Re: [ckrm-tech] [RFC][PATCH 2/7] UBC: core (structures, API)

[Matt Helsley <matthltc@us.ibm.com>]

On Wed, 2006-08-16 at 19:37 +0400, Kirill Korotaev wrote:
> Core functionality and interfaces of UBC:
> find/create beancounter, initialization,
> charge/uncharge of resource, core objects' declarations.
> 
> Basic structures:
>   ubparm           - resource description
>   user_beancounter - set of resources, id, lock
> 
> Signed-Off-By: Pavel Emelianov <xemul@sw.ru>
> Signed-Off-By: Kirill Korotaev <dev@sw.ru>
> 
> ---
>  include/ub/beancounter.h |  157 ++++++++++++++++++
>  init/main.c              |    4
>  kernel/Makefile          |    1
>  kernel/ub/Makefile       |    7
>  kernel/ub/beancounter.c  |  398 +++++++++++++++++++++++++++++++++++++++++++++++
>  5 files changed, 567 insertions(+)
> 
> --- /dev/null	2006-07-18 14:52:43.075228448 +0400
> +++ ./include/ub/beancounter.h	2006-08-10 14:58:27.000000000 +0400
> @@ -0,0 +1,157 @@
> +/*
> + *  include/ub/beancounter.h
> + *
> + *  Copyright (C) 2006 OpenVZ. SWsoft Inc
> + *
> + */
> +
> +#ifndef _LINUX_BEANCOUNTER_H
> +#define _LINUX_BEANCOUNTER_H
> +
> +/*
> + *	Resource list.
> + */
> +
> +#define UB_RESOURCES	0
> +
> +struct ubparm {
> +	/*
> +	 * A barrier over which resource allocations are failed gracefully.
> +	 * e.g. if the amount of consumed memory is over the barrier further
> +	 * sbrk() or mmap() calls fail, the existing processes are not killed.
> +	 */
> +	unsigned long	barrier;
> +	/* hard resource limit */
> +	unsigned long	limit;
> +	/* consumed resources */
> +	unsigned long	held;
> +	/* maximum amount of consumed resources through the last period */
> +	unsigned long	maxheld;
> +	/* minimum amount of consumed resources through the last period */
> +	unsigned long	minheld;
> +	/* count of failed charges */
> +	unsigned long	failcnt;
> +};
> +
> +/*
> + * Kernel internal part.
> + */
> +
> +#ifdef __KERNEL__
> +
> +#include <linux/config.h>
> +#include <linux/spinlock.h>
> +#include <linux/list.h>
> +#include <asm/atomic.h>
> +
> +/*
> + * UB_MAXVALUE is essentially LONG_MAX declared in a cross-compiling safe form.
> + */
> +#define UB_MAXVALUE	( (1UL << (sizeof(unsigned long)*8-1)) - 1)
> +
> +
> +/*
> + *	Resource management structures
> + * Serialization issues:
> + *   beancounter list management is protected via ub_hash_lock
> + *   task pointers are set only for current task and only once
> + *   refcount is managed atomically
> + *   value and limit comparison and change are protected by per-ub spinlock
> + */
> +
> +struct user_beancounter
> +{
> +	atomic_t		ub_refcount;
> +	spinlock_t		ub_lock;
> +	uid_t			ub_uid;
> +	struct hlist_node	hash;
> +
> +	struct user_beancounter	*parent;
> +	void			*private_data;
> +
> +	/* resources statistics and settings */
> +	struct ubparm		ub_parms[UB_RESOURCES];
> +};
> +
> +enum severity { UB_BARRIER, UB_LIMIT, UB_FORCE };
> +
> +/* Flags passed to beancounter_findcreate() */
> +#define UB_LOOKUP_SUB		0x01 /* Lookup subbeancounter */
> +#define UB_ALLOC		0x02 /* May allocate new one */
> +#define UB_ALLOC_ATOMIC		0x04 /* Allocate with GFP_ATOMIC */
> +
> +#define UB_HASH_SIZE		256
> +
> +#ifdef CONFIG_USER_RESOURCE
> +extern struct hlist_head ub_hash[];
> +extern spinlock_t ub_hash_lock;
> +
> +static inline void ub_adjust_held_minmax(struct user_beancounter *ub,
> +		int resource)
> +{
> +	if (ub->ub_parms[resource].maxheld < ub->ub_parms[resource].held)
> +		ub->ub_parms[resource].maxheld = ub->ub_parms[resource].held;
> +	if (ub->ub_parms[resource].minheld > ub->ub_parms[resource].held)
> +		ub->ub_parms[resource].minheld = ub->ub_parms[resource].held;
> +}
> +
> +void ub_print_resource_warning(struct user_beancounter *ub, int res,
> +		char *str, unsigned long val, unsigned long held);
> +void ub_print_uid(struct user_beancounter *ub, char *str, int size);
> +
> +int  __charge_beancounter_locked(struct user_beancounter *ub,
> +		int resource, unsigned long val, enum severity strict);
> +void charge_beancounter_notop(struct user_beancounter *ub,
> +		int resource, unsigned long val);
> +int  charge_beancounter(struct user_beancounter *ub,
> +		int resource, unsigned long val, enum severity strict);
> +
> +void __uncharge_beancounter_locked(struct user_beancounter *ub,
> +		int resource, unsigned long val);
> +void uncharge_beancounter_notop(struct user_beancounter *ub,
> +		int resource, unsigned long val);
> +void uncharge_beancounter(struct user_beancounter *ub,
> +		int resource, unsigned long val);
> +
> +struct user_beancounter *beancounter_findcreate(uid_t uid,
> +		struct user_beancounter *parent, int flags);
> +
> +static inline struct user_beancounter *get_beancounter(
> +		struct user_beancounter *ub)
> +{
> +	atomic_inc(&ub->ub_refcount);
> +	return ub;
> +}
> +
> +void __put_beancounter(struct user_beancounter *ub);
> +static inline void put_beancounter(struct user_beancounter *ub)
> +{
> +	__put_beancounter(ub);
> +}
> +
> +void ub_init_early(void);
> +void ub_init_late(void);
> +void ub_init_proc(void);
> +
> +extern struct user_beancounter ub0;
> +extern const char *ub_rnames[];
> +
> +#else /* CONFIG_USER_RESOURCE */
> +
> +#define beancounter_findcreate(id, p, f)		(NULL)
> +#define get_beancounter(ub)				(NULL)
> +#define put_beancounter(ub)				do { } while (0)
> +#define __charge_beancounter_locked(ub, r, v, s)	(0)
> +#define charge_beancounter(ub, r, v, s)			(0)
> +#define charge_beancounter_notop(ub, r, v)		do { } while (0)
> +#define __uncharge_beancounter_locked(ub, r, v)		do { } while (0)
> +#define uncharge_beancounter(ub, r, v)			do { } while (0)
> +#define uncharge_beancounter_notop(ub, r, v)		do { } while (0)
> +#define ub_init_early()					do { } while (0)
> +#define ub_init_late()					do { } while (0)
> +#define ub_init_proc()					do { } while (0)
> +
> +#endif /* CONFIG_USER_RESOURCE */
> +#endif /* __KERNEL__ */
> +
> +#endif /* _LINUX_BEANCOUNTER_H */
> --- ./init/main.c.ubcore	2006-08-10 14:55:47.000000000 +0400
> +++ ./init/main.c	2006-08-10 14:57:01.000000000 +0400
> @@ -52,6 +52,8 @@
>  #include <linux/debug_locks.h>
>  #include <linux/lockdep.h>
>  
> +#include <ub/beancounter.h>
> +
>  #include <asm/io.h>
>  #include <asm/bugs.h>
>  #include <asm/setup.h>
> @@ -470,6 +472,7 @@ asmlinkage void __init start_kernel(void
>  	early_boot_irqs_off();
>  	early_init_irq_lock_class();
>  
> +	ub_init_early();
>  /*
>   * Interrupts are still disabled. Do necessary setups, then
>   * enable them
> @@ -563,6 +566,7 @@ asmlinkage void __init start_kernel(void
>  #endif
>  	fork_init(num_physpages);
>  	proc_caches_init();
> +	ub_init_late();
>  	buffer_init();
>  	unnamed_dev_init();
>  	key_init();
> --- ./kernel/Makefile.ubcore	2006-08-10 14:55:47.000000000 +0400
> +++ ./kernel/Makefile	2006-08-10 14:57:01.000000000 +0400
> @@ -12,6 +12,7 @@ obj-y     = sched.o fork.o exec_domain.o
>  
>  obj-$(CONFIG_STACKTRACE) += stacktrace.o
>  obj-y += time/
> +obj-y += ub/
>  obj-$(CONFIG_DEBUG_MUTEXES) += mutex-debug.o
>  obj-$(CONFIG_LOCKDEP) += lockdep.o
>  ifeq ($(CONFIG_PROC_FS),y)
> --- /dev/null	2006-07-18 14:52:43.075228448 +0400
> +++ ./kernel/ub/Makefile	2006-08-10 14:57:01.000000000 +0400
> @@ -0,0 +1,7 @@
> +#
> +# User resources part (UBC)
> +#
> +# Copyright (C) 2006 OpenVZ. SWsoft Inc
> +#
> +
> +obj-$(CONFIG_USER_RESOURCE) += beancounter.o
> --- /dev/null	2006-07-18 14:52:43.075228448 +0400
> +++ ./kernel/ub/beancounter.c	2006-08-10 15:09:34.000000000 +0400
> @@ -0,0 +1,398 @@
> +/*
> + *  kernel/ub/beancounter.c
> + *
> + *  Copyright (C) 2006 OpenVZ. SWsoft Inc
> + *  Original code by (C) 1998      Alan Cox
> + *                       1998-2000 Andrey Savochkin <saw@saw.sw.com.sg>
> + */
> +
> +#include <linux/slab.h>
> +#include <linux/module.h>
> +
> +#include <ub/beancounter.h>
> +
> +static kmem_cache_t *ub_cachep;
> +static struct user_beancounter default_beancounter;
> +static struct user_beancounter default_subbeancounter;
> +
> +static void init_beancounter_struct(struct user_beancounter *ub, uid_t id);
> +
> +struct user_beancounter ub0;
> +
> +const char *ub_rnames[] = {
> +};
> +
> +#define ub_hash_fun(x) ((((x) >> 8) ^ (x)) & (UB_HASH_SIZE - 1))
> +#define ub_subhash_fun(p, id) ub_hash_fun((p)->ub_uid + (id) * 17)
> +
> +struct hlist_head ub_hash[UB_HASH_SIZE];
> +spinlock_t ub_hash_lock;
> +
> +EXPORT_SYMBOL(ub_hash);
> +EXPORT_SYMBOL(ub_hash_lock);
> +
> +/*
> + *	Per user resource beancounting. Resources are tied to their luid.

You haven't explained what an luid is at this point in the patch series.
Patch 0 says:

diff-ubc-syscalls.patch:
    Patch adds system calls for UB management:
    1. sys_getluid    - get current UB id

But I have no idea what that l is there for. Why not sys_get_ubid() for
instance?

> + *	The resource structure itself is tagged both to the process and
> + *	the charging resources (a socket doesn't want to have to search for
> + *	things at irq time for example). Reference counters keep things in
> + *	hand.
> + *
> + *	The case where a user creates resource, kills all his processes and
> + *	then starts new ones is correctly handled this way. The refcounters
> + *	will mean the old entry is still around with resource tied to it.
> + */
> +

So we create one beancounter object for every resource the user's tasks
allocate? For instance, one per socket? Or does "resource structure"
refer to something else?

> +struct user_beancounter *beancounter_findcreate(uid_t uid,
> +		struct user_beancounter *p, int mask)
> +{
> +	struct user_beancounter *new_ub, *ub, *tmpl_ub;
> +	unsigned long flags;
> +	struct hlist_head *slot;
> +	struct hlist_node *pos;
> +
> +	if (mask & UB_LOOKUP_SUB) {
> +		WARN_ON(p == NULL);
> +		tmpl_ub = &default_subbeancounter;
> +		slot = &ub_hash[ub_subhash_fun(p, uid)];
> +	} else {
> +		WARN_ON(p != NULL);
> +		tmpl_ub = &default_beancounter;
> +		slot = &ub_hash[ub_hash_fun(uid)];
> +	}
> +	new_ub = NULL;
> +
> +retry:
> +	spin_lock_irqsave(&ub_hash_lock, flags);
> +	hlist_for_each_entry (ub, pos, slot, hash)
> +		if (ub->ub_uid == uid && ub->parent == p)
> +			break;
> +
> +	if (pos != NULL) {
> +		get_beancounter(ub);
> +		spin_unlock_irqrestore(&ub_hash_lock, flags);
> +
> +		if (new_ub != NULL) {
> +			put_beancounter(new_ub->parent);
> +			kmem_cache_free(ub_cachep, new_ub);
> +		}
> +		return ub;
> +	}
> +
> +	if (!(mask & UB_ALLOC))
> +		goto out_unlock;
> +
> +	if (new_ub != NULL)
> +		goto out_install;
> +
> +	if (mask & UB_ALLOC_ATOMIC) {

This block..

> +		new_ub = kmem_cache_alloc(ub_cachep, GFP_ATOMIC);
> +		if (new_ub == NULL)
> +			goto out_unlock;
> +
> +		memcpy(new_ub, tmpl_ub, sizeof(*new_ub));
> +		init_beancounter_struct(new_ub, uid);
> +		if (p)
> +			new_ub->parent = get_beancounter(p);

ending here is almost exactly the same as the block ..

> +		goto out_install;
> +	}
> +
> +	spin_unlock_irqrestore(&ub_hash_lock, flags);
> +

>From here..

> +	new_ub = kmem_cache_alloc(ub_cachep, GFP_KERNEL);
> +	if (new_ub == NULL)
> +		goto out;
> +
> +	memcpy(new_ub, tmpl_ub, sizeof(*new_ub));
> +	init_beancounter_struct(new_ub, uid);
> +	if (p)
> +		new_ub->parent = get_beancounter(p);

to here. You could make a flag variable that holds GFP_ATOMIC or
GFP_KERNEL based on mask & UB_ALLOC_ATOMIC and perhaps turn this block
into a small helper.

> +	goto retry;
> +
> +out_install:
> +	hlist_add_head(&new_ub->hash, slot);
> +out_unlock:
> +	spin_unlock_irqrestore(&ub_hash_lock, flags);
> +out:
> +	return new_ub;
> +}
> +
> +EXPORT_SYMBOL(beancounter_findcreate);
> +
> +void ub_print_uid(struct user_beancounter *ub, char *str, int size)
> +{
> +	if (ub->parent != NULL)
> +		snprintf(str, size, "%u.%u", ub->parent->ub_uid, ub->ub_uid);
> +	else
> +		snprintf(str, size, "%u", ub->ub_uid);
> +}
> +
> +EXPORT_SYMBOL(ub_print_uid);

>From what I can see this patch doesn't really justify the need for the
EXPORT_SYMBOL. Shouldn't that be done in the patch where it's needed
outside of the kernel/ub code itself?

> +void ub_print_resource_warning(struct user_beancounter *ub, int res,
> +		char *str, unsigned long val, unsigned long held)
> +{
> +	char uid[64];
> +
> +	ub_print_uid(ub, uid, sizeof(uid));
> +	printk(KERN_WARNING "UB %s %s warning: %s "
> +			"(held %lu, fails %lu, val %lu)\n",
> +			uid, ub_rnames[res], str,
> +			(res < UB_RESOURCES ? ub->ub_parms[res].held : held),
> +			(res < UB_RESOURCES ? ub->ub_parms[res].failcnt : 0),
> +			val);
> +}
> +
> +EXPORT_SYMBOL(ub_print_resource_warning);
> +
> +static inline void verify_held(struct user_beancounter *ub)
> +{
> +	int i;
> +
> +	for (i = 0; i < UB_RESOURCES; i++)
> +		if (ub->ub_parms[i].held != 0)
> +			ub_print_resource_warning(ub, i,
> +					"resource is held on put", 0, 0);
> +}
> +
> +void __put_beancounter(struct user_beancounter *ub)
> +{
> +	unsigned long flags;
> +	struct user_beancounter *parent;
> +
> +again:
> +	parent = ub->parent;
> +	/* equevalent to atomic_dec_and_lock_irqsave() */

nit: s/que/qui/

> +	local_irq_save(flags);
> +	if (likely(!atomic_dec_and_lock(&ub->ub_refcount, &ub_hash_lock))) {
> +		if (unlikely(atomic_read(&ub->ub_refcount) < 0))
> +			printk(KERN_ERR "UB: Bad ub refcount: ub=%p, "
> +					"luid=%d, ref=%d\n",
> +					ub, ub->ub_uid,
> +					atomic_read(&ub->ub_refcount));

This seems to be for debugging purposes only. If not, perhaps this
printk ought to be rate limited?

> +		local_irq_restore(flags);
> +		return;
> +	}
> +
> +	if (unlikely(ub == &ub0)) {
> +		printk(KERN_ERR "Trying to put ub0\n");

Same thing for this printk.

> +		spin_unlock_irqrestore(&ub_hash_lock, flags);
> +		return;
> +	}
> +
> +	verify_held(ub);
> +	hlist_del(&ub->hash);
> +	spin_unlock_irqrestore(&ub_hash_lock, flags);
> +
> +	kmem_cache_free(ub_cachep, ub);
> +
> +	ub = parent;
> +	if (ub != NULL)
> +		goto again;

Couldn't this be replaced by a do { } while (ub != NULL); loop?

> +}
> +
> +EXPORT_SYMBOL(__put_beancounter);
> +
> +/*
> + *	Generic resource charging stuff
> + */
> +
> +int __charge_beancounter_locked(struct user_beancounter *ub,
> +		int resource, unsigned long val, enum severity strict)
> +{
> +	/*
> +	 * ub_value <= UB_MAXVALUE, value <= UB_MAXVALUE, and only one addition
> +	 * at the moment is possible so an overflow is impossible.  
> +	 */
> +	ub->ub_parms[resource].held += val;
> +
> +	switch (strict) {
> +		case UB_BARRIER:
> +			if (ub->ub_parms[resource].held >
> +					ub->ub_parms[resource].barrier)
> +				break;
> +			/* fallthrough */
> +		case UB_LIMIT:
> +			if (ub->ub_parms[resource].held >
> +					ub->ub_parms[resource].limit)
> +				break;
> +			/* fallthrough */
> +		case UB_FORCE:
> +			ub_adjust_held_minmax(ub, resource);
> +			return 0;
> +		default:
> +			BUG();
> +	}
> +
> +	ub->ub_parms[resource].failcnt++;
> +	ub->ub_parms[resource].held -= val;
> +	return -ENOMEM;
> +}
> +
> +int charge_beancounter(struct user_beancounter *ub,
> +		int resource, unsigned long val, enum severity strict)
> +{
> +	int retval;
> +	struct user_beancounter *p, *q;
> +	unsigned long flags;
> +
> +	retval = -EINVAL;
> +	BUG_ON(val > UB_MAXVALUE);
> +
> +	local_irq_save(flags);

<factor>

> +	for (p = ub; p != NULL; p = p->parent) {

Seems rather expensive to walk up the tree for every charge. Especially
if the administrator wants a fine degree of resource control and makes a
tall tree. This would be a problem especially when it comes to resources
that require frequent and fast allocation.

> +		spin_lock(&p->ub_lock);
> +		retval = __charge_beancounter_locked(p, resource, val, strict);
> +		spin_unlock(&p->ub_lock);
> +		if (retval)
> +			goto unroll;

This can be factored by passing a flag that breaks the loop on an error:

		if (retval && do_break_err)
			return retval;

> +	}

</factor>

> +out_restore:
> +	local_irq_restore(flags);
> +	return retval;
> +

<factor>

> +unroll:
> +	for (q = ub; q != p; q = q->parent) {
> +		spin_lock(&q->ub_lock);
> +		__uncharge_beancounter_locked(q, resource, val);
> +		spin_unlock(&q->ub_lock);
> +	}

</factor>

> +	goto out_restore;
> +}
> +
> +EXPORT_SYMBOL(charge_beancounter);
> +
> +void charge_beancounter_notop(struct user_beancounter *ub,
> +		int resource, unsigned long val)
> +{
> +	struct user_beancounter *p;
> +	unsigned long flags;
> +
> +	local_irq_save(flags);

<factor>

> +	for (p = ub; p->parent != NULL; p = p->parent) {
> +		spin_lock(&p->ub_lock);
> +		__charge_beancounter_locked(p, resource, val, UB_FORCE);
> +		spin_unlock(&p->ub_lock);
> +	}

<factor>

> +	local_irq_restore(flags);

Again, this could be factored with charge_beancounter using a helper
function.

> +}
> +
> +EXPORT_SYMBOL(charge_beancounter_notop);
> +
> +void __uncharge_beancounter_locked(struct user_beancounter *ub,
> +		int resource, unsigned long val)
> +{
> +	if (unlikely(ub->ub_parms[resource].held < val)) {
> +		ub_print_resource_warning(ub, resource,
> +				"uncharging too much", val, 0);
> +		val = ub->ub_parms[resource].held;
> +	}
> +	ub->ub_parms[resource].held -= val;
> +	ub_adjust_held_minmax(ub, resource);
> +}
> +
> +void uncharge_beancounter(struct user_beancounter *ub,
> +		int resource, unsigned long val)
> +{
> +	unsigned long flags;
> +	struct user_beancounter *p;
> +
> +	for (p = ub; p != NULL; p = p->parent) {
> +		spin_lock_irqsave(&p->ub_lock, flags);
> +		__uncharge_beancounter_locked(p, resource, val);
> +		spin_unlock_irqrestore(&p->ub_lock, flags);
> +	}
> +}

Looks like your unroll: label in charge_beancounter above.

> +
> +EXPORT_SYMBOL(uncharge_beancounter);
> +
> +void uncharge_beancounter_notop(struct user_beancounter *ub,
> +		int resource, unsigned long val)
> +{
> +	struct user_beancounter *p;
> +	unsigned long flags;
> +
> +	local_irq_save(flags);

<factor>

> +	for (p = ub; p->parent != NULL; p = p->parent) {
> +		spin_lock(&p->ub_lock);
> +		__uncharge_beancounter_locked(p, resource, val);
> +		spin_unlock(&p->ub_lock);
> +	}

</factor>

> +	local_irq_restore(flags);
> +}
> +
> +EXPORT_SYMBOL(uncharge_beancounter_notop);
> +
> +/*
> + *	Initialization
> + *
> + *	struct user_beancounter contains
> + *	 - limits and other configuration settings
> + *	 - structural fields: lists, spinlocks and so on.
> + *
> + *	Before these parts are initialized, the structure should be memset
> + *	to 0 or copied from a known clean structure.  That takes care of a lot
> + *	of fields not initialized explicitly.
> + */
> +
> +static void init_beancounter_struct(struct user_beancounter *ub, uid_t id)
> +{
> +	atomic_set(&ub->ub_refcount, 1);
> +	spin_lock_init(&ub->ub_lock);
> +	ub->ub_uid = id;
> +}
> +
> +static void init_beancounter_nolimits(struct user_beancounter *ub)
> +{
> +	int k;
> +
> +	for (k = 0; k < UB_RESOURCES; k++) {
> +		ub->ub_parms[k].limit = UB_MAXVALUE;
> +		ub->ub_parms[k].barrier = UB_MAXVALUE;
> +	}
> +}
> +
> +static void init_beancounter_syslimits(struct user_beancounter *ub)
> +{
> +	int k;
> +
> +	for (k = 0; k < UB_RESOURCES; k++)
> +		ub->ub_parms[k].barrier = ub->ub_parms[k].limit;
> +}
> +
> +void __init ub_init_early(void)
> +{
> +	struct user_beancounter *ub;
> +	struct hlist_head *slot;
> +
> +	ub = &ub0;
> +

<factor>

> +	memset(ub, 0, sizeof(*ub));
> +	init_beancounter_nolimits(ub);
> +	init_beancounter_struct(ub, 0);
> +

</factor>

> +	spin_lock_init(&ub_hash_lock);
> +	slot = &ub_hash[ub_hash_fun(ub->ub_uid)];
> +	hlist_add_head(&ub->hash, slot);
> +}
> +
> +void __init ub_init_late(void)
> +{
> +	struct user_beancounter *ub;
> +
> +	ub_cachep = kmem_cache_create("user_beancounters",
> +			sizeof(struct user_beancounter),
> +			0, SLAB_HWCACHE_ALIGN, NULL, NULL);
> +	if (ub_cachep == NULL)
> +		panic("Can't create ubc caches\n");
> +
> +	ub = &default_beancounter;

<factor>

> +	memset(ub, 0, sizeof(default_beancounter));
> +	init_beancounter_syslimits(ub);
> +	init_beancounter_struct(ub, 0);
> +

</factor>

> +	ub = &default_subbeancounter;

<factor>

> +	memset(ub, 0, sizeof(default_subbeancounter));
> +	init_beancounter_nolimits(ub);
> +	init_beancounter_struct(ub, 0);

</factor>

> +}

Cheers,
	-Matt Helsley