e10e716abf3 ("resource:
    add helpers for fetching rlimits") or ACCESS_ONCE if not applicable.

    Signed-off-by: Jiri Slaby
    Cc: Ingo Molnar
    Cc: Peter Zijlstra
    Cc: Thomas Gleixner
    Cc: john stultz
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Jiri Slaby
     

04 Feb, 2010

1 commit

23 Jan, 2010

2 commits

  • 37dad3fce   sched: Implement head queueing for sched_rt ... Browse Code »

    The ability of enqueueing a task to the head of a SCHED_FIFO priority
    list is required to fix some violations of POSIX scheduling policy.

    Implement the functionality in sched_rt.

    Signed-off-by: Thomas Gleixner
    Acked-by: Peter Zijlstra
    Tested-by: Carsten Emde
    Tested-by: Mathias Weber
    LKML-Reference:

    Thomas Gleixner
     
  • ea87bb785   sched: Extend enqueue_task to allow head queueing ... Browse Code »

    The ability of enqueueing a task to the head of a SCHED_FIFO priority
    list is required to fix some violations of POSIX scheduling policy.

    Extend the related functions with a "head" argument.

    Signed-off-by: Thomas Gleixner
    Acked-by: Peter Zijlstra
    Tested-by: Carsten Emde
    Tested-by: Mathias Weber
    LKML-Reference:

    Thomas Gleixner
     

21 Jan, 2010

1 commit

17 Jan, 2010

1 commit

  • 6d686f456   sched: Don't expose local functions ... Browse Code »

    kernel/sched: don't expose local functions

    The get_rr_interval_* functions are all class methods of
    struct sched_class. They are not exported so make them
    static.

    Signed-off-by: H Hartley Sweeten
    Cc: Peter Zijlstra
    LKML-Reference:
    Signed-off-by: Ingo Molnar

    H Hartley Sweeten
     

17 Dec, 2009

1 commit

  • efbbd05a5   sched: Add pre and post wakeup hooks ... Browse Code »

    As will be apparent in the next patch, we need a pre wakeup hook
    for sched_fair task migration, hence rename the post wakeup hook
    and one pre wakeup.

    Signed-off-by: Peter Zijlstra
    Cc: Mike Galbraith
    LKML-Reference:
    Signed-off-by: Ingo Molnar

    Peter Zijlstra
     

15 Dec, 2009

2 commits

09 Dec, 2009

1 commit

  • dba091b9e   sched: Protect sched_rr_get_param() access to task->sched_class ... Browse Code »

    sched_rr_get_param calls
    task->sched_class->get_rr_interval(task) without protection
    against a concurrent sched_setscheduler() call which modifies
    task->sched_class.

    Serialize the access with task_rq_lock(task) and hand the rq
    pointer into get_rr_interval() as it's needed at least in the
    sched_fair implementation.

    Signed-off-by: Thomas Gleixner
    Acked-by: Peter Zijlstra
    LKML-Reference:
    Signed-off-by: Ingo Molnar

    Thomas Gleixner
     

04 Nov, 2009

1 commit

  • e2c880630   cpumask: Simplify sched_rt.c ... Browse Code »

    find_lowest_rq() wants to call pick_optimal_cpu() on the
    intersection of sched_domain_span(sd) and lowest_mask. Rather
    than doing a cpus_and into a temporary, we can open-code it.

    This actually makes the code slightly clearer, IMHO.

    Signed-off-by: Rusty Russell
    Acked-by: Gregory Haskins
    Cc: Steven Rostedt
    LKML-Reference:
    Signed-off-by: Ingo Molnar

    Rusty Russell
     

21 Sep, 2009

1 commit

15 Sep, 2009

3 commits

04 Sep, 2009

1 commit

  • e9e9250bc   sched: Scale down cpu_power due to RT tasks ... Browse Code »

    Keep an average on the amount of time spend on RT tasks and use
    that fraction to scale down the cpu_power for regular tasks.

    Signed-off-by: Peter Zijlstra
    Tested-by: Andreas Herrmann
    Acked-by: Andreas Herrmann
    Acked-by: Gautham R Shenoy
    Cc: Balbir Singh
    LKML-Reference:
    Signed-off-by: Ingo Molnar

    Peter Zijlstra
     

02 Aug, 2009

4 commits

  • bcf08df3b   sched: Fix cpupri build on !CONFIG_SMP ... Browse Code »

    This build bug:

    In file included from kernel/sched.c:1765:
    kernel/sched_rt.c: In function ‘has_pushable_tasks’:
    kernel/sched_rt.c:1069: error: ‘struct rt_rq’ has no member named ‘pushable_tasks’
    kernel/sched_rt.c: In function ‘pick_next_task_rt’:
    kernel/sched_rt.c:1084: error: ‘struct rq’ has no member named ‘post_schedule’

    Triggers because both pushable_tasks and post_schedule are
    SMP-only fields.

    Move pushable_tasks() to the SMP section and #ifdef the post_schedule use.

    Cc: Gregory Haskins
    Cc: Peter Zijlstra
    LKML-Reference:
    Signed-off-by: Ingo Molnar

    Ingo Molnar
     
  • 8f48894fc   sched: Add debug check to task_of() ... Browse Code »

    A frequent mistake appears to be to call task_of() on a
    scheduler entity that is not actually a task, which can result
    in a wild pointer.

    Add a check to catch these mistakes.

    Suggested-by: Ingo Molnar
    Signed-off-by: Peter Zijlstra
    LKML-Reference:
    Signed-off-by: Ingo Molnar

    Peter Zijlstra
     
  • 00aec93d1   sched: Fully integrate cpus_active_map and root-domain code ... Browse Code »

    Reflect "active" cpus in the rq->rd->online field, instead of
    the online_map.

    The motivation is that things that use the root-domain code
    (such as cpupri) only care about cpus classified as "active"
    anyway. By synchronizing the root-domain state with the active
    map, we allow several optimizations.

    For instance, we can remove an extra cpumask_and from the
    scheduler hotpath by utilizing rq->rd->online (since it is now
    a cached version of cpu_active_map & rq->rd->span).

    Signed-off-by: Gregory Haskins
    Acked-by: Peter Zijlstra
    Acked-by: Max Krasnyansky
    Signed-off-by: Peter Zijlstra
    LKML-Reference:
    Signed-off-by: Ingo Molnar

    Gregory Haskins
     
  • 3f029d3c6   sched: Enhance the pre/post scheduling logic ... Browse Code »

    We currently have an explicit "needs_post" vtable method which
    returns a stack variable for whether we should later run
    post-schedule. This leads to an awkward exchange of the
    variable as it bubbles back up out of the context switch. Peter
    Zijlstra observed that this information could be stored in the
    run-queue itself instead of handled on the stack.

    Therefore, we revert to the method of having context_switch
    return void, and update an internal rq->post_schedule variable
    when we require further processing.

    In addition, we fix a race condition where we try to access
    current->sched_class without holding the rq->lock. This is
    technically racy, as the sched-class could change out from
    under us. Instead, we reference the per-rq post_schedule
    variable with the runqueue unlocked, but with preemption
    disabled to see if we need to reacquire the rq->lock.

    Finally, we clean the code up slightly by removing the #ifdef
    CONFIG_SMP conditionals from the schedule() call, and implement
    some inline helper functions instead.

    This patch passes checkpatch, and rt-migrate.

    Signed-off-by: Gregory Haskins
    Signed-off-by: Peter Zijlstra
    LKML-Reference:
    Signed-off-by: Ingo Molnar

    Gregory Haskins
     

10 Jul, 2009

1 commit

  • a1ba4d8ba   sched_rt: Fix overload bug on rt group scheduling ... Browse Code »

    Fixes an easily triggerable BUG() when setting process affinities.

    Make sure to count the number of migratable tasks in the same place:
    the root rt_rq. Otherwise the number doesn't make sense and we'll hit
    the BUG in set_cpus_allowed_rt().

    Also, make sure we only count tasks, not groups (this is probably
    already taken care of by the fact that rt_se->nr_cpus_allowed will be 0
    for groups, but be more explicit)

    Tested-by: Thomas Gleixner
    CC: stable@kernel.org
    Signed-off-by: Peter Zijlstra
    Acked-by: Gregory Haskins
    LKML-Reference:
    Signed-off-by: Ingo Molnar

    Peter Zijlstra
     

09 Jun, 2009

1 commit

08 Apr, 2009

1 commit

01 Apr, 2009

1 commit

28 Mar, 2009

1 commit

09 Feb, 2009

1 commit

01 Feb, 2009

1 commit

16 Jan, 2009

1 commit

  • ceacc2c1c   sched: make plist a library facility ... Browse Code »

    Ingo Molnar wrote:

    > here's a new build failure with tip/sched/rt:
    >
    > LD .tmp_vmlinux1
    > kernel/built-in.o: In function `set_curr_task_rt':
    > sched.c:(.text+0x3675): undefined reference to `plist_del'
    > kernel/built-in.o: In function `pick_next_task_rt':
    > sched.c:(.text+0x37ce): undefined reference to `plist_del'
    > kernel/built-in.o: In function `enqueue_pushable_task':
    > sched.c:(.text+0x381c): undefined reference to `plist_del'

    Eliminate the plist library kconfig and make it available
    unconditionally.

    Signed-off-by: Peter Zijlstra
    Signed-off-by: Ingo Molnar

    Peter Zijlstra
     

14 Jan, 2009

2 commits

12 Jan, 2009

1 commit

11 Jan, 2009

1 commit

04 Jan, 2009

2 commits

  • 6ca09dfc9   sched: put back some stack hog changes that were undone in kernel/sched.c ... Browse Code »

    Impact: prevents panic from stack overflow on numa-capable machines.

    Some of the "removal of stack hogs" changes in kernel/sched.c by using
    node_to_cpumask_ptr were undone by the early cpumask API updates, and
    causes a panic due to stack overflow. This patch undoes those changes
    by using cpumask_of_node() which returns a 'const struct cpumask *'.

    In addition, cpu_coregoup_map is replaced with cpu_coregroup_mask further
    reducing stack usage. (Both of these updates removed 9 FIXME's!)

    Also:
    Pick up some remaining changes from the old 'cpumask_t' functions to
    the new 'struct cpumask *' functions.

    Optimize memory traffic by allocating each percpu local_cpu_mask on the
    same node as the referring cpu.

    Signed-off-by: Mike Travis
    Acked-by: Rusty Russell
    Signed-off-by: Ingo Molnar

    Mike Travis
     
  • 7eb195533   Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/lin… ... Browse Code »

    …ux-2.6-cpumask into merge-rr-cpumask

    Conflicts:
    arch/x86/kernel/io_apic.c
    kernel/rcuclassic.c
    kernel/sched.c
    kernel/time/tick-sched.c

    Signed-off-by: Mike Travis <travis@sgi.com>
    [ mingo@elte.hu: backmerged typo fix for io_apic.c ]
    Signed-off-by: Ingo Molnar <mingo@elte.hu>

    Mike Travis
     

29 Dec, 2008

4 commits

  • 1563513d3   RT: fix push_rt_task() to handle dequeue_pushable properly ... Browse Code »

    A panic was discovered by Chirag Jog where a BUG_ON sanity check
    in the new "pushable_task" logic would trigger a panic under
    certain circumstances:

    http://lkml.org/lkml/2008/9/25/189

    Gilles Carry discovered that the root cause was attributed to the
    pushable_tasks list getting corrupted in the push_rt_task logic.
    This was the result of a dropped rq lock in double_lock_balance
    allowing a task in the process of being pushed to potentially migrate
    away, and thus corrupt the pushable_tasks() list.

    I traced back the problem as introduced by the pushable_tasks patch
    that went in recently. There is a "retry" path in push_rt_task()
    that actually had a compound conditional to decide whether to
    retry or exit. I missed the meaning behind the rationale for the
    virtual "if(!task) goto out;" portion of the compound statement and
    thus did not handle it properly. The new pushable_tasks logic
    actually creates three distinct conditions:

    1) an untouched and unpushable task should be dequeued
    2) a migrated task where more pushable tasks remain should be retried
    3) a migrated task where no more pushable tasks exist should exit

    The original logic mushed (1) and (3) together, resulting in the
    system dequeuing a migrated task (against an unlocked foreign run-queue
    nonetheless).

    To fix this, we get rid of the notion of "paranoid" and we support the
    three unique conditions properly. The paranoid feature is no longer
    relevant with the new pushable logic (since pushable naturally limits
    the loop) anyway, so lets just remove it.

    Reported-By: Chirag Jog
    Found-by: Gilles Carry
    Signed-off-by: Gregory Haskins

    Gregory Haskins
     
  • 917b627d4   sched: create "pushable_tasks" list to limit pushing to one attempt ... Browse Code »

    The RT scheduler employs a "push/pull" design to actively balance tasks
    within the system (on a per disjoint cpuset basis). When a task is
    awoken, it is immediately determined if there are any lower priority
    cpus which should be preempted. This is opposed to the way normal
    SCHED_OTHER tasks behave, which will wait for a periodic rebalancing
    operation to occur before spreading out load.

    When a particular RQ has more than 1 active RT task, it is said to
    be in an "overloaded" state. Once this occurs, the system enters
    the active balancing mode, where it will try to push the task away,
    or persuade a different cpu to pull it over. The system will stay
    in this state until the system falls back below the lock for certain workloads, and by making sure the algorithm
    considers all eligible tasks in the system.

    [ rostedt: added a couple more BUG_ONs ]

    Signed-off-by: Gregory Haskins
    Acked-by: Steven Rostedt

    Gregory Haskins
     
  • 967fc0467   sched: add sched_class->needs_post_schedule() member ... Browse Code »

    We currently run class->post_schedule() outside of the rq->lock, which
    means that we need to test for the need to post_schedule outside of
    the lock to avoid a forced reacquistion. This is currently not a problem
    as we only look at rq->rt.overloaded. However, we want to enhance this
    going forward to look at more state to reduce the need to post_schedule to
    a bare minimum set. Therefore, we introduce a new member-func called
    needs_post_schedule() which tests for the post_schedule condtion without
    actually performing the work. Therefore it is safe to call this
    function before the rq->lock is released, because we are guaranteed not
    to drop the lock at an intermediate point (such as what post_schedule()
    may do).

    We will use this later in the series

    [ rostedt: removed paranoid BUG_ON ]

    Signed-off-by: Gregory Haskins

    Gregory Haskins
     
  • 777c2f389   sched: only try to push a task on wakeup if it is migratable ... Browse Code »

    There is no sense in wasting time trying to push a task away that
    cannot move anywhere else. We gain no benefit from trying to push
    other tasks at this point, so if the task being woken up is non
    migratable, just skip the whole operation. This reduces overhead
    in the wakeup path for certain tasks.

    Signed-off-by: Gregory Haskins

    Gregory Haskins