common/os/pool.c

	pool.c revision fec0805b73d9516e40c83a7960968cfc6eebffaa
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <sys/pool.h>
#include <sys/pool_impl.h>
#include <sys/pool_pset.h>
#include <sys/id_space.h>
#include <sys/mutex.h>
#include <sys/nvpair.h>
#include <sys/cpuvar.h>
#include <sys/errno.h>
#include <sys/cmn_err.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/fss.h>
#include <sys/class.h>
#include <sys/exacct.h>
#include <sys/utsname.h>
#include <sys/procset.h>
#include <sys/atomic.h>
#include <sys/zone.h>
#include <sys/policy.h>
#include <sys/schedctl.h>

/*
 * RESOURCE POOLS
 *
 * The resource pools facility brings together process-bindable resource into
 * a common abstraction called a pool. Processor sets and other entities can
 * be configured, grouped, and labelled such that workload components can be
 * associated with a subset of a system's total resources.
 *
 * When disabled, the pools facility is "invisible".  All processes belong
 * to the same pool (pool_default), and processor sets can be managed through
 * the old pset() system call.  When enabled, processor sets can only be
 * managed via the pools facility.  New pools can be created and associated
 * with processor sets.  Processes can be bound to pools which have non-empty
 * resource sets.
 *
 * Locking: pool_lock() protects global pools state and must be called
 * before modifying the configuration, or when taking a snapshot of the
 * configuration.  If pool_lock_intr() is used, the operation may be
 * interrupted by a signal or a request.
 *
 * To prevent processes from being rebound between pools while they are
 * the middle of an operation which affects resource set bindings, such
 * operations must be surrounded by calls to pool_barrier_enter() and
 * pool_barrier_exit().  This mechanism guarantees that such processes will
 * be stopped either at the beginning or at the end of the barrier so that
 * the rebind operation can atomically bind the process and its threads
 * to new resource sets, and then let process run again.
 *
 * Lock ordering with respect to other locks is as follows:
 *
 *  pool_lock() -> cpu_lock -> pidlock -> p_lock -> pool_barrier_lock
 *
 * Most static and global variables defined in this file are protected
 * by calling pool_lock().
 *
 * The operation that binds tasks and projects to pools is atomic.  That is,
 * either all processes in a given task or a project will be bound to a
 * new pool, or (in case of an error) they will be all left bound to the
 * old pool. Processes in a given task or a given project can only be bound to
 * different pools if they were rebound individually one by one as single
 * processes.  Threads or LWPs of the same process do not have pool bindings,
 * and are bound to the same resource sets associated with the resource pool
 * of that process.
 *
 * The following picture shows one possible pool configuration with three
 * pools and three processor sets.  Note that processor set "foo" is not
 * associated with any pools and therefore cannot have any processes
 * bound to it.  Two pools (default and foo) are associated with the
 * same processor set (default).  Also, note that processes in Task 2
 * are bound to different pools.
 *
 *
 *                                 Processor Sets
 *                              +---------+
 *             +--------------+========================>| default |
 *            a|          |             +---------+
 *            s|          |                 ||
 *            s|          |             +---------+
 *            o|          |             |   foo   |
 *            c|          |             +---------+
 *            i|          |                 ||
 *            a|          |             +---------+
 *            t|          |         +------>|   bar   |
 *            e|          |         |   +---------+
 *                    d|              |                 |
 *                     |              |                 |
 *         +---------+      +---------+      +---------+
 *     Pools   | default |======|   foo   |======|   bar   |
 *         +---------+      +---------+      +---------+
 *             @  @            @              @ @   @
 *                b|  |            |              | |   |
 *                o|  |            |              | |   |
 *                u|  +-----+      |      +-------+ |   +---+
 *                n|        |      |      |         |       |
 *            ....d|........|......|......|.........|.......|....
 *            :    |   ::   |      |      |    ::   |       |   :
 *            :  +---+ :: +---+  +---+  +---+  :: +---+   +---+ :
 *  Processes :  | p | :: | p |  | p |  | p |  :: | p |...| p | :
 *            :  +---+ :: +---+  +---+  +---+  :: +---+   +---+ :
 *            :........::......................::...............:
 *              Task 1            Task 2              Task N
 *                 |                 |                  |
 *                 |                 |                  |
 *                 |  +-----------+  |             +-----------+
 *                 +--| Project 1 |--+             | Project N |
 *                    +-----------+                +-----------+
 *
 * This is just an illustration of relationships between processes, tasks,
 * projects, pools, and processor sets. New types of resource sets will be
 * added in the future.
 */

pool_t      *pool_default;  /* default pool which always exists */
int     pool_count; /* number of pools created on this system */
int     pool_state; /* pools state -- enabled/disabled */
void        *pool_buf;  /* pre-commit snapshot of the pools state */
size_t      pool_bufsz; /* size of pool_buf */
static hrtime_t pool_pool_mod;  /* last modification time for pools */
static hrtime_t pool_sys_mod;   /* last modification time for system */
static nvlist_t *pool_sys_prop; /* system properties */
static id_space_t *pool_ids;    /* pool ID space */
static list_t   pool_list;  /* doubly-linked list of pools */
static kmutex_t     pool_mutex;     /* protects pool_busy_* */
static kcondvar_t   pool_busy_cv;       /* waiting for "pool_lock" */
static kthread_t    *pool_busy_thread;  /* thread holding "pool_lock" */
static kmutex_t     pool_barrier_lock;  /* synch. with pool_barrier_* */
static kcondvar_t   pool_barrier_cv;    /* synch. with pool_barrier_* */
static int      pool_barrier_count; /* synch. with pool_barrier_* */

/*
 * Boot-time pool initialization.
 */
void
pool_init(void)
{
    pool_ids = id_space_create("pool_ids", POOL_DEFAULT + 1, POOL_MAXID);

    /*
     * Initialize default pool.
     */
    pool_default = kmem_zalloc(sizeof (pool_t), KM_SLEEP);
    pool_default->pool_id = POOL_DEFAULT;
    list_create(&pool_list, sizeof (pool_t), offsetof(pool_t, pool_link));
    list_insert_head(&pool_list, pool_default);

    /*
     * Initialize plugins for resource sets.
     */
    pool_pset_init();
    pool_count = 1;
    p0.p_pool = pool_default;
    global_zone->zone_pool = pool_default;
    pool_default->pool_ref = 1;
}

/*
 * Synchronization routines.
 *
 * pool_lock is only called from syscall-level routines (processor_bind(),
 * pset_*(), and /dev/pool ioctls).  The pool "lock" may be held for long
 * periods of time, including across sleeping operations, so we allow its
 * acquisition to be interruptible.
 *
 * The current thread that owns the "lock" is stored in the variable
 * pool_busy_thread, both to let pool_lock_held() work and to aid debugging.
 */
void
pool_lock(void)
{
    mutex_enter(&pool_mutex);
    ASSERT(!pool_lock_held());
    while (pool_busy_thread != NULL)
        cv_wait(&pool_busy_cv, &pool_mutex);
    pool_busy_thread = curthread;
    mutex_exit(&pool_mutex);
}

int
pool_lock_intr(void)
{
    mutex_enter(&pool_mutex);
    ASSERT(!pool_lock_held());
    while (pool_busy_thread != NULL) {
        if (cv_wait_sig(&pool_busy_cv, &pool_mutex) == 0) {
            cv_signal(&pool_busy_cv);
            mutex_exit(&pool_mutex);
            return (1);
        }
    }
    pool_busy_thread = curthread;
    mutex_exit(&pool_mutex);
    return (0);
}

int
pool_lock_held(void)
{
    return (pool_busy_thread == curthread);
}

void
pool_unlock(void)
{
    mutex_enter(&pool_mutex);
    ASSERT(pool_lock_held());
    pool_busy_thread = NULL;
    cv_signal(&pool_busy_cv);
    mutex_exit(&pool_mutex);
}

/*
 * Routines allowing fork(), exec(), exit(), and lwp_create() to synchronize
 * with pool_do_bind().
 *
 * Calls to pool_barrier_enter() and pool_barrier_exit() must bracket all
 * operations which modify pool or pset associations.  They can be called
 * while the process is multi-threaded.  In the common case, when current
 * process is not being rebound (PBWAIT flag is not set), these functions
 * will be just incrementing and decrementing reference counts.
 */
void
pool_barrier_enter(void)
{
    proc_t *p = curproc;

    ASSERT(MUTEX_HELD(&p->p_lock));
    while (p->p_poolflag & PBWAIT)
        cv_wait(&p->p_poolcv, &p->p_lock);
    p->p_poolcnt++;
}

void
pool_barrier_exit(void)
{
    proc_t *p = curproc;

    ASSERT(MUTEX_HELD(&p->p_lock));
    ASSERT(p->p_poolcnt > 0);
    p->p_poolcnt--;
    if (p->p_poolflag & PBWAIT) {
        mutex_enter(&pool_barrier_lock);
        ASSERT(pool_barrier_count > 0);
        pool_barrier_count--;
        if (pool_barrier_count == 0)
            cv_signal(&pool_barrier_cv);
        mutex_exit(&pool_barrier_lock);
        while (p->p_poolflag & PBWAIT)
            cv_wait(&p->p_poolcv, &p->p_lock);
    }
}

/*
 * Enable pools facility.
 */
static int
pool_enable(void)
{
    int ret;

    ASSERT(pool_lock_held());
    ASSERT(pool_count == 1);

    ret = pool_pset_enable();
    if (ret != 0)
        return (ret);
    (void) nvlist_alloc(&pool_sys_prop, NV_UNIQUE_NAME, KM_SLEEP);
    (void) nvlist_add_string(pool_sys_prop, "system.name",
        "default");
    (void) nvlist_add_string(pool_sys_prop, "system.comment", "");
    (void) nvlist_add_int64(pool_sys_prop, "system.version", 1);
    (void) nvlist_add_byte(pool_sys_prop, "system.bind-default", 1);
    (void) nvlist_add_string(pool_sys_prop, "system.poold.objectives",
        "wt-load");

    (void) nvlist_alloc(&pool_default->pool_props,
        NV_UNIQUE_NAME, KM_SLEEP);
    (void) nvlist_add_string(pool_default->pool_props,
        "pool.name", "pool_default");
    (void) nvlist_add_string(pool_default->pool_props, "pool.comment", "");
    (void) nvlist_add_byte(pool_default->pool_props, "pool.default", 1);
    (void) nvlist_add_byte(pool_default->pool_props, "pool.active", 1);
    (void) nvlist_add_int64(pool_default->pool_props,
        "pool.importance", 1);
    (void) nvlist_add_int64(pool_default->pool_props, "pool.sys_id",
        pool_default->pool_id);

    pool_sys_mod = pool_pool_mod = gethrtime();

    return (ret);
}

/*
 * Disable pools facility.
 */
static int
pool_disable(void)
{
    int ret;

    ASSERT(pool_lock_held());

    if (pool_count > 1) /* must destroy all pools first */
        return (EBUSY);

    ret = pool_pset_disable();
    if (ret != 0)
        return (ret);
    if (pool_sys_prop != NULL) {
        nvlist_free(pool_sys_prop);
        pool_sys_prop = NULL;
    }
    if (pool_default->pool_props != NULL) {
        nvlist_free(pool_default->pool_props);
        pool_default->pool_props = NULL;
    }
    return (0);
}

pool_t *
pool_lookup_pool_by_name(char *name)
{
    pool_t *pool = pool_default;
    char *p;

    ASSERT(pool_lock_held());
    for (pool = list_head(&pool_list); pool;
        pool = list_next(&pool_list, pool)) {
        if (nvlist_lookup_string(pool->pool_props,
            "pool.name", &p) == 0 && strcmp(name, p) == 0)
            return (pool);
    }
    return (NULL);
}

pool_t *
pool_lookup_pool_by_id(poolid_t poolid)
{
    pool_t *pool = pool_default;

    ASSERT(pool_lock_held());
    for (pool = list_head(&pool_list); pool;
        pool = list_next(&pool_list, pool)) {
        if (pool->pool_id == poolid)
            return (pool);
    }
    return (NULL);
}

/*
 * Create new pool, associate it with default resource sets, and give
 * it a temporary name.
 */
static int
pool_pool_create(poolid_t *poolid)
{
    pool_t *pool;
    char pool_name[40];

    ASSERT(pool_lock_held());

    pool = kmem_zalloc(sizeof (pool_t), KM_SLEEP);
    pool->pool_id = *poolid = id_alloc(pool_ids);
    pool->pool_pset = pool_pset_default;
    pool_pset_default->pset_npools++;
    list_insert_tail(&pool_list, pool);
    (void) nvlist_alloc(&pool->pool_props, NV_UNIQUE_NAME, KM_SLEEP);
    (void) nvlist_add_int64(pool->pool_props, "pool.sys_id", pool->pool_id);
    (void) nvlist_add_byte(pool->pool_props, "pool.default", 0);
    pool_pool_mod = gethrtime();
    (void) snprintf(pool_name, sizeof (pool_name), "pool_%lld",
        pool_pool_mod);
    (void) nvlist_add_string(pool->pool_props, "pool.name", pool_name);
    pool_count++;
    return (0);
}

struct destroy_zone_arg {
    pool_t *old;
    pool_t *new;
};

/*
 * Update pool pointers for zones that are currently bound to pool "old"
 * to be bound to pool "new".
 */
static int
pool_destroy_zone_cb(zone_t *zone, void *arg)
{
    struct destroy_zone_arg *dza = arg;

    ASSERT(pool_lock_held());
    ASSERT(MUTEX_HELD(&cpu_lock));

    if (zone_pool_get(zone) == dza->old)
        zone_pool_set(zone, dza->new);
    return (0);
}

/*
 * Destroy specified pool, and rebind all processes in it
 * to the default pool.
 */
static int
pool_pool_destroy(poolid_t poolid)
{
    pool_t *pool;
    int ret;

    ASSERT(pool_lock_held());

    if (poolid == POOL_DEFAULT)
        return (EINVAL);
    if ((pool = pool_lookup_pool_by_id(poolid)) == NULL)
        return (ESRCH);
    ret = pool_do_bind(pool_default, P_POOLID, poolid, POOL_BIND_ALL);
    if (ret == 0) {
        struct destroy_zone_arg dzarg;

        dzarg.old = pool;
        dzarg.new = pool_default;
        mutex_enter(&cpu_lock);
        ret = zone_walk(pool_destroy_zone_cb, &dzarg);
        mutex_exit(&cpu_lock);
        ASSERT(ret == 0);
        ASSERT(pool->pool_ref == 0);
        (void) nvlist_free(pool->pool_props);
        id_free(pool_ids, pool->pool_id);
        pool->pool_pset->pset_npools--;
        list_remove(&pool_list, pool);
        pool_count--;
        pool_pool_mod = gethrtime();
        kmem_free(pool, sizeof (pool_t));
    }
    return (ret);
}

/*
 * Create new pool or resource set.
 */
int
pool_create(int class, int subclass, id_t *id)
{
    int ret;

    ASSERT(pool_lock_held());
    if (pool_state == POOL_DISABLED)
        return (ENOTACTIVE);
    switch (class) {
    case PEC_POOL:
        ret = pool_pool_create((poolid_t *)id);
        break;
    case PEC_RES_COMP:
        switch (subclass) {
        case PREC_PSET:
            ret = pool_pset_create((psetid_t *)id);
            break;
        default:
            ret = EINVAL;
        }
        break;
    case PEC_RES_AGG:
        ret = ENOTSUP;
        break;
    default:
        ret = EINVAL;
    }
    return (ret);
}

/*
 * Destroy an existing pool or resource set.
 */
int
pool_destroy(int class, int subclass, id_t id)
{
    int ret;

    ASSERT(pool_lock_held());
    if (pool_state == POOL_DISABLED)
        return (ENOTACTIVE);
    switch (class) {
    case PEC_POOL:
        ret = pool_pool_destroy((poolid_t)id);
        break;
    case PEC_RES_COMP:
        switch (subclass) {
        case PREC_PSET:
            ret = pool_pset_destroy((psetid_t)id);
            break;
        default:
            ret = EINVAL;
        }
        break;
    case PEC_RES_AGG:
        ret = ENOTSUP;
        break;
    default:
        ret = EINVAL;
    }
    return (ret);
}

/*
 * Enable or disable pools.
 */
int
pool_status(int status)
{
    int ret = 0;

    ASSERT(pool_lock_held());

    if (pool_state == status)
        return (0);
    switch (status) {
    case POOL_ENABLED:
        ret = pool_enable();
        if (ret != 0)
            return (ret);
        pool_state = POOL_ENABLED;
        break;
    case POOL_DISABLED:
        ret = pool_disable();
        if (ret != 0)
            return (ret);
        pool_state = POOL_DISABLED;
        break;
    default:
        ret = EINVAL;
    }
    return (ret);
}

/*
 * Associate pool with resource set.
 */
int
pool_assoc(poolid_t poolid, int idtype, id_t id)
{
    int ret;

    ASSERT(pool_lock_held());
    if (pool_state == POOL_DISABLED)
        return (ENOTACTIVE);
    switch (idtype) {
    case PREC_PSET:
        ret = pool_pset_assoc(poolid, (psetid_t)id);
        break;
    default:
        ret = EINVAL;
    }
    if (ret == 0)
        pool_pool_mod = gethrtime();
    return (ret);
}

/*
 * Disassociate resource set from pool.
 */
int
pool_dissoc(poolid_t poolid, int idtype)
{
    int ret;

    ASSERT(pool_lock_held());
    if (pool_state == POOL_DISABLED)
        return (ENOTACTIVE);
    switch (idtype) {
    case PREC_PSET:
        ret = pool_pset_assoc(poolid, PS_NONE);
        break;
    default:
        ret = EINVAL;
    }
    if (ret == 0)
        pool_pool_mod = gethrtime();
    return (ret);
}

/*
 * Transfer specified quantity of resources between resource sets.
 */
/*ARGSUSED*/
int
pool_transfer(int type, id_t src, id_t dst, uint64_t qty)
{
    int ret = EINVAL;
    return (ret);
}

/*
 * Transfer resources specified by their IDs between resource sets.
 */
int
pool_xtransfer(int type, id_t src, id_t dst, uint_t size, id_t *ids)
{
    int ret;

    ASSERT(pool_lock_held());
    if (pool_state == POOL_DISABLED)
        return (ENOTACTIVE);
    switch (type) {
    case PREC_PSET:
        ret = pool_pset_xtransfer((psetid_t)src, (psetid_t)dst,
            size, ids);
        break;
    default:
        ret = EINVAL;
    }
    return (ret);
}

/*
 * Bind processes to pools.
 */
int
pool_bind(poolid_t poolid, idtype_t idtype, id_t id)
{
    pool_t *pool;

    ASSERT(pool_lock_held());

    if (pool_state == POOL_DISABLED)
        return (ENOTACTIVE);
    if ((pool = pool_lookup_pool_by_id(poolid)) == NULL)
        return (ESRCH);

    switch (idtype) {
    case P_PID:
    case P_TASKID:
    case P_PROJID:
    case P_ZONEID:
        break;
    default:
        return (EINVAL);
    }
    return (pool_do_bind(pool, idtype, id, POOL_BIND_ALL));
}

/*
 * Query pool binding of the specifed process.
 */
int
pool_query_binding(idtype_t idtype, id_t id, id_t *poolid)
{
    proc_t *p;

    if (idtype != P_PID)
        return (ENOTSUP);
    if (id == P_MYID)
        id = curproc->p_pid;

    ASSERT(pool_lock_held());

    mutex_enter(&pidlock);
    if ((p = prfind((pid_t)id)) == NULL) {
        mutex_exit(&pidlock);
        return (ESRCH);
    }
    mutex_enter(&p->p_lock);
    /*
     * In local zones, lie about pool bindings of processes from
     * the global zone.
     */
    if (!INGLOBALZONE(curproc) && INGLOBALZONE(p)) {
        pool_t *pool;

        pool = zone_pool_get(curproc->p_zone);
        *poolid = pool->pool_id;
    } else {
        *poolid = p->p_pool->pool_id;
    }
    mutex_exit(&p->p_lock);
    mutex_exit(&pidlock);
    return (0);
}

static ea_object_t *
pool_system_pack(void)
{
    ea_object_t *eo_system;
    size_t bufsz = 0;
    char *buf = NULL;

    ASSERT(pool_lock_held());

    eo_system = ea_alloc_group(EXT_GROUP | EXC_LOCAL | EXD_GROUP_SYSTEM);
    (void) ea_attach_item(eo_system, &pool_sys_mod, sizeof (hrtime_t),
        EXC_LOCAL | EXD_SYSTEM_TSTAMP | EXT_UINT64);
    if (INGLOBALZONE(curproc))
        (void) ea_attach_item(eo_system, &pool_pool_mod,
            sizeof (hrtime_t),
            EXC_LOCAL | EXD_POOL_TSTAMP | EXT_UINT64);
    else
        (void) ea_attach_item(eo_system,
            &curproc->p_zone->zone_pool_mod,
            sizeof (hrtime_t),
            EXC_LOCAL | EXD_POOL_TSTAMP | EXT_UINT64);
    (void) ea_attach_item(eo_system, &pool_pset_mod, sizeof (hrtime_t),
        EXC_LOCAL | EXD_PSET_TSTAMP | EXT_UINT64);
    (void) ea_attach_item(eo_system, &pool_cpu_mod, sizeof (hrtime_t),
        EXC_LOCAL | EXD_CPU_TSTAMP | EXT_UINT64);
    (void) nvlist_pack(pool_sys_prop, &buf, &bufsz, NV_ENCODE_NATIVE, 0);
    (void) ea_attach_item(eo_system, buf, bufsz,
        EXC_LOCAL | EXD_SYSTEM_PROP | EXT_RAW);
    kmem_free(buf, bufsz);
    return (eo_system);
}

/*
 * Pack information about pools and attach it to specified exacct group.
 */
static int
pool_pool_pack(ea_object_t *eo_system)
{
    ea_object_t *eo_pool;
    pool_t *pool;
    size_t bufsz;
    char *buf;
    pool_t *myzonepool;

    ASSERT(pool_lock_held());
    myzonepool = zone_pool_get(curproc->p_zone);
    for (pool = list_head(&pool_list); pool;
        pool = list_next(&pool_list, pool)) {
        if (!INGLOBALZONE(curproc) && myzonepool != pool)
            continue;
        bufsz = 0;
        buf = NULL;
        eo_pool = ea_alloc_group(EXT_GROUP |
            EXC_LOCAL | EXD_GROUP_POOL);
        (void) ea_attach_item(eo_pool, &pool->pool_id, sizeof (id_t),
            EXC_LOCAL | EXD_POOL_POOLID | EXT_UINT32);
        (void) ea_attach_item(eo_pool, &pool->pool_pset->pset_id,
            sizeof (id_t), EXC_LOCAL | EXD_POOL_PSETID | EXT_UINT32);
        (void) nvlist_pack(pool->pool_props, &buf, &bufsz,
            NV_ENCODE_NATIVE, 0);
        (void) ea_attach_item(eo_pool, buf, bufsz,
            EXC_LOCAL | EXD_POOL_PROP | EXT_RAW);
        kmem_free(buf, bufsz);
        (void) ea_attach_to_group(eo_system, eo_pool);
    }
    return (0);
}

/*
 * Pack the whole pool configuration in the specified buffer.
 */
int
pool_pack_conf(void *kbuf, size_t kbufsz, size_t *asize)
{
    ea_object_t *eo_system;
    size_t ksize;
    int ret = 0;

    ASSERT(pool_lock_held());

    eo_system = pool_system_pack();     /* 1. pack system */
    (void) pool_pool_pack(eo_system);   /* 2. pack all pools */
    (void) pool_pset_pack(eo_system);   /* 3. pack all psets */
    ksize = ea_pack_object(eo_system, NULL, 0);
    if (kbuf == NULL || kbufsz == 0)
        *asize = ksize;
    else if (ksize > kbufsz)
        ret = ENOMEM;
    else
        *asize = ea_pack_object(eo_system, kbuf, kbufsz);
    ea_free_object(eo_system, EUP_ALLOC);
    return (ret);
}

/*
 * Start/end the commit transaction.  If commit transaction is currently
 * in progress, then all POOL_QUERY ioctls will return pools configuration
 * at the beginning of transaction.
 */
int
pool_commit(int state)
{
    ea_object_t *eo_system;
    int ret = 0;

    ASSERT(pool_lock_held());

    if (pool_state == POOL_DISABLED)
        return (ENOTACTIVE);
    switch (state) {
    case 1:
        /*
         * Beginning commit transation.
         */
        if (pool_buf != NULL)       /* transaction in progress */
            return (EBUSY);
        eo_system = pool_system_pack();     /* 1. pack system */
        (void) pool_pool_pack(eo_system);   /* 2. pack all pools */
        (void) pool_pset_pack(eo_system);   /* 3. pack all psets */
        pool_bufsz = ea_pack_object(eo_system, NULL, 0);
        pool_buf = kmem_alloc(pool_bufsz, KM_SLEEP);
        pool_bufsz = ea_pack_object(eo_system, pool_buf, pool_bufsz);
        ea_free_object(eo_system, EUP_ALLOC);
        break;
    case 0:
        /*
         * Finishing commit transaction.
         */
        if (pool_buf != NULL) {
            kmem_free(pool_buf, pool_bufsz);
            pool_buf = NULL;
            pool_bufsz = 0;
        }
        break;
    default:
        ret = EINVAL;
    }
    return (ret);
}

/*
 * Check is the specified property is special
 */
static pool_property_t *
pool_property_find(char *name, pool_property_t *list)
{
    pool_property_t *prop;

    for (prop = list; prop->pp_name != NULL; prop++)
        if (strcmp(prop->pp_name, name) == 0)
            return (prop);
    return (NULL);
}

static pool_property_t pool_prop_sys[] = {
    { "system.name",        DATA_TYPE_STRING,   PP_RDWR },
    { "system.comment",     DATA_TYPE_STRING,   PP_RDWR },
    { "system.version",     DATA_TYPE_UINT64,   PP_READ },
    { "system.bind-default",    DATA_TYPE_BYTE,     PP_RDWR },
    { "system.allocate-method", DATA_TYPE_STRING,
        PP_RDWR | PP_OPTIONAL },
    { "system.poold.log-level", DATA_TYPE_STRING,
        PP_RDWR | PP_OPTIONAL },
    { "system.poold.log-location",  DATA_TYPE_STRING,
        PP_RDWR | PP_OPTIONAL },
    { "system.poold.monitor-interval",  DATA_TYPE_UINT64,
        PP_RDWR | PP_OPTIONAL },
    { "system.poold.history-file",  DATA_TYPE_STRING,
        PP_RDWR | PP_OPTIONAL },
    { "system.poold.objectives",    DATA_TYPE_STRING,
        PP_RDWR | PP_OPTIONAL },
    { NULL,             0,          0 }
};

static pool_property_t pool_prop_pool[] = {
    { "pool.sys_id",        DATA_TYPE_UINT64,   PP_READ },
    { "pool.name",          DATA_TYPE_STRING,   PP_RDWR },
    { "pool.default",       DATA_TYPE_BYTE,     PP_READ },
    { "pool.active",        DATA_TYPE_BYTE,     PP_RDWR },
    { "pool.importance",        DATA_TYPE_INT64,    PP_RDWR },
    { "pool.comment",       DATA_TYPE_STRING,   PP_RDWR },
    { "pool.scheduler",     DATA_TYPE_STRING,
        PP_RDWR | PP_OPTIONAL },
    { NULL,             0,          0 }
};

/*
 * Common routine to put new property on the specified list
 */
int
pool_propput_common(nvlist_t *nvlist, nvpair_t *pair, pool_property_t *props)
{
    pool_property_t *prop;

    if ((prop = pool_property_find(nvpair_name(pair), props)) != NULL) {
        /*
         * No read-only properties or properties with bad types
         */
        if (!(prop->pp_perm & PP_WRITE) ||
            prop->pp_type != nvpair_type(pair))
            return (EINVAL);
    }
    return (nvlist_add_nvpair(nvlist, pair));
}

/*
 * Common routine to remove property from the given list
 */
int
pool_proprm_common(nvlist_t *nvlist, char *name, pool_property_t *props)
{
    pool_property_t *prop;

    if ((prop = pool_property_find(name, props)) != NULL) {
        if (!(prop->pp_perm & PP_OPTIONAL))
            return (EINVAL);
    }
    return (nvlist_remove_all(nvlist, name));
}

static int
pool_system_propput(nvpair_t *pair)
{
    int ret;

    ASSERT(pool_lock_held());
    ret = pool_propput_common(pool_sys_prop, pair, pool_prop_sys);
    if (ret == 0)
        pool_sys_mod = gethrtime();
    return (ret);
}

static int
pool_system_proprm(char *name)
{
    int ret;

    ASSERT(pool_lock_held());
    ret = pool_proprm_common(pool_sys_prop, name, pool_prop_sys);
    if (ret == 0)
        pool_sys_mod = gethrtime();
    return (ret);
}

static int
pool_pool_propput(poolid_t poolid, nvpair_t *pair)
{
    pool_t *pool;
    int ret;

    ASSERT(pool_lock_held());
    if ((pool = pool_lookup_pool_by_id(poolid)) == NULL)
        return (ESRCH);
    ret = pool_propput_common(pool->pool_props, pair, pool_prop_pool);
    if (ret == 0)
        pool_pool_mod = gethrtime();
    return (ret);
}

static int
pool_pool_proprm(poolid_t poolid, char *name)
{
    int ret;
    pool_t *pool;

    ASSERT(pool_lock_held());
    if ((pool = pool_lookup_pool_by_id(poolid)) == NULL)
        return (ESRCH);
    ret = pool_proprm_common(pool->pool_props, name, pool_prop_pool);
    if (ret == 0)
        pool_pool_mod = gethrtime();
    return (ret);
}

int
pool_propput(int class, int subclass, id_t id, nvpair_t *pair)
{
    int ret;

    ASSERT(pool_lock_held());
    if (pool_state == POOL_DISABLED)
        return (ENOTACTIVE);
    switch (class) {
    case PEC_SYSTEM:
        ret = pool_system_propput(pair);
        break;
    case PEC_POOL:
        ret = pool_pool_propput((poolid_t)id, pair);
        break;
    case PEC_RES_COMP:
        switch (subclass) {
        case PREC_PSET:
            ret = pool_pset_propput((psetid_t)id, pair);
            break;
        default:
            ret = EINVAL;
        }
        break;
    case PEC_RES_AGG:
        ret = ENOTSUP;
        break;
    case PEC_COMP:
        switch (subclass) {
        case PCEC_CPU:
            ret = pool_cpu_propput((processorid_t)id, pair);
            break;
        default:
            ret = EINVAL;
        }
        break;
    default:
        ret = EINVAL;
    }
    return (ret);
}

int
pool_proprm(int class, int subclass, id_t id, char *name)
{
    int ret;

    ASSERT(pool_lock_held());
    if (pool_state == POOL_DISABLED)
        return (ENOTACTIVE);
    switch (class) {
    case PEC_SYSTEM:
        ret = pool_system_proprm(name);
        break;
    case PEC_POOL:
        ret = pool_pool_proprm((poolid_t)id, name);
        break;
    case PEC_RES_COMP:
        switch (subclass) {
        case PREC_PSET:
            ret = pool_pset_proprm((psetid_t)id, name);
            break;
        default:
            ret = EINVAL;
        }
        break;
    case PEC_RES_AGG:
        ret = ENOTSUP;
        break;
    case PEC_COMP:
        switch (subclass) {
        case PCEC_CPU:
            ret = pool_cpu_proprm((processorid_t)id, name);
            break;
        default:
            ret = EINVAL;
        }
        break;
    default:
        ret = EINVAL;
    }
    return (ret);
}

int
pool_propget(char *name, int class, int subclass, id_t id, nvlist_t **nvlp)
{
    int ret;
    nvlist_t *nvl;

    ASSERT(pool_lock_held());
    if (pool_state == POOL_DISABLED)
        return (ENOTACTIVE);

    (void) nvlist_alloc(&nvl, NV_UNIQUE_NAME, KM_SLEEP);

    switch (class) {
    case PEC_SYSTEM:
    case PEC_POOL:
        ret = EINVAL;
        break;
    case PEC_RES_COMP:
        switch (subclass) {
        case PREC_PSET:
            ret = pool_pset_propget((psetid_t)id, name, nvl);
            break;
        default:
            ret = EINVAL;
        }
        break;
    case PEC_RES_AGG:
        ret = ENOTSUP;
        break;
    case PEC_COMP:
        switch (subclass) {
        case PCEC_CPU:
            ret = pool_cpu_propget((processorid_t)id, name, nvl);
            break;
        default:
            ret = EINVAL;
        }
        break;
    default:
        ret = EINVAL;
    }
    if (ret == 0)
        *nvlp = nvl;
    else
        nvlist_free(nvl);
    return (ret);
}

/*
 * pool_bind_wake and pool_bind_wakeall are helper functions to undo PBWAITs
 * in case of failure in pool_do_bind().
 */
static void
pool_bind_wake(proc_t *p)
{
    ASSERT(pool_lock_held());

    mutex_enter(&p->p_lock);
    ASSERT(p->p_poolflag & PBWAIT);
    if (p->p_poolcnt > 0) {
        mutex_enter(&pool_barrier_lock);
        pool_barrier_count -= p->p_poolcnt;
        mutex_exit(&pool_barrier_lock);
    }
    p->p_poolflag &= ~PBWAIT;
    cv_signal(&p->p_poolcv);
    mutex_exit(&p->p_lock);
}

static void
pool_bind_wakeall(proc_t **procs)
{
    proc_t *p, **pp;

    ASSERT(pool_lock_held());
    for (pp = procs; (p = *pp) != NULL; pp++)
        pool_bind_wake(p);
}

/*
 * Return the scheduling class for this pool, or
 *  POOL_CLASS_UNSET if not set
 *  POOL_CLASS_INVAL if set to an invalid class ID.
 */
id_t
pool_get_class(pool_t *pool)
{
    char *name;
    id_t cid;

    ASSERT(pool_lock_held());

    if (nvlist_lookup_string(pool->pool_props, "pool.scheduler",
        &name) == 0) {
        if (getcidbyname(name, &cid) == 0)
            return (cid);
        else
            return (POOL_CLASS_INVAL);
    }
    return (POOL_CLASS_UNSET);
}

/*
 * Move process to the new scheduling class.
 */
static void
pool_change_class(proc_t *p, id_t cid)
{
    kthread_t *t;
    void *cldata;
    id_t oldcid;
    void **bufs;
    void **buf;
    int nlwp;
    int ret;
    int i;

    /*
     * Do not move kernel processes (such as zsched).
     */
    if (p->p_flag & SSYS)
        return;
    /*
     * This process is in the pool barrier, so it can't possibly be
     * adding new threads and we can use p_lwpcnt + p_zombcnt + 1
     * (for possible agent LWP which doesn't use pool barrier) as
     * our upper bound.
     */
    nlwp = p->p_lwpcnt + p->p_zombcnt + 1;

    /*
     * Pre-allocate scheduling class specific buffers before
     * grabbing p_lock.
     */
    bufs = kmem_zalloc(nlwp * sizeof (void *), KM_SLEEP);
    for (i = 0, buf = bufs; i < nlwp; i++, buf++) {
        ret = CL_ALLOC(buf, cid, KM_SLEEP);
        ASSERT(ret == 0);
    }

    /*
     * Move threads one by one to the new scheduling class.
     * This never fails because we have all the right
     * privileges here.
     */
    mutex_enter(&p->p_lock);
    ASSERT(p->p_poolflag & PBWAIT);
    buf = bufs;
    t = p->p_tlist;
    ASSERT(t != NULL);
    do {
        if (t->t_cid != cid) {
            oldcid = t->t_cid;
            cldata = t->t_cldata;
            ret = CL_ENTERCLASS(t, cid, NULL, NULL, *buf);
            ASSERT(ret == 0);
            CL_EXITCLASS(oldcid, cldata);
            schedctl_set_cidpri(t);
            *buf++ = NULL;
        }
    } while ((t = t->t_forw) != p->p_tlist);
    mutex_exit(&p->p_lock);
    /*
     * Free unused scheduling class specific buffers.
     */
    for (i = 0, buf = bufs; i < nlwp; i++, buf++) {
        if (*buf != NULL) {
            CL_FREE(cid, *buf);
            *buf = NULL;
        }
    }
    kmem_free(bufs, nlwp * sizeof (void *));
}

/*
 * The meat of the bind operation.  The steps in pool_do_bind are:
 *
 * 1) Set PBWAIT in the p_poolflag of any process of interest, and add all
 *    such processes to an array.  For any interesting process that has
 *    threads inside the pool barrier set, increment a counter by the
 *    count of such threads.  Once PBWAIT is set on a process, that process
 *    will not disappear.
 *
 * 2) Wait for the counter from step 2 to drop to zero.  Any process which
 *    calls pool_barrier_exit() and notices that PBWAIT has been set on it
 *    will decrement that counter before going to sleep, and the process
 *    calling pool_barrier_exit() which does the final decrement will wake us.
 *
 * 3) For each interesting process, perform a calculation on it to see if
 *    the bind will actually succeed.  This uses the following three
 *    resource-set-specific functions:
 *
 *    - int set_bind_start(procs, pool)
 *
 *      Determine whether the given array of processes can be bound to the
 *      resource set associated with the given pool.  If it can, take and hold
 *      any locks necessary to ensure that the operation will succeed, and
 *      make any necessary reservations in the target resource set.  If it
 *      can't, return failure with no reservations made and no new locks held.
 *
 *    - void set_bind_abort(procs, pool)
 *
 *      set_bind_start() has completed successfully, but another resource set's
 *      set_bind_start() has failed, and we haven't begun the bind yet.  Undo
 *      any reservations made and drop any locks acquired by our
 *      set_bind_start().
 *
 *    - void set_bind_finish(void)
 *
 *      The bind has completed successfully.  The processes have been released,
 *      and the reservation acquired in set_bind_start() has been depleted as
 *      the processes have finished their bindings.  Drop any locks acquired by
 *      set_bind_start().
 *
 * 4) If we've decided that we can proceed with the bind, iterate through
 *    the list of interesting processes, grab the necessary locks (which
 *    may differ per resource set), perform the bind, and ASSERT that it
 *    succeeds.  Once a process has been rebound, it can be awakened.
 *
 * The operations from step 4 must be kept in sync with anything which might
 * cause the bind operations (e.g., cpupart_bind_thread()) to fail, and
 * are thus located in the same source files as the associated bind operations.
 */
int
pool_do_bind(pool_t *pool, idtype_t idtype, id_t id, int flags)
{
    extern uint_t nproc;
    klwp_t *lwp = ttolwp(curthread);
    proc_t **pp, **procs;
    proc_t *prstart;
    int procs_count = 0;
    kproject_t *kpj;
    procset_t set;
    zone_t *zone;
    int procs_size;
    int rv = 0;
    proc_t *p;
    id_t cid = -1;

    ASSERT(pool_lock_held());

    if ((cid = pool_get_class(pool)) == POOL_CLASS_INVAL)
        return (EINVAL);

    if (idtype == P_ZONEID) {
        zone = zone_find_by_id(id);
        if (zone == NULL)
            return (ESRCH);
        if (zone_status_get(zone) > ZONE_IS_RUNNING) {
            zone_rele(zone);
            return (EBUSY);
        }
    }

    if (idtype == P_PROJID) {
        kpj = project_hold_by_id(id, global_zone, PROJECT_HOLD_FIND);
        if (kpj == NULL)
            return (ESRCH);
        mutex_enter(&kpj->kpj_poolbind);
    }

    if (idtype == P_PID) {
        /*
         * Fast-path for a single process case.
         */
        procs_size = 2; /* procs is NULL-terminated */
        procs = kmem_zalloc(procs_size * sizeof (proc_t *), KM_SLEEP);
        mutex_enter(&pidlock);
    } else {
        /*
         * We will need enough slots for proc_t pointers for as many as
         * twice the number of currently running processes (assuming
         * that each one could be in fork() creating a new child).
         */
        for (;;) {
            procs_size = nproc * 2;
            procs = kmem_zalloc(procs_size * sizeof (proc_t *),
                KM_SLEEP);
            mutex_enter(&pidlock);

            if (nproc * 2 <= procs_size)
                break;
            /*
             * If nproc has changed, try again.
             */
            mutex_exit(&pidlock);
            kmem_free(procs, procs_size * sizeof (proc_t *));
        }
    }

    if (id == P_MYID)
        id = getmyid(idtype);
    setprocset(&set, POP_AND, idtype, id, P_ALL, 0);

    /*
     * Do a first scan, and select target processes.
     */
    if (idtype == P_PID)
        prstart = prfind(id);
    else
        prstart = practive;
    for (p = prstart, pp = procs; p != NULL; p = p->p_next) {
        mutex_enter(&p->p_lock);
        /*
         * Skip processes that don't match our (id, idtype) set or
         * on the way of becoming zombies.  Skip kernel processes
         * from the global zone.
         */
        if (procinset(p, &set) == 0 ||
            p->p_poolflag & PEXITED ||
            ((p->p_flag & SSYS) && INGLOBALZONE(p))) {
            mutex_exit(&p->p_lock);
            continue;
        }
        if (!INGLOBALZONE(p)) {
            switch (idtype) {
            case P_PID:
            case P_TASKID:
                /*
                 * Can't bind processes or tasks
                 * in local zones to pools.
                 */
                mutex_exit(&p->p_lock);
                mutex_exit(&pidlock);
                pool_bind_wakeall(procs);
                rv = EINVAL;
                goto out;
            case P_PROJID:
                /*
                 * Only projects in the global
                 * zone can be rebound.
                 */
                mutex_exit(&p->p_lock);
                continue;
            case P_POOLID:
                /*
                 * When rebinding pools, processes can be
                 * in different zones.
                 */
                break;
            }
        }

        p->p_poolflag |= PBWAIT;
        /*
         * If some threads in this process are inside the pool
         * barrier, add them to pool_barrier_count, as we have
         * to wait for all of them to exit the barrier.
         */
        if (p->p_poolcnt > 0) {
            mutex_enter(&pool_barrier_lock);
            pool_barrier_count += p->p_poolcnt;
            mutex_exit(&pool_barrier_lock);
        }
        ASSERT(pp < &procs[procs_size]);
        *pp++ = p;
        procs_count++;
        mutex_exit(&p->p_lock);

        /*
         * We just found our process, so if we're only rebinding a
         * single process then get out of this loop.
         */
        if (idtype == P_PID)
            break;
    }
    *pp = NULL; /* cap off the end of the array */
    mutex_exit(&pidlock);

    /*
     * Wait for relevant processes to stop before they try to enter the
     * barrier or at the exit from the barrier.  Make sure that we do
     * not get stopped here while we're holding pool_lock.  If we were
     * requested to stop, or got a signal then return EAGAIN to let the
     * library know that it needs to retry.
     */
    mutex_enter(&pool_barrier_lock);
    lwp->lwp_nostop++;
    while (pool_barrier_count > 0) {
        (void) cv_wait_sig(&pool_barrier_cv, &pool_barrier_lock);
        if (pool_barrier_count > 0) {
            /*
             * We either got a signal or were requested to
             * stop by /proc.  Bail out with EAGAIN.  If we were
             * requested to stop, we'll stop in post_syscall()
             * on our way back to userland.
             */
            mutex_exit(&pool_barrier_lock);
            pool_bind_wakeall(procs);
            lwp->lwp_nostop--;
            rv = EAGAIN;
            goto out;
        }
    }
    lwp->lwp_nostop--;
    mutex_exit(&pool_barrier_lock);

    if (idtype == P_PID) {
        if ((p = *procs) == NULL)
            goto skip;
        mutex_enter(&p->p_lock);
        /* Drop the process if it is exiting */
        if (p->p_poolflag & PEXITED) {
            mutex_exit(&p->p_lock);
            pool_bind_wake(p);
            procs_count--;
        } else
            mutex_exit(&p->p_lock);
        goto skip;
    }

    /*
     * Do another run, and drop processes that were inside the barrier
     * in exit(), but when they have dropped to pool_barrier_exit
     * they have become of no interest to us.  Pick up child processes that
     * were created by fork() but didn't exist during our first scan.
     * Their parents are now stopped at pool_barrier_exit in cfork().
     */
    mutex_enter(&pidlock);
    for (pp = procs; (p = *pp) != NULL; pp++) {
        mutex_enter(&p->p_lock);
        if (p->p_poolflag & PEXITED) {
            ASSERT(p->p_lwpcnt == 0);
            mutex_exit(&p->p_lock);
            pool_bind_wake(p);
            /* flip w/last non-NULL slot */
            *pp = procs[procs_count - 1];
            procs[procs_count - 1] = NULL;
            procs_count--;
            pp--;           /* try this slot again */
            continue;
        } else
            mutex_exit(&p->p_lock);
        /*
         * Look at the child and check if it should be rebound also.
         * We're holding pidlock, so it is safe to reference p_child.
         */
        if ((p = p->p_child) == NULL)
            continue;

        mutex_enter(&p->p_lock);

        /*
         * Skip system processes and make sure that the child is in
         * the same task/project/pool/zone as the parent.
         */
        if ((!INGLOBALZONE(p) && idtype != P_ZONEID &&
            idtype != P_POOLID) || p->p_flag & SSYS) {
            mutex_exit(&p->p_lock);
            continue;
        }

        /*
         * If the child process has been already created by fork(), has
         * not exited, and has not been added to the list already,
         * then add it now.  We will hit this process again (since we
         * stick it at the end of the procs list) but it will ignored
         * because it will have the PBWAIT flag set.
         */
        if (procinset(p, &set) &&
            !(p->p_poolflag & PEXITED) &&
            !(p->p_poolflag & PBWAIT)) {
            ASSERT(p->p_child == NULL); /* no child of a child */
            procs[procs_count] = p;
            procs[procs_count + 1] = NULL;
            procs_count++;
            p->p_poolflag |= PBWAIT;
        }
        mutex_exit(&p->p_lock);
    }
    mutex_exit(&pidlock);
skip:
    /*
     * If there's no processes to rebind then return ESRCH, unless
     * we're associating a pool with new resource set, destroying it,
     * or binding a zone to a pool.
     */
    if (procs_count == 0) {
        if (idtype == P_POOLID || idtype == P_ZONEID)
            rv = 0;
        else
            rv = ESRCH;
        goto out;
    }

#ifdef DEBUG
    /*
     * All processes in the array should have PBWAIT set, and none
     * should be in the critical section. Thus, although p_poolflag
     * and p_poolcnt are protected by p_lock, their ASSERTions below
     * should be stable without it. procinset(), however, ASSERTs that
     * the p_lock is held upon entry.
     */
    for (pp = procs; (p = *pp) != NULL; pp++) {
        int in_set;

        mutex_enter(&p->p_lock);
        in_set = procinset(p, &set);
        mutex_exit(&p->p_lock);

        ASSERT(in_set);
        ASSERT(p->p_poolflag & PBWAIT);
        ASSERT(p->p_poolcnt == 0);
    }
#endif

    /*
     * Do the check if processor set rebinding is going to succeed or not.
     */
    if ((flags & POOL_BIND_PSET) &&
        (rv = pset_bind_start(procs, pool)) != 0) {
        pool_bind_wakeall(procs);
        goto out;
    }

    /*
     * At this point, all bind operations should succeed.
     */
    for (pp = procs; (p = *pp) != NULL; pp++) {
        if (flags & POOL_BIND_PSET) {
            psetid_t psetid = pool->pool_pset->pset_id;
            void *zonebuf;
            void *projbuf;

            /*
             * Pre-allocate one buffer for FSS (per-project
             * buffer for a new pset) in case if this is the
             * first thread from its current project getting
             * bound to this processor set.
             */
            projbuf = fss_allocbuf(FSS_ONE_BUF, FSS_ALLOC_PROJ);
            zonebuf = fss_allocbuf(FSS_ONE_BUF, FSS_ALLOC_ZONE);

            mutex_enter(&pidlock);
            mutex_enter(&p->p_lock);
            pool_pset_bind(p, psetid, projbuf, zonebuf);
            mutex_exit(&p->p_lock);
            mutex_exit(&pidlock);
            /*
             * Free buffers pre-allocated above if it
             * wasn't actually used.
             */
            fss_freebuf(projbuf, FSS_ALLOC_PROJ);
            fss_freebuf(zonebuf, FSS_ALLOC_ZONE);
        }
        /*
         * Now let's change the scheduling class of this
         * process if our target pool has it defined.
         */
        if (cid != POOL_CLASS_UNSET)
            pool_change_class(p, cid);

        /*
         * It is safe to reference p_pool here without holding
         * p_lock because it cannot change underneath of us.
         * We're holding pool_lock here, so nobody else can be
         * moving this process between pools.  If process "p"
         * would be exiting, we're guaranteed that it would be blocked
         * at pool_barrier_enter() in exit().  Otherwise, it would've
         * been skipped by one of our scans of the practive list
         * as a process with PEXITED flag set.
         */
        if (p->p_pool != pool) {
            ASSERT(p->p_pool->pool_ref > 0);
            atomic_add_32(&p->p_pool->pool_ref, -1);
            p->p_pool = pool;
            atomic_add_32(&p->p_pool->pool_ref, 1);
        }
        /*
         * Okay, we've tortured this guy enough.
         * Let this poor process go now.
         */
        pool_bind_wake(p);
    }
    if (flags & POOL_BIND_PSET)
        pset_bind_finish();

out:    switch (idtype) {
    case P_PROJID:
        ASSERT(kpj != NULL);
        mutex_exit(&kpj->kpj_poolbind);
        project_rele(kpj);
        break;
    case P_ZONEID:
        if (rv == 0) {
            mutex_enter(&cpu_lock);
            zone_pool_set(zone, pool);
            mutex_exit(&cpu_lock);
        }
        zone->zone_pool_mod = gethrtime();
        zone_rele(zone);
        break;
    }

    kmem_free(procs, procs_size * sizeof (proc_t *));
    ASSERT(pool_barrier_count == 0);
    return (rv);
}