Fix cpusets update_cpumask

#ifndef _LINUX_PRIO_HEAP_H

#define _LINUX_PRIO_HEAP_H

/*

 * Simple insertion-only static-sized priority heap containing

 * pointers, based on CLR, chapter 7

 */

#include <linux/gfp.h>

/**

 * struct ptr_heap - simple static-sized priority heap

 * @ptrs - pointer to data area

 * @max - max number of elements that can be stored in @ptrs

 * @size - current number of valid elements in @ptrs (in the range 0..@size-1

 * @gt: comparison operator, which should implement "greater than"

 */

struct ptr_heap {

	void **ptrs;

	int max;

	int size;

	int (*gt)(void *, void *);

};

/**

 * heap_init - initialize an empty heap with a given memory size

 * @heap: the heap structure to be initialized

 * @size: amount of memory to use in bytes

 * @gfp_mask: mask to pass to kmalloc()

 * @gt: comparison operator, which should implement "greater than"

 */

extern int heap_init(struct ptr_heap *heap, size_t size, gfp_t gfp_mask,

		     int (*gt)(void *, void *));

/**

 * heap_free - release a heap's storage

 * @heap: the heap structure whose data should be released

 */

void heap_free(struct ptr_heap *heap);

/**

 * heap_insert - insert a value into the heap and return any overflowed value

 * @heap: the heap to be operated on

 * @p: the pointer to be inserted

 *

 * Attempts to insert the given value into the priority heap. If the

 * heap is full prior to the insertion, then the resulting heap will

 * consist of the smallest @max elements of the original heap and the

 * new element; the greatest element will be removed from the heap and

 * returned. Note that the returned element will be the new element

 * (i.e. no change to the heap) if the new element is greater than all

 * elements currently in the heap.

 */

extern void *heap_insert(struct ptr_heap *heap, void *p);

#endif /* _LINUX_PRIO_HEAP_H */

#include <linux/mount.h>

#include <linux/namei.h>

#include <linux/pagemap.h>

#include <linux/prio_heap.h>

#include <linux/proc_fs.h>

#include <linux/rcupdate.h>

#include <linux/sched.h>

	/* Don't kfree(doms) -- partition_sched_domains() does that. */

}

static inline int started_after_time(struct task_struct *t1,

				     struct timespec *time,

				     struct task_struct *t2)

{

	int start_diff = timespec_compare(&t1->start_time, time);

	if (start_diff > 0) {

		return 1;

	} else if (start_diff < 0) {

		return 0;

	} else {

		/*

		 * Arbitrarily, if two processes started at the same

		 * time, we'll say that the lower pointer value

		 * started first. Note that t2 may have exited by now

		 * so this may not be a valid pointer any longer, but

		 * that's fine - it still serves to distinguish

		 * between two tasks started (effectively)

		 * simultaneously.

		 */

		return t1 > t2;

	}

}

static inline int started_after(void *p1, void *p2)

{

	struct task_struct *t1 = p1;

	struct task_struct *t2 = p2;

	return started_after_time(t1, &t2->start_time, t2);

}

/*

 * Call with manage_mutex held.  May take callback_mutex during call.

 */

static int update_cpumask(struct cpuset *cs, char *buf)

{

	struct cpuset trialcs;

	int retval;

	int cpus_changed, is_load_balanced;

	int retval, i;

	int is_load_balanced;

	struct cgroup_iter it;

	struct cgroup *cgrp = cs->css.cgroup;

	struct task_struct *p, *dropped;

	/* Never dereference latest_task, since it's not refcounted */

	struct task_struct *latest_task = NULL;

	struct ptr_heap heap;

	struct timespec latest_time = { 0, 0 };

	/* top_cpuset.cpus_allowed tracks cpu_online_map; it's read-only */

	if (cs == &top_cpuset)

	if (retval < 0)

		return retval;

	cpus_changed = !cpus_equal(cs->cpus_allowed, trialcs.cpus_allowed);

	/* Nothing to do if the cpus didn't change */

	if (cpus_equal(cs->cpus_allowed, trialcs.cpus_allowed))

		return 0;

	retval = heap_init(&heap, PAGE_SIZE, GFP_KERNEL, &started_after);

	if (retval)

		return retval;

	is_load_balanced = is_sched_load_balance(&trialcs);

	mutex_lock(&callback_mutex);

	cs->cpus_allowed = trialcs.cpus_allowed;

	mutex_unlock(&callback_mutex);

	if (cpus_changed && is_load_balanced)

 again:

	/*

	 * Scan tasks in the cpuset, and update the cpumasks of any

	 * that need an update. Since we can't call set_cpus_allowed()

	 * while holding tasklist_lock, gather tasks to be processed

	 * in a heap structure. If the statically-sized heap fills up,

	 * overflow tasks that started later, and in future iterations

	 * only consider tasks that started after the latest task in

	 * the previous pass. This guarantees forward progress and

	 * that we don't miss any tasks

	 */

	heap.size = 0;

	cgroup_iter_start(cgrp, &it);

	while ((p = cgroup_iter_next(cgrp, &it))) {

		/* Only affect tasks that don't have the right cpus_allowed */

		if (cpus_equal(p->cpus_allowed, cs->cpus_allowed))

			continue;

		/*

		 * Only process tasks that started after the last task

		 * we processed

		 */

		if (!started_after_time(p, &latest_time, latest_task))

			continue;

		dropped = heap_insert(&heap, p);

		if (dropped == NULL) {

			get_task_struct(p);

		} else if (dropped != p) {

			get_task_struct(p);

			put_task_struct(dropped);

		}

	}

	cgroup_iter_end(cgrp, &it);

	if (heap.size) {

		for (i = 0; i < heap.size; i++) {

			struct task_struct *p = heap.ptrs[i];

			if (i == 0) {

				latest_time = p->start_time;

				latest_task = p;

			}

			set_cpus_allowed(p, cs->cpus_allowed);

			put_task_struct(p);

		}

		/*

		 * If we had to process any tasks at all, scan again

		 * in case some of them were in the middle of forking

		 * children that didn't notice the new cpumask

		 * restriction.  Not the most efficient way to do it,

		 * but it avoids having to take callback_mutex in the

		 * fork path

		 */

		goto again;

	}

	heap_free(&heap);

	if (is_load_balanced)

		rebuild_sched_domains();

	return 0;

	cpus_allowed = cpuset_cpus_allowed(p);

	cpus_and(new_mask, new_mask, cpus_allowed);

 again:

	retval = set_cpus_allowed(p, new_mask);

	if (!retval) {

		cpus_allowed = cpuset_cpus_allowed(p);

		if (!cpus_subset(new_mask, cpus_allowed)) {

			/*

			 * We must have raced with a concurrent cpuset

			 * update. Just reset the cpus_allowed to the

			 * cpuset's cpus_allowed

			 */

			new_mask = cpus_allowed;

			goto again;

		}

	}

out_unlock:

	put_task_struct(p);

	mutex_unlock(&sched_hotcpu_mutex);

	 rbtree.o radix-tree.o dump_stack.o \

	 idr.o int_sqrt.o bitmap.o extable.o prio_tree.o \

	 sha1.o irq_regs.o reciprocal_div.o argv_split.o \

	 proportions.o

	 proportions.o prio_heap.o

lib-$(CONFIG_MMU) += ioremap.o

lib-$(CONFIG_SMP) += cpumask.o

/*

 * Simple insertion-only static-sized priority heap containing

 * pointers, based on CLR, chapter 7

 */

#include <linux/slab.h>

#include <linux/prio_heap.h>

int heap_init(struct ptr_heap *heap, size_t size, gfp_t gfp_mask,

	      int (*gt)(void *, void *))

{

	heap->ptrs = kmalloc(size, gfp_mask);

	if (!heap->ptrs)

		return -ENOMEM;

	heap->size = 0;

	heap->max = size / sizeof(void *);

	heap->gt = gt;

	return 0;

}

void heap_free(struct ptr_heap *heap)

{

	kfree(heap->ptrs);

}

void *heap_insert(struct ptr_heap *heap, void *p)

{

	void *res;

	void **ptrs = heap->ptrs;

	int pos;

	if (heap->size < heap->max) {

		/* Heap insertion */

		int pos = heap->size++;

		while (pos > 0 && heap->gt(p, ptrs[(pos-1)/2])) {

			ptrs[pos] = ptrs[(pos-1)/2];

			pos = (pos-1)/2;

		}

		ptrs[pos] = p;

		return NULL;

	}

	/* The heap is full, so something will have to be dropped */

	/* If the new pointer is greater than the current max, drop it */

	if (heap->gt(p, ptrs[0]))

		return p;

	/* Replace the current max and heapify */

	res = ptrs[0];

	ptrs[0] = p;

	pos = 0;

	while (1) {

		int left = 2 * pos + 1;

		int right = 2 * pos + 2;

		int largest = pos;

		if (left < heap->size && heap->gt(ptrs[left], p))

			largest = left;

		if (right < heap->size && heap->gt(ptrs[right], ptrs[largest]))

			largest = right;

		if (largest == pos)

			break;

		/* Push p down the heap one level and bump one up */

		ptrs[pos] = ptrs[largest];

		ptrs[largest] = p;

		pos = largest;

	}

	return res;

}