C++ P2ROUNDUP函数代码示例

/*
 * Clock tick initialization is done in two phases:
 *
 * 1. Before clock_init() is called, clock_tick_init_pre() is called to set
 *    up single-threading so the clock() can begin to do its job.
 *
 * 2. After the slave CPUs are initialized at boot time, we know the number
 *    of CPUs. clock_tick_init_post() is called to set up multi-threading if
 *    required.
 */
void
clock_tick_init_pre(void)
{
	clock_tick_cpu_t	*ctp;
	int			i, n;
	clock_tick_set_t	*csp;
	uintptr_t		buf;
	size_t			size;

	clock_tick_single_threaded = 1;

	size = P2ROUNDUP(sizeof (clock_tick_cpu_t), CLOCK_TICK_ALIGN);
	buf = (uintptr_t)kmem_zalloc(size * NCPU + CLOCK_TICK_ALIGN, KM_SLEEP);
	buf = P2ROUNDUP(buf, CLOCK_TICK_ALIGN);

	/*
	 * Perform initialization in case multi-threading is chosen later.
	 */
	if (&create_softint != NULL) {
		clock_tick_intr = create_softint(LOCK_LEVEL,
		    clock_tick_execute, (caddr_t)NULL);
	}
	for (i = 0; i < NCPU; i++, buf += size) {
		ctp = (clock_tick_cpu_t *)buf;
		clock_tick_cpu[i] = ctp;
		mutex_init(&ctp->ct_lock, NULL, MUTEX_DEFAULT, NULL);
		if (&create_softint != NULL) {
			ctp->ct_intr = clock_tick_intr;
		}
		ctp->ct_pending = 0;
	}

	mutex_init(&clock_tick_lock, NULL, MUTEX_DEFAULT, NULL);

	/*
	 * Compute clock_tick_ncpus here. We need it to compute the
	 * maximum number of tick sets we need to support.
	 */
	ASSERT(clock_tick_ncpus >= 0);
	if (clock_tick_ncpus == 0)
		clock_tick_ncpus = CLOCK_TICK_NCPUS;
	if (clock_tick_ncpus > max_ncpus)
		clock_tick_ncpus = max_ncpus;

	/*
	 * Allocate and initialize the tick sets.
	 */
	n = (max_ncpus + clock_tick_ncpus - 1)/clock_tick_ncpus;
	clock_tick_set = kmem_zalloc(sizeof (clock_tick_set_t) * n, KM_SLEEP);
	for (i = 0; i < n; i++) {
		csp = &clock_tick_set[i];
		csp->ct_start = i * clock_tick_ncpus;
		csp->ct_scan = csp->ct_start;
		csp->ct_end = csp->ct_start;
	}
}

/*
 * Propagate the bootblock on the source disk to the destination disk and
 * version it with 'updt_str' in the process. Since we cannot trust any data
 * on the attaching disk, we do not perform any specific check on a potential
 * target extended information structure and we just blindly update.
 */
static int
propagate_bootblock(ig_data_t *source, ig_data_t *target, char *updt_str)
{
	ig_device_t	*src_device = &source->device;
	ig_device_t	*dest_device = &target->device;
	ig_stage2_t	*src_stage2 = &source->stage2;
	ig_stage2_t	*dest_stage2 = &target->stage2;
	uint32_t	buf_size;
	int		retval;

	assert(source != NULL);
	assert(target != NULL);

	/* read in stage1 from the source disk. */
	if (read_stage1_from_disk(src_device->part_fd, target->stage1_buf)
	    != BC_SUCCESS)
		return (BC_ERROR);

	/* Prepare target stage2 for commit_to_disk. */
	cleanup_stage2(dest_stage2);

	if (updt_str != NULL)
		do_version = B_TRUE;
	else
		do_version = B_FALSE;

	buf_size = src_stage2->file_size + SECTOR_SIZE;

	dest_stage2->buf_size = P2ROUNDUP(buf_size, SECTOR_SIZE);
	dest_stage2->buf = malloc(dest_stage2->buf_size);
	if (dest_stage2->buf == NULL) {
		perror(gettext("Memory allocation failed"));
		return (BC_ERROR);
	}
	dest_stage2->file = dest_stage2->buf;
	dest_stage2->file_size = src_stage2->file_size;
	memcpy(dest_stage2->file, src_stage2->file, dest_stage2->file_size);
	dest_stage2->extra = dest_stage2->buf +
	    P2ROUNDUP(dest_stage2->file_size, 8);

	/* If we get down here we do have a mboot structure. */
	assert(src_stage2->mboot);

	dest_stage2->mboot_off = src_stage2->mboot_off;
	dest_stage2->mboot = (multiboot_header_t *)(dest_stage2->buf +
	    dest_stage2->mboot_off);

	(void) fprintf(stdout, gettext("Propagating %s stage1/stage2 to %s\n"),
	    src_device->path, dest_device->path);
	retval = commit_to_disk(target, updt_str);

	return (retval);
}

/*
 * _sbrk_grow_aligned() aligns the old break to a low_align boundry,
 * adds min_size, aligns to a high_align boundry, and calls _brk_unlocked()
 * to set the new break.  The low_aligned-aligned value is returned, and
 * the actual space allocated is returned through actual_size.
 *
 * Unlike sbrk(2), _sbrk_grow_aligned takes an unsigned size, and does
 * not allow shrinking the heap.
 */
void *
_sbrk_grow_aligned(size_t min_size, size_t low_align, size_t high_align,
    size_t *actual_size)
{
	uintptr_t old_brk;
	uintptr_t ret_brk;
	uintptr_t high_brk;
	uintptr_t new_brk;
	int brk_result;

	if (!primary_link_map) {
		errno = ENOTSUP;
		return ((void *)-1);
	}
	if ((low_align & (low_align - 1)) != 0 ||
	    (high_align & (high_align - 1)) != 0) {
		errno = EINVAL;
		return ((void *)-1);
	}
	low_align = MAX(low_align, ALIGNSZ);
	high_align = MAX(high_align, ALIGNSZ);

	lmutex_lock(&__sbrk_lock);

	old_brk = (uintptr_t)BRKALIGN(_nd);
	ret_brk = P2ROUNDUP(old_brk, low_align);
	high_brk = ret_brk + min_size;
	new_brk = P2ROUNDUP(high_brk, high_align);

	/*
	 * Check for overflow
	 */
	if (ret_brk < old_brk || high_brk < ret_brk || new_brk < high_brk) {
		lmutex_unlock(&__sbrk_lock);
		errno = ENOMEM;
		return ((void *)-1);
	}

	if ((brk_result = _brk_unlocked((void *)new_brk)) == 0)
		_nd = (void *)new_brk;
	lmutex_unlock(&__sbrk_lock);

	if (brk_result != 0)
		return ((void *)-1);

	if (actual_size != NULL)
		*actual_size = (new_brk - ret_brk);
	return ((void *)ret_brk);
}

static void
sa_attr_iter(objset_t *os, sa_hdr_phys_t *hdr, dmu_object_type_t type,
    sa_iterfunc_t func, sa_lot_t *tab, void *userp)
{
	void *data_start;
	sa_lot_t *tb = tab;
	sa_lot_t search;
	avl_index_t loc;
	sa_os_t *sa = os->os_sa;
	int i;
	uint16_t *length_start = NULL;
	uint8_t length_idx = 0;

	if (tab == NULL) {
		search.lot_num = SA_LAYOUT_NUM(hdr, type);
		tb = avl_find(&sa->sa_layout_num_tree, &search, &loc);
		ASSERT(tb);
	}

	if (IS_SA_BONUSTYPE(type)) {
		data_start = (void *)P2ROUNDUP(((uintptr_t)hdr +
		    offsetof(sa_hdr_phys_t, sa_lengths) +
		    (sizeof (uint16_t) * tb->lot_var_sizes)), 8);
		length_start = hdr->sa_lengths;
	} else {
		data_start = hdr;
	}

	for (i = 0; i != tb->lot_attr_count; i++) {
		int attr_length, reg_length;
		uint8_t idx_len;

		reg_length = sa->sa_attr_table[tb->lot_attrs[i]].sa_length;
		if (reg_length) {
			attr_length = reg_length;
			idx_len = 0;
		} else {
			attr_length = length_start[length_idx];
			idx_len = length_idx++;
		}

		func(hdr, data_start, tb->lot_attrs[i], attr_length,
		    idx_len, reg_length == 0 ? B_TRUE : B_FALSE, userp);

		data_start = (void *)P2ROUNDUP(((uintptr_t)data_start +
		    attr_length), 8);
	}
}

static void
fmd_ckpt_resv_buf(fmd_buf_t *bp, fmd_ckpt_t *ckp)
{
	ckp->ckp_size = P2ROUNDUP(ckp->ckp_size, _MAX_ALIGNMENT) + bp->buf_size;
	ckp->ckp_strn += strlen(bp->buf_name) + 1;
	ckp->ckp_secs++;
}

int dtrace_getstackdepth(dtrace_mstate_t *mstate, int aframes)
{
	uintptr_t		old = mstate->dtms_scratch_ptr;
	size_t			size;
	struct stacktrace_state	st = {
					NULL,
					NULL,
					0,
					aframes,
					STACKTRACE_KERNEL
				     };

	st.pcs = (uint64_t *)P2ROUNDUP(mstate->dtms_scratch_ptr, 8);
	size = (uintptr_t)st.pcs - mstate->dtms_scratch_ptr +
			  aframes * sizeof(uint64_t);
	if (mstate->dtms_scratch_ptr + size >
	    mstate->dtms_scratch_base + mstate->dtms_scratch_size) {
		DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
		return 0;
	}

	dtrace_stacktrace(&st);

	mstate->dtms_scratch_ptr = old;

	return st.depth;
}

/*ARGSUSED*/
static int
smb_open(dev_t *dp, int flag, int otyp, cred_t *cred)
{
	minor_t c;

	if (ksmbios == NULL)
		return (ENXIO);

	/*
	 * Locate and reserve a clone structure.  We skip clone 0 as that is
	 * the real minor number, and we assign a new minor to each clone.
	 */
	for (c = 1; c < smb_nclones; c++) {
		if (casptr(&smb_clones[c].c_hdl, NULL, ksmbios) == NULL)
			break;
	}

	if (c >= smb_nclones)
		return (EAGAIN);

	smb_clones[c].c_eplen = P2ROUNDUP(sizeof (smbios_entry_t), 16);
	smb_clones[c].c_stlen = smbios_buflen(smb_clones[c].c_hdl);

	*dp = makedevice(getemajor(*dp), c);

	(void) ddi_prop_update_int(*dp, smb_devi, "size",
	    smb_clones[c].c_eplen + smb_clones[c].c_stlen);

	return (0);
}

static fcf_secidx_t
fmd_ckpt_section(fmd_ckpt_t *ckp, const void *data, uint_t type, uint64_t size)
{
	const fmd_ckpt_desc_t *dp;

	ASSERT(type < sizeof (_fmd_ckpt_sections) / sizeof (fmd_ckpt_desc_t));
	dp = &_fmd_ckpt_sections[type];

	ckp->ckp_ptr = (uchar_t *)
	    P2ROUNDUP((uintptr_t)ckp->ckp_ptr, dp->secd_align);

	ckp->ckp_secp->fcfs_type = type;
	ckp->ckp_secp->fcfs_align = dp->secd_align;
	ckp->ckp_secp->fcfs_flags = 0;
	ckp->ckp_secp->fcfs_entsize = dp->secd_entsize;
	ckp->ckp_secp->fcfs_offset = (size_t)(ckp->ckp_ptr - ckp->ckp_buf);
	ckp->ckp_secp->fcfs_size = size;

	/*
	 * If the data pointer is non-NULL, copy the data to our buffer; else
	 * the caller is responsible for doing so and updating ckp->ckp_ptr.
	 */
	if (data != NULL) {
		bcopy(data, ckp->ckp_ptr, size);
		ckp->ckp_ptr += size;
	}

	ckp->ckp_secp++;
	return (ckp->ckp_secs++);
}

/*ARGSUSED*/
void
mach_cpucontext_free(struct cpu *cp, void *arg, int err)
{
	struct cpu_tables *ct = arg;

	ASSERT(&ct->ct_tss == cp->cpu_tss);

	switch (err) {
	case 0:
		break;
	case ETIMEDOUT:
		/*
		 * The processor was poked, but failed to start before
		 * we gave up waiting for it.  In case it starts later,
		 * don't free anything.
		 */
		break;
	default:
		/*
		 * Some other, passive, error occurred.
		 */
		kmem_free(ct, P2ROUNDUP(sizeof (*ct), PAGESIZE));
		cp->cpu_tss = NULL;
		break;
	}
}

void
flowadv_init(void)
{
	STAILQ_INIT(&fadv_list);

	/* Setup lock group and attribute for fadv_lock */
	fadv_lock_grp_attr = lck_grp_attr_alloc_init();
	fadv_lock_grp = lck_grp_alloc_init("fadv_lock", fadv_lock_grp_attr);
	lck_mtx_init(&fadv_lock, fadv_lock_grp, NULL);

	fadv_zone_size = P2ROUNDUP(sizeof (struct flowadv_fcentry),
	    sizeof (u_int64_t));
	fadv_zone = zinit(fadv_zone_size,
	    FADV_ZONE_MAX * fadv_zone_size, 0, FADV_ZONE_NAME);
	if (fadv_zone == NULL) {
		panic("%s: failed allocating %s", __func__, FADV_ZONE_NAME);
		/* NOTREACHED */
	}
	zone_change(fadv_zone, Z_EXPAND, TRUE);
	zone_change(fadv_zone, Z_CALLERACCT, FALSE);

	if (kernel_thread_start(flowadv_thread_func, NULL, &fadv_thread) !=
	    KERN_SUCCESS) {
		panic("%s: couldn't create flow event advisory thread",
		    __func__);
		/* NOTREACHED */
	}
	thread_deallocate(fadv_thread);
}

static void
fmd_ckpt_resv(fmd_ckpt_t *ckp, size_t size, size_t align)
{
	if (size != 0) {
		ckp->ckp_size = P2ROUNDUP(ckp->ckp_size, align) + size;
		ckp->ckp_secs++;
	}
}

static void
trim_map_vdev_commit(spa_t *spa, zio_t *zio, vdev_t *vd)
{
	trim_map_t *tm = vd->vdev_trimmap;
	trim_seg_t *ts;
	uint64_t size, offset, txgtarget, txgsafe;
	int64_t hard, soft;
	hrtime_t timelimit;

	ASSERT(vd->vdev_ops->vdev_op_leaf);

	if (tm == NULL)
		return;

	timelimit = gethrtime() - (hrtime_t)trim_timeout * NANOSEC;
	if (vd->vdev_isl2cache) {
		txgsafe = UINT64_MAX;
		txgtarget = UINT64_MAX;
	} else {
		txgsafe = MIN(spa_last_synced_txg(spa), spa_freeze_txg(spa));
		if (txgsafe > trim_txg_delay)
			txgtarget = txgsafe - trim_txg_delay;
		else
			txgtarget = 0;
	}

	mutex_enter(&tm->tm_lock);
	hard = 0;
	if (tm->tm_pending > trim_vdev_max_pending)
		hard = (tm->tm_pending - trim_vdev_max_pending) / 4;
	soft = P2ROUNDUP(hard + tm->tm_pending / trim_timeout + 1, 64);
	/* Loop until we have sent all outstanding free's */
	while (soft > 0 &&
	    (ts = trim_map_first(tm, txgtarget, txgsafe, timelimit, hard > 0))
	    != NULL) {
		TRIM_MAP_REM(tm, ts);
		avl_remove(&tm->tm_queued_frees, ts);
		avl_add(&tm->tm_inflight_frees, ts);
		size = ts->ts_end - ts->ts_start;
		offset = ts->ts_start;
		/*
		 * We drop the lock while we call zio_nowait as the IO
		 * scheduler can result in a different IO being run e.g.
		 * a write which would result in a recursive lock.
		 */
		mutex_exit(&tm->tm_lock);

		zio_nowait(zio_trim(zio, spa, vd, offset, size));

		soft -= TRIM_MAP_SEGS(size);
		hard -= TRIM_MAP_SEGS(size);
		mutex_enter(&tm->tm_lock);
	}
	mutex_exit(&tm->tm_lock);
}

/*ARGSUSED*/
static int
smb_segmap(dev_t dev, off_t off, struct as *as, caddr_t *addrp, off_t len,
    uint_t prot, uint_t maxprot, uint_t flags, cred_t *cred)
{
	smb_clone_t *cp = &smb_clones[getminor(dev)];

	size_t alen = P2ROUNDUP(len, PAGESIZE);
	caddr_t addr;

	iovec_t iov;
	uio_t uio;
	int err;

	if (len <= 0 || (flags & MAP_FIXED))
		return (EINVAL);

	if ((prot & PROT_WRITE) && (flags & MAP_SHARED))
		return (EACCES);

	if (off < 0 || off + len < off || off + len > cp->c_eplen + cp->c_stlen)
		return (ENXIO);

	as_rangelock(as);
	map_addr(&addr, alen, 0, 1, 0);

	if (addr != NULL)
		err = as_map(as, addr, alen, segvn_create, zfod_argsp);
	else
		err = ENOMEM;

	as_rangeunlock(as);
	*addrp = addr;

	if (err != 0)
		return (err);

	iov.iov_base = addr;
	iov.iov_len = len;

	bzero(&uio, sizeof (uio_t));
	uio.uio_iov = &iov;
	uio.uio_iovcnt = 1;
	uio.uio_offset = off;
	uio.uio_segflg = UIO_USERSPACE;
	uio.uio_extflg = UIO_COPY_DEFAULT;
	uio.uio_resid = len;

	if ((err = smb_uiomove(cp, &uio)) != 0)
		(void) as_unmap(as, addr, alen);

	return (err);
}

static int
zvol_discard(struct bio *bio)
{
	zvol_state_t *zv = bio->bi_bdev->bd_disk->private_data;
	uint64_t start = BIO_BI_SECTOR(bio) << 9;
	uint64_t size = BIO_BI_SIZE(bio);
	uint64_t end = start + size;
	int error;
	rl_t *rl;
	dmu_tx_t *tx;

	ASSERT(zv && zv->zv_open_count > 0);

	if (end > zv->zv_volsize)
		return (SET_ERROR(EIO));

	/*
	 * Align the request to volume block boundaries when REQ_SECURE is
	 * available, but not requested. If we don't, then this will force
	 * dnode_free_range() to zero out the unaligned parts, which is slow
	 * (read-modify-write) and useless since we are not freeing any space
	 * by doing so. Kernels that do not support REQ_SECURE (2.6.32 through
	 * 2.6.35) will not receive this optimization.
	 */
#ifdef REQ_SECURE
	if (!(bio->bi_rw & REQ_SECURE)) {
		start = P2ROUNDUP(start, zv->zv_volblocksize);
		end = P2ALIGN(end, zv->zv_volblocksize);
		size = end - start;
	}
#endif

	if (start >= end)
		return (0);

	rl = zfs_range_lock(&zv->zv_znode, start, size, RL_WRITER);
	tx = dmu_tx_create(zv->zv_objset);
	dmu_tx_mark_netfree(tx);
	error = dmu_tx_assign(tx, TXG_WAIT);
	if (error != 0) {
		dmu_tx_abort(tx);
	} else {
		zvol_log_truncate(zv, tx, start, size, B_TRUE);
		dmu_tx_commit(tx);
		error = dmu_free_long_range(zv->zv_objset,
		    ZVOL_OBJ, start, size);
	}

	zfs_range_unlock(rl);

	return (error);
}

kthread_t *
zk_thread_create(caddr_t stk, size_t stksize, thread_func_t func, void *arg,
    uint64_t len, proc_t *pp, int state, pri_t pri, int detachstate)
{
	kthread_t *kt;
	pthread_attr_t attr;
	char *stkstr;

	ASSERT0(state & ~TS_RUN);
	ASSERT0(len);

	kt = umem_zalloc(sizeof (kthread_t), UMEM_NOFAIL);
	kt->t_func = func;
	kt->t_arg = arg;
	kt->t_pri = pri;

	VERIFY0(pthread_attr_init(&attr));
	VERIFY0(pthread_attr_setdetachstate(&attr, detachstate));

	/*
	 * We allow the default stack size in user space to be specified by
	 * setting the ZFS_STACK_SIZE environment variable.  This allows us
	 * the convenience of observing and debugging stack overruns in
	 * user space.  Explicitly specified stack sizes will be honored.
	 * The usage of ZFS_STACK_SIZE is discussed further in the
	 * ENVIRONMENT VARIABLES sections of the ztest(1) man page.
	 */
	if (stksize == 0) {
		stkstr = getenv("ZFS_STACK_SIZE");

		if (stkstr == NULL)
			stksize = TS_STACK_MAX;
		else
			stksize = MAX(atoi(stkstr), TS_STACK_MIN);
	}

	VERIFY3S(stksize, >, 0);
	stksize = P2ROUNDUP(MAX(stksize, TS_STACK_MIN), PAGESIZE);
	/*
	 * If this ever fails, it may be because the stack size is not a
	 * multiple of system page size.
	 */
	VERIFY0(pthread_attr_setstacksize(&attr, stksize));
	VERIFY0(pthread_attr_setguardsize(&attr, PAGESIZE));

	VERIFY0(pthread_create(&kt->t_tid, &attr, &zk_thread_helper, kt));
	VERIFY0(pthread_attr_destroy(&attr));

	return (kt);
}