C++ rt_task函数代码示例

static void
probe_wakeup(struct rq *rq, struct task_struct *p, int success)
{
    struct trace_array_cpu *data;
    int cpu = smp_processor_id();
    unsigned long flags;
    long disabled;
    int pc;

    if (likely(!tracer_enabled))
        return;

    tracing_record_cmdline(p);
    tracing_record_cmdline(current);

    if ((wakeup_rt && !rt_task(p)) ||
            p->prio >= wakeup_prio ||
            p->prio >= current->prio)
        return;

    pc = preempt_count();
    disabled = atomic_inc_return(&wakeup_trace->data[cpu]->disabled);
    if (unlikely(disabled != 1))
        goto out;

    /* interrupts should be off from try_to_wake_up */
    __raw_spin_lock(&wakeup_lock);

    /* check for races. */
    if (!tracer_enabled || p->prio >= wakeup_prio)
        goto out_locked;

    /* reset the trace */
    __wakeup_reset(wakeup_trace);

    wakeup_cpu = task_cpu(p);
    wakeup_current_cpu = wakeup_cpu;
    wakeup_prio = p->prio;

    wakeup_task = p;
    get_task_struct(wakeup_task);

    local_save_flags(flags);

    data = wakeup_trace->data[wakeup_cpu];
    data->preempt_timestamp = ftrace_now(cpu);
    tracing_sched_wakeup_trace(wakeup_trace, p, current, flags, pc);

    /*
     * We must be careful in using CALLER_ADDR2. But since wake_up
     * is not called by an assembly function  (where as schedule is)
     * it should be safe to use it here.
     */
    trace_function(wakeup_trace, CALLER_ADDR1, CALLER_ADDR2, flags, pc);

out_locked:
    __raw_spin_unlock(&wakeup_lock);
out:
    atomic_dec(&wakeup_trace->data[cpu]->disabled);
}

/*
 * global_dirty_limits - background-writeback and dirty-throttling thresholds
 *
 * Calculate the dirty thresholds based on sysctl parameters
 * - vm.dirty_background_ratio  or  vm.dirty_background_bytes
 * - vm.dirty_ratio             or  vm.dirty_bytes
 * The dirty limits will be lifted by 1/4 for PF_LESS_THROTTLE (ie. nfsd) and
 * real-time tasks.
 */
void global_dirty_limits(unsigned long *pbackground, unsigned long *pdirty)
{
	unsigned long background;
	unsigned long dirty;
	unsigned long uninitialized_var(available_memory);
	struct task_struct *tsk;

	if (!vm_dirty_bytes || !dirty_background_bytes)
		available_memory = determine_dirtyable_memory();

	if (vm_dirty_bytes)
		dirty = DIV_ROUND_UP(vm_dirty_bytes, PAGE_SIZE);
	else
		dirty = (vm_dirty_ratio * available_memory) / 100;

	if (dirty_background_bytes)
		background = DIV_ROUND_UP(dirty_background_bytes, PAGE_SIZE);
	else
		background = (dirty_background_ratio * available_memory) / 100;

	if (background >= dirty)
		background = dirty / 2;
	tsk = current;
	if (tsk->flags & PF_LESS_THROTTLE || rt_task(tsk)) {
		background += background / 4;
		dirty += dirty / 4;
	}
	*pbackground = background;
	*pdirty = dirty;
}

long hrtimer_nanosleep(const struct timespec64 *rqtp,
		       const enum hrtimer_mode mode, const clockid_t clockid)
{
	struct restart_block *restart;
	struct hrtimer_sleeper t;
	int ret = 0;
	u64 slack;

	slack = current->timer_slack_ns;
	if (dl_task(current) || rt_task(current))
		slack = 0;

	hrtimer_init_on_stack(&t.timer, clockid, mode);
	hrtimer_set_expires_range_ns(&t.timer, timespec64_to_ktime(*rqtp), slack);
	ret = do_nanosleep(&t, mode);
	if (ret != -ERESTART_RESTARTBLOCK)
		goto out;

	/* Absolute timers do not update the rmtp value and restart: */
	if (mode == HRTIMER_MODE_ABS) {
		ret = -ERESTARTNOHAND;
		goto out;
	}

	restart = &current->restart_block;
	restart->fn = hrtimer_nanosleep_restart;
	restart->nanosleep.clockid = t.timer.base->clockid;
	restart->nanosleep.expires = hrtimer_get_expires_tv64(&t.timer);
out:
	destroy_hrtimer_on_stack(&t.timer);
	return ret;
}

static void
probe_wakeup(struct rq *rq, struct task_struct *p, int success)
{
	int cpu = smp_processor_id();
	unsigned long flags;
	long disabled;
	int pc;

	if (likely(!tracer_enabled))
		return;

	tracing_record_cmdline(p);
	tracing_record_cmdline(current);

	if (likely(!rt_task(p)) ||
			p->prio >= wakeup_prio ||
			p->prio >= current->prio)
		return;

	pc = preempt_count();
	disabled = atomic_inc_return(&wakeup_trace->data[cpu]->disabled);
	if (unlikely(disabled != 1))
		goto out;

	/* interrupts should be off from try_to_wake_up */
	__raw_spin_lock(&wakeup_lock);

	/* check for races. */
	if (!tracer_enabled || p->prio >= wakeup_prio)
		goto out_locked;

	/* reset the trace */
	__wakeup_reset(wakeup_trace);

	wakeup_cpu = task_cpu(p);
	wakeup_prio = p->prio;

	wakeup_task = p;
	get_task_struct(wakeup_task);

	local_save_flags(flags);

	wakeup_trace->data[wakeup_cpu]->preempt_timestamp = ftrace_now(cpu);
	trace_function(wakeup_trace, wakeup_trace->data[wakeup_cpu],
		       CALLER_ADDR1, CALLER_ADDR2, flags, pc);

out_locked:
	__raw_spin_unlock(&wakeup_lock);
out:
	atomic_dec(&wakeup_trace->data[cpu]->disabled);
}

void
get_dirty_limits(long *pbackground, long *pdirty, long *pbdi_dirty,
		 struct backing_dev_info *bdi)
{
	int background_ratio;		/* Percentages */
	int dirty_ratio;
	long background;
	long dirty;
	unsigned long available_memory = determine_dirtyable_memory();
	struct task_struct *tsk;

	dirty_ratio = vm_dirty_ratio;
	if (dirty_ratio < 5)
		dirty_ratio = 5;

	background_ratio = dirty_background_ratio;
	if (background_ratio >= dirty_ratio)
		background_ratio = dirty_ratio / 2;

	background = (background_ratio * available_memory) / 100;
	dirty = (dirty_ratio * available_memory) / 100;
	tsk = current;
	if (tsk->flags & PF_LESS_THROTTLE || rt_task(tsk)) {
		background += background / 4;
		dirty += dirty / 4;
	}
	*pbackground = background;
	*pdirty = dirty;

	if (bdi) {
		u64 bdi_dirty;
		long numerator, denominator;

		/*
		 * Calculate this BDI's share of the dirty ratio.
		 */
		bdi_writeout_fraction(bdi, &numerator, &denominator);

		bdi_dirty = (dirty * (100 - bdi_min_ratio)) / 100;
		bdi_dirty *= numerator;
		do_div(bdi_dirty, denominator);
		bdi_dirty += (dirty * bdi->min_ratio) / 100;
		if (bdi_dirty > (dirty * bdi->max_ratio) / 100)
			bdi_dirty = dirty * bdi->max_ratio / 100;

		*pbdi_dirty = bdi_dirty;
		clip_bdi_dirty_limit(bdi, dirty, pbdi_dirty);
		task_dirty_limit(current, pbdi_dirty);
	}
}

/*
 * Work out the current dirty-memory clamping and background writeout
 * thresholds.
 *
 * The main aim here is to lower them aggressively if there is a lot of mapped
 * memory around.  To avoid stressing page reclaim with lots of unreclaimable
 * pages.  It is better to clamp down on writers than to start swapping, and
 * performing lots of scanning.
 *
 * We only allow 1/2 of the currently-unmapped memory to be dirtied.
 *
 * We don't permit the clamping level to fall below 5% - that is getting rather
 * excessive.
 *
 * We make sure that the background writeout level is below the adjusted
 * clamping level.
 */
static void
get_dirty_limits(long *pbackground, long *pdirty,
					struct address_space *mapping)
{
	int background_ratio;		/* Percentages */
	int dirty_ratio;
	int unmapped_ratio;
	long background;
	long dirty;
	unsigned long available_memory = vm_total_pages;
	struct task_struct *tsk;

#ifdef CONFIG_HIGHMEM
	/*
	 * We always exclude high memory from our count.
	 */
	available_memory -= totalhigh_pages;
#endif


	unmapped_ratio = 100 - ((global_page_state(NR_FILE_MAPPED) +
				global_page_state(NR_ANON_PAGES)) * 100) /
					vm_total_pages;

	dirty_ratio = vm_dirty_ratio;
	if (dirty_ratio > unmapped_ratio / 2)
		dirty_ratio = unmapped_ratio / 2;

	if (dirty_ratio < 5)
		dirty_ratio = 5;

	background_ratio = dirty_background_ratio;
	if (background_ratio >= dirty_ratio)
		background_ratio = dirty_ratio / 2;

	background = (background_ratio * available_memory) / 100;
	dirty = (dirty_ratio * available_memory) / 100;
	tsk = current;
	if (tsk->flags & PF_LESS_THROTTLE || rt_task(tsk)) {
		background += background / 4;
		dirty += dirty / 4;
	}
	*pbackground = background;
	*pdirty = dirty;
}

static long estimate_accuracy(struct timespec *tv)
{
	unsigned long ret;
	struct timespec now;

	/*
	 * Realtime tasks get a slack of 0 for obvious reasons.
	 */

	if (rt_task(current))
		return 0;

	ktime_get_ts(&now);
	now = timespec_sub(*tv, now);
	ret = __estimate_accuracy(&now);
	if (ret < current->timer_slack_ns)
		return current->timer_slack_ns;
	return ret;
}

long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp,
		       const enum hrtimer_mode mode, const clockid_t clockid)
{
	struct restart_block *restart;
	struct hrtimer_sleeper t;
	int ret = 0;
	unsigned long slack;

	slack = current->timer_slack_ns;
	if (rt_task(current))
		slack = 0;

	hrtimer_init_on_stack(&t.timer, clockid, mode);
	hrtimer_set_expires_range_ns(&t.timer, timespec_to_ktime(*rqtp), slack);
	if (do_nanosleep(&t, mode))
		goto out;

	/* Absolute timers do not update the rmtp value and restart: */
	if (mode == HRTIMER_MODE_ABS) {
		ret = -ERESTARTNOHAND;
		goto out;
	}

	if (rmtp) {
		ret = update_rmtp(&t.timer, rmtp);
		if (ret <= 0)
			goto out;
	}

	restart = &current_thread_info()->restart_block;
	restart->fn = hrtimer_nanosleep_restart;
	restart->nanosleep.clockid = t.timer.base->clockid;
	restart->nanosleep.rmtp = rmtp;
	restart->nanosleep.expires = hrtimer_get_expires_tv64(&t.timer);

	ret = -ERESTART_RESTARTBLOCK;
out:
	destroy_hrtimer_on_stack(&t.timer);
	return ret;
}

static void
get_dirty_limits(long *pbackground, long *pdirty,
					struct address_space *mapping)
{
	int background_ratio;		/* Percentages */
	int dirty_ratio;
	int unmapped_ratio;
	long background;
	long dirty;
	unsigned long available_memory = determine_dirtyable_memory();
	struct task_struct *tsk;

	unmapped_ratio = 100 - ((global_page_state(NR_FILE_MAPPED) +
				global_page_state(NR_ANON_PAGES)) * 100) /
					available_memory;

	dirty_ratio = vm_dirty_ratio;
	if (dirty_ratio > unmapped_ratio / 2)
		dirty_ratio = unmapped_ratio / 2;

	if (dirty_ratio < 5)
		dirty_ratio = 5;

	background_ratio = dirty_background_ratio;
	if (background_ratio >= dirty_ratio)
		background_ratio = dirty_ratio / 2;

	background = (background_ratio * available_memory) / 100;
	dirty = (dirty_ratio * available_memory) / 100;
	tsk = current;
	if (tsk->flags & PF_LESS_THROTTLE || rt_task(tsk)) {
		background += background / 4;
		dirty += dirty / 4;
	}
	*pbackground = background;
	*pdirty = dirty;
}

/*
 * Lock a mutex (possibly interruptible), slowpath:
 */
static inline int __sched
__mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
		    struct lockdep_map *nest_lock, unsigned long ip)
{
	struct task_struct *task = current;
	struct mutex_waiter waiter;
	unsigned long flags;

	preempt_disable();
	mutex_acquire_nest(&lock->dep_map, subclass, 0, nest_lock, ip);

#ifdef CONFIG_MUTEX_SPIN_ON_OWNER
	/*
	 * Optimistic spinning.
	 *
	 * We try to spin for acquisition when we find that there are no
	 * pending waiters and the lock owner is currently running on a
	 * (different) CPU.
	 *
	 * The rationale is that if the lock owner is running, it is likely to
	 * release the lock soon.
	 *
	 * Since this needs the lock owner, and this mutex implementation
	 * doesn't track the owner atomically in the lock field, we need to
	 * track it non-atomically.
	 *
	 * We can't do this for DEBUG_MUTEXES because that relies on wait_lock
	 * to serialize everything.
	 *
	 * The mutex spinners are queued up using MCS lock so that only one
	 * spinner can compete for the mutex. However, if mutex spinning isn't
	 * going to happen, there is no point in going through the lock/unlock
	 * overhead.
	 */
	if (!mutex_can_spin_on_owner(lock))
		goto slowpath;

	for (;;) {
		struct task_struct *owner;
		struct mspin_node  node;

		/*
		 * If there's an owner, wait for it to either
		 * release the lock or go to sleep.
		 */
		mspin_lock(MLOCK(lock), &node);
		owner = ACCESS_ONCE(lock->owner);
		if (owner && !mutex_spin_on_owner(lock, owner)) {
			mspin_unlock(MLOCK(lock), &node);
			break;
		}

		if ((atomic_read(&lock->count) == 1) &&
		    (atomic_cmpxchg(&lock->count, 1, 0) == 1)) {
			lock_acquired(&lock->dep_map, ip);
			mutex_set_owner(lock);
			mspin_unlock(MLOCK(lock), &node);
			preempt_enable();
			return 0;
		}
		mspin_unlock(MLOCK(lock), &node);

		/*
		 * When there's no owner, we might have preempted between the
		 * owner acquiring the lock and setting the owner field. If
		 * we're an RT task that will live-lock because we won't let
		 * the owner complete.
		 */
		if (!owner && (need_resched() || rt_task(task)))
			break;

		/*
		 * The cpu_relax() call is a compiler barrier which forces
		 * everything in this loop to be re-loaded. We don't need
		 * memory barriers as we'll eventually observe the right
		 * values at the cost of a few extra spins.
		 */
		arch_mutex_cpu_relax();
	}
slowpath:
#endif
	spin_lock_mutex(&lock->wait_lock, flags);

	debug_mutex_lock_common(lock, &waiter);
	debug_mutex_add_waiter(lock, &waiter, task_thread_info(task));

	/* add waiting tasks to the end of the waitqueue (FIFO): */
	list_add_tail(&waiter.list, &lock->wait_list);
	waiter.task = task;

	if (MUTEX_SHOW_NO_WAITER(lock) && (atomic_xchg(&lock->count, -1) == 1))
		goto done;

	lock_contended(&lock->dep_map, ip);

	for (;;) {
		/*
//.........这里部分代码省略.........

//.........这里部分代码省略.........
            timestamp_rel = 1;
        case 'T':
            with_timestamp = 1;
            break;

        default:
            fprintf(stderr, "Unknown option %c\n", opt);
            break;
        }
    }

    ret = rt_dev_socket(PF_CAN, SOCK_RAW, CAN_RAW);
    if (ret < 0) {
        fprintf(stderr, "rt_dev_socket: %s\n", strerror(-ret));
        return -1;
    }
    s = ret;

    if (argv[optind] == NULL) {
        if (verbose)
            printf("interface all\n");

        ifr.ifr_ifindex = 0;
    } else {
        if (verbose)
            printf("interface %s\n", argv[optind]);

        strncpy(ifr.ifr_name, argv[optind], IFNAMSIZ);
        if (verbose)
            printf("s=%d, ifr_name=%s\n", s, ifr.ifr_name);

        ret = rt_dev_ioctl(s, SIOCGIFINDEX, &ifr);
        if (ret < 0) {
            fprintf(stderr, "rt_dev_ioctl GET_IFINDEX: %s\n", strerror(-ret));
            goto failure;
        }
    }

    if (err_mask) {
        ret = rt_dev_setsockopt(s, SOL_CAN_RAW, CAN_RAW_ERR_FILTER,
                                &err_mask, sizeof(err_mask));
        if (ret < 0) {
            fprintf(stderr, "rt_dev_setsockopt: %s\n", strerror(-ret));
            goto failure;
        }
        if (verbose)
            printf("Using err_mask=%#x\n", err_mask);
    }

    if (filter_count) {
        ret = rt_dev_setsockopt(s, SOL_CAN_RAW, CAN_RAW_FILTER,
                                &recv_filter, filter_count *
                                sizeof(struct can_filter));
        if (ret < 0) {
            fprintf(stderr, "rt_dev_setsockopt: %s\n", strerror(-ret));
            goto failure;
        }
    }

    recv_addr.can_family = AF_CAN;
    recv_addr.can_ifindex = ifr.ifr_ifindex;
    ret = rt_dev_bind(s, (struct sockaddr *)&recv_addr,
                      sizeof(struct sockaddr_can));
    if (ret < 0) {
        fprintf(stderr, "rt_dev_bind: %s\n", strerror(-ret));
        goto failure;
    }

    if (timeout) {
        if (verbose)
            printf("Timeout: %lld ns\n", (long long)timeout);
        ret = rt_dev_ioctl(s, RTCAN_RTIOC_RCV_TIMEOUT, &timeout);
        if (ret) {
            fprintf(stderr, "rt_dev_ioctl RCV_TIMEOUT: %s\n", strerror(-ret));
            goto failure;
        }
    }

    if (with_timestamp) {
        ret = rt_dev_ioctl(s, RTCAN_RTIOC_TAKE_TIMESTAMP, RTCAN_TAKE_TIMESTAMPS);
        if (ret) {
            fprintf(stderr, "rt_dev_ioctl TAKE_TIMESTAMP: %s\n", strerror(-ret));
            goto failure;
        }
    }

    snprintf(name, sizeof(name), "rtcanrecv-%d", getpid());
    ret = rt_task_shadow(&rt_task_desc, name, 0, 0);
    if (ret) {
        fprintf(stderr, "rt_task_shadow: %s\n", strerror(-ret));
        goto failure;
    }

    rt_task();
    /* never returns */

failure:
    cleanup();
    return -1;
}

//.........这里部分代码省略.........
    }

    if (argv[optind] == NULL) {
	fprintf(stderr, "No Interface supplied\n");
	exit(-1);
    }

    if (verbose)
	printf("interface %s\n", argv[optind]);

    ret = socket(PF_CAN, SOCK_RAW, CAN_RAW);
    if (ret < 0) {
	fprintf(stderr, "socket: %s\n", strerror(-ret));
	return -1;
    }
    s = ret;

    if (loopback >= 0) {
	ret = setsockopt(s, SOL_CAN_RAW, CAN_RAW_LOOPBACK,
				&loopback, sizeof(loopback));
	if (ret < 0) {
	    fprintf(stderr, "setsockopt: %s\n", strerror(-ret));
	    goto failure;
	}
	if (verbose)
	    printf("Using loopback=%d\n", loopback);
    }

    strncpy(ifr.ifr_name, argv[optind], IFNAMSIZ);
    if (verbose)
	printf("s=%d, ifr_name=%s\n", s, ifr.ifr_name);

    ret = ioctl(s, SIOCGIFINDEX, &ifr);
    if (ret < 0) {
	fprintf(stderr, "ioctl: %s\n", strerror(-ret));
	goto failure;
    }

    memset(&to_addr, 0, sizeof(to_addr));
    to_addr.can_ifindex = ifr.ifr_ifindex;
    to_addr.can_family = AF_CAN;
    if (use_send) {
	/* Suppress definiton of a default receive filter list */
	ret = setsockopt(s, SOL_CAN_RAW, CAN_RAW_FILTER, NULL, 0);
	if (ret < 0) {
	    fprintf(stderr, "setsockopt: %s\n", strerror(-ret));
	    goto failure;
	}

	ret = bind(s, (struct sockaddr *)&to_addr, sizeof(to_addr));
	if (ret < 0) {
	    fprintf(stderr, "bind: %s\n", strerror(-ret));
	    goto failure;
	}
    }

    if (count)
	frame.can_dlc = sizeof(int);
    else {
	for (i = optind + 1; i < argc; i++) {
	    frame.data[dlc] = strtoul(argv[i], NULL, 0);
	    dlc++;
	    if( dlc == 8 )
		break;
	}
	frame.can_dlc = dlc;
    }

    if (rtr)
	frame.can_id |= CAN_RTR_FLAG;

    if (extended)
	frame.can_id |= CAN_EFF_FLAG;

    if (timeout) {
	if (verbose)
	    printf("Timeout: %lld ns\n", (long long)timeout);
	ret = ioctl(s, RTCAN_RTIOC_SND_TIMEOUT, &timeout);
	if (ret) {
	    fprintf(stderr, "ioctl SND_TIMEOUT: %s\n", strerror(-ret));
	    goto failure;
	}
    }

    snprintf(name, sizeof(name), "rtcansend-%d", getpid());
    ret = rt_task_shadow(&rt_task_desc, name, 1, 0);
    if (ret) {
	fprintf(stderr, "rt_task_shadow: %s\n", strerror(-ret));
	goto failure;
    }

    rt_task();

    cleanup();
    return 0;

 failure:
    cleanup();
    return -1;
}

/*
 * If this is a system OOM (not a memcg OOM) and the task selected to be
 * killed is not already running at high (RT) priorities, speed up the
 * recovery by boosting the dying task to the lowest FIFO priority.
 * That helps with the recovery and avoids interfering with RT tasks.
 */
static void boost_dying_task_prio(struct task_struct *p,
				  struct mem_cgroup *mem)
{
	struct sched_param param = { .sched_priority = 1 };

	if (mem)
		return;

	if (!rt_task(p))
		sched_setscheduler_nocheck(p, SCHED_FIFO, &param);
}

/*
 * The process p may have detached its own ->mm while exiting or through
 * use_mm(), but one or more of its subthreads may still have a valid
 * pointer.  Return p, or any of its subthreads with a valid ->mm, with
 * task_lock() held.
 */
struct task_struct *find_lock_task_mm(struct task_struct *p)
{
	struct task_struct *t = p;

	do {
		task_lock(t);
		if (likely(t->mm))
			return t;
		task_unlock(t);
	} while_each_thread(p, t);

	return NULL;
}

/* return true if the task is not adequate as candidate victim task. */
static bool oom_unkillable_task(struct task_struct *p,
		const struct mem_cgroup *mem, const nodemask_t *nodemask)
{
	if (is_global_init(p))
		return true;
	if (p->flags & PF_KTHREAD)
		return true;

	/* When mem_cgroup_out_of_memory() and p is not member of the group */
	if (mem && !task_in_mem_cgroup(p, mem))
		return true;

	/* p may not have freeable memory in nodemask */
	if (!has_intersects_mems_allowed(p, nodemask))
		return true;

	return false;
}

/**
 * oom_badness - heuristic function to determine which candidate task to kill
 * @p: task struct of which task we should calculate
 * @totalpages: total present RAM allowed for page allocation
 *
 * The heuristic for determining which task to kill is made to be as simple and
 * predictable as possible.  The goal is to return the highest value for the
 * task consuming the most memory to avoid subsequent oom failures.
 */
unsigned int oom_badness(struct task_struct *p, struct mem_cgroup *mem,
		      const nodemask_t *nodemask, unsigned long totalpages)
{
	long points;

	if (oom_unkillable_task(p, mem, nodemask))
		return 0;

	p = find_lock_task_mm(p);
	if (!p)
		return 0;

	/*
	 * Shortcut check for a thread sharing p->mm that is OOM_SCORE_ADJ_MIN
	 * so the entire heuristic doesn't need to be executed for something
	 * that cannot be killed.
	 */
	if (atomic_read(&p->mm->oom_disable_count)) {
		task_unlock(p);
		return 0;
	}

	/*
	 * The memory controller may have a limit of 0 bytes, so avoid a divide
	 * by zero, if necessary.
	 */
	if (!totalpages)
		totalpages = 1;

	/*
	 * The baseline for the badness score is the proportion of RAM that each
	 * task's rss, pagetable and swap space use.
	 */
//.........这里部分代码省略.........