Messages in this thread Patch in this message | | | Date | Mon, 1 Nov 2004 13:51:27 +0100 | From | Ingo Molnar <> | Subject | Re: [Fwd: Re: [patch] Real-Time Preemption, -RT-2.6.9-mm1-V0.4] |
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* Thomas Gleixner <tglx@linutronix.de> wrote:
> I'm doing some tests from my RT environment on 0.6.2. I'm quite sure, > that interrupts are sporadically disabled for > 200µs. Did you change > anything relevant to this between 0.6.2 and 0.6.4 ?
hm, i changed the task-exit schedule() to be called with irqs-off and __schedule() - but that should be fine. I've attached the delta diff - there's nothing suspicious at first sight. Maybe -V0.6.4 just made some already existing bug more likely to trigger? I am too seeing rtc_wakeup weirdnesses that were not present in earlier -V0.6 kernels.
Ingo
--- linux.old/Makefile +++ linux.new/Makefile @@ -1,7 +1,7 @@ VERSION = 2 PATCHLEVEL = 6 SUBLEVEL = 9 -EXTRAVERSION = -mm1-RT-V0.6.2 +EXTRAVERSION = -mm1-RT-V0.6.4 NAME=Zonked Quokka # *DOCUMENTATION* --- linux.old/kernel/exit.c +++ linux.new/kernel/exit.c @@ -840,9 +840,9 @@ asmlinkage NORET_TYPE void do_exit(long #endif check_no_held_locks(tsk); /* PF_DEAD causes final put_task_struct after we schedule. */ - wmb(); + local_irq_disable(); tsk->flags |= PF_DEAD; - schedule(); + __schedule(); BUG(); /* Avoid "noreturn function does return". */ for (;;) ; --- linux.old/kernel/sched.c +++ linux.new/kernel/sched.c @@ -599,13 +599,11 @@ static inline void enqueue_task_head(str * * Both properties are important to certain workloads. */ -static int effective_prio(task_t *p) + +static inline int __effective_prio(task_t *p) { int bonus, prio; - if (rt_task(p)) - return p->prio; - bonus = CURRENT_BONUS(p) - MAX_BONUS / 2; prio = p->static_prio - bonus; @@ -616,6 +614,13 @@ static int effective_prio(task_t *p) return prio; } +static int effective_prio(task_t *p) +{ + if (rt_task(p)) + return p->prio; + return __effective_prio(p); +} + /* * __activate_task - move a task to the runqueue. */ @@ -3540,8 +3545,7 @@ int mutex_getprio(task_t *p) if (p->policy != SCHED_NORMAL) return MAX_USER_RT_PRIO-1 - p->rt_priority; else -// return effective_prio(p); - return p->static_prio; + return __effective_prio(p); } /* @@ -3559,15 +3563,14 @@ void mutex_setprio(task_t *p, int prio) rq = task_rq_lock(p, &flags); + oldprio = p->prio; array = p->array; if (array) - deactivate_task(p, rq); - oldprio = p->prio; - + dequeue_task(p, array); p->prio = prio; if (array) { - __activate_task(p, rq); + enqueue_task(p, array); /* * Reschedule if we are currently running on this runqueue and * our priority decreased, or if we are not currently running on --- linux.old/kernel/timer.c +++ linux.new/kernel/timer.c @@ -956,23 +956,25 @@ EXPORT_SYMBOL(xtime_lock); */ static inline void update_times(void) { + unsigned long ticks = 0; /* * First test outside the lock for performance reasons: */ - if (jiffies - wall_jiffies) { + if (jiffies != wall_jiffies) { unsigned long flags; write_seqlock_irqsave(&xtime_lock, flags); - while (jiffies - wall_jiffies) { + while (jiffies != wall_jiffies) { wall_jiffies++; + ticks++; update_wall_time(1); - calc_load(1); if (seqlock_need_resched(&xtime_lock)) { write_sequnlock_irqrestore(&xtime_lock, flags); cond_resched(); write_seqlock_irqsave(&xtime_lock, flags); } } + calc_load(ticks); write_sequnlock_irqrestore(&xtime_lock, flags); } } - 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/
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