lkml.org 
[lkml]   [2006]   [Sep]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    From
    Subject[patch 11/23] hrtimers: state tracking
    From: Thomas Gleixner <tglx@linutronix.de>

    reintroduce ktimers feature "optimized away" by the ktimers
    review process: multiple hrtimer states to enable the running
    of hrtimers without holding the cpu-base-lock.

    (the "optimized" rbtree hack carried only 2 states worth of
    information and we need 3.)

    Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
    Signed-off-by: Ingo Molnar <mingo@elte.hu>
    --
    include/linux/hrtimer.h | 7 +++++--
    kernel/hrtimer.c | 17 ++++++++++-------
    2 files changed, 15 insertions(+), 9 deletions(-)

    Index: linux-2.6.18-mm2/include/linux/hrtimer.h
    ===================================================================
    --- linux-2.6.18-mm2.orig/include/linux/hrtimer.h 2006-09-30 01:41:17.000000000 +0200
    +++ linux-2.6.18-mm2/include/linux/hrtimer.h 2006-09-30 01:41:17.000000000 +0200
    @@ -34,7 +34,9 @@ enum hrtimer_restart {
    HRTIMER_RESTART,
    };

    -#define HRTIMER_INACTIVE ((void *)1UL)
    +#define HRTIMER_INACTIVE 0x00
    +#define HRTIMER_ACTIVE 0x01
    +#define HRTIMER_CALLBACK 0x02

    struct hrtimer_clock_base;

    @@ -54,6 +56,7 @@ struct hrtimer {
    ktime_t expires;
    int (*function)(struct hrtimer *);
    struct hrtimer_clock_base *base;
    + unsigned long state;
    };

    /**
    @@ -139,7 +142,7 @@ extern ktime_t hrtimer_get_next_event(vo

    static inline int hrtimer_active(const struct hrtimer *timer)
    {
    - return rb_parent(&timer->node) != &timer->node;
    + return timer->state != HRTIMER_INACTIVE;
    }

    /* Forward a hrtimer so it expires after now: */
    Index: linux-2.6.18-mm2/kernel/hrtimer.c
    ===================================================================
    --- linux-2.6.18-mm2.orig/kernel/hrtimer.c 2006-09-30 01:41:17.000000000 +0200
    +++ linux-2.6.18-mm2/kernel/hrtimer.c 2006-09-30 01:41:17.000000000 +0200
    @@ -384,6 +384,7 @@ static void enqueue_hrtimer(struct hrtim
    */
    rb_link_node(&timer->node, parent, link);
    rb_insert_color(&timer->node, &base->active);
    + timer->state |= HRTIMER_ACTIVE;

    if (!base->first || timer->expires.tv64 <
    rb_entry(base->first, struct hrtimer, node)->expires.tv64)
    @@ -396,7 +397,8 @@ static void enqueue_hrtimer(struct hrtim
    * Caller must hold the base lock.
    */
    static void __remove_hrtimer(struct hrtimer *timer,
    - struct hrtimer_clock_base *base)
    + struct hrtimer_clock_base *base,
    + unsigned long newstate)
    {
    /*
    * Remove the timer from the rbtree and replace the
    @@ -405,7 +407,7 @@ static void __remove_hrtimer(struct hrti
    if (base->first == &timer->node)
    base->first = rb_next(&timer->node);
    rb_erase(&timer->node, &base->active);
    - rb_set_parent(&timer->node, &timer->node);
    + timer->state = newstate;
    }

    /*
    @@ -415,7 +417,7 @@ static inline int
    remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base)
    {
    if (hrtimer_active(timer)) {
    - __remove_hrtimer(timer, base);
    + __remove_hrtimer(timer, base, HRTIMER_INACTIVE);
    return 1;
    }
    return 0;
    @@ -487,7 +489,7 @@ int hrtimer_try_to_cancel(struct hrtimer

    base = lock_hrtimer_base(timer, &flags);

    - if (base->cpu_base->curr_timer != timer)
    + if (!(timer->state & HRTIMER_CALLBACK))
    ret = remove_hrtimer(timer, base);

    unlock_hrtimer_base(timer, &flags);
    @@ -592,7 +594,6 @@ void hrtimer_init(struct hrtimer *timer,
    clock_id = CLOCK_MONOTONIC;

    timer->base = &cpu_base->clock_base[clock_id];
    - rb_set_parent(&timer->node, &timer->node);
    }
    EXPORT_SYMBOL_GPL(hrtimer_init);

    @@ -643,13 +644,14 @@ static inline void run_hrtimer_queue(str

    fn = timer->function;
    set_curr_timer(cpu_base, timer);
    - __remove_hrtimer(timer, base);
    + __remove_hrtimer(timer, base, HRTIMER_CALLBACK);
    spin_unlock_irq(&cpu_base->lock);

    restart = fn(timer);

    spin_lock_irq(&cpu_base->lock);

    + timer->state &= ~HRTIMER_CALLBACK;
    if (restart != HRTIMER_NORESTART) {
    BUG_ON(hrtimer_active(timer));
    enqueue_hrtimer(timer, base);
    @@ -820,7 +822,8 @@ static void migrate_hrtimer_list(struct

    while ((node = rb_first(&old_base->active))) {
    timer = rb_entry(node, struct hrtimer, node);
    - __remove_hrtimer(timer, old_base);
    + BUG_ON(timer->state & HRTIMER_CALLBACK);
    + __remove_hrtimer(timer, old_base, HRTIMER_INACTIVE);
    timer->base = new_base;
    enqueue_hrtimer(timer, new_base);
    }
    --

    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2006-09-30 02:13    [W:0.026 / U:1.144 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site