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freebsd-dev/sys/vm/uma.h
Lawrence Stewart 1c6cae9711 Change uma_zone_set_max to return the effective value of "nitems" after 
rounding. The same value can also be obtained with uma_zone_get_max, but this
change avoids a caller having to make two back-to-back calls.

Sponsored by:	FreeBSD Foundation
Reviewed by:	gnn, jhb
2010-10-16 04:41:45 +00:00

639 lines
19 KiB
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/*-
* Copyright (c) 2002, 2003, 2004, 2005 Jeffrey Roberson <jeff@FreeBSD.org>
* Copyright (c) 2004, 2005 Bosko Milekic <bmilekic@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice unmodified, this list of conditions, and the following
* disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $FreeBSD$
*
*/
/*
* uma.h - External definitions for the Universal Memory Allocator
*
*/
#ifndef VM_UMA_H
#define VM_UMA_H
#include <sys/param.h> /* For NULL */
#include <sys/malloc.h> /* For M_* */
/* User visible parameters */
#define UMA_SMALLEST_UNIT (PAGE_SIZE / 256) /* Smallest item allocated */
/* Types and type defs */
struct uma_zone;
/* Opaque type used as a handle to the zone */
typedef struct uma_zone * uma_zone_t;
void zone_drain(uma_zone_t);
/*
* Item constructor
*
* Arguments:
* item A pointer to the memory which has been allocated.
* arg The arg field passed to uma_zalloc_arg
* size The size of the allocated item
* flags See zalloc flags
*
* Returns:
* 0 on success
* errno on failure
*
* Discussion:
* The constructor is called just before the memory is returned
* to the user. It may block if necessary.
*/
typedef int (*uma_ctor)(void *mem, int size, void *arg, int flags);
/*
* Item destructor
*
* Arguments:
* item A pointer to the memory which has been allocated.
* size The size of the item being destructed.
* arg Argument passed through uma_zfree_arg
*
* Returns:
* Nothing
*
* Discussion:
* The destructor may perform operations that differ from those performed
* by the initializer, but it must leave the object in the same state.
* This IS type stable storage. This is called after EVERY zfree call.
*/
typedef void (*uma_dtor)(void *mem, int size, void *arg);
/*
* Item initializer
*
* Arguments:
* item A pointer to the memory which has been allocated.
* size The size of the item being initialized.
* flags See zalloc flags
*
* Returns:
* 0 on success
* errno on failure
*
* Discussion:
* The initializer is called when the memory is cached in the uma zone.
* The initializer and the destructor should leave the object in the same
* state.
*/
typedef int (*uma_init)(void *mem, int size, int flags);
/*
* Item discard function
*
* Arguments:
* item A pointer to memory which has been 'freed' but has not left the
* zone's cache.
* size The size of the item being discarded.
*
* Returns:
* Nothing
*
* Discussion:
* This routine is called when memory leaves a zone and is returned to the
* system for other uses. It is the counter-part to the init function.
*/
typedef void (*uma_fini)(void *mem, int size);
/*
* What's the difference between initializing and constructing?
*
* The item is initialized when it is cached, and this is the state that the
* object should be in when returned to the allocator. The purpose of this is
* to remove some code which would otherwise be called on each allocation by
* utilizing a known, stable state. This differs from the constructor which
* will be called on EVERY allocation.
*
* For example, in the initializer you may want to initialize embedded locks,
* NULL list pointers, set up initial states, magic numbers, etc. This way if
* the object is held in the allocator and re-used it won't be necessary to
* re-initialize it.
*
* The constructor may be used to lock a data structure, link it on to lists,
* bump reference counts or total counts of outstanding structures, etc.
*
*/
/* Function proto types */
/*
* Create a new uma zone
*
* Arguments:
* name The text name of the zone for debugging and stats. This memory
* should not be freed until the zone has been deallocated.
* size The size of the object that is being created.
* ctor The constructor that is called when the object is allocated.
* dtor The destructor that is called when the object is freed.
* init An initializer that sets up the initial state of the memory.
* fini A discard function that undoes initialization done by init.
* ctor/dtor/init/fini may all be null, see notes above.
* align A bitmask that corresponds to the requested alignment
* eg 4 would be 0x3
* flags A set of parameters that control the behavior of the zone.
*
* Returns:
* A pointer to a structure which is intended to be opaque to users of
* the interface. The value may be null if the wait flag is not set.
*/
uma_zone_t uma_zcreate(char *name, size_t size, uma_ctor ctor, uma_dtor dtor,
uma_init uminit, uma_fini fini, int align,
u_int32_t flags);
/*
* Create a secondary uma zone
*
* Arguments:
* name The text name of the zone for debugging and stats. This memory
* should not be freed until the zone has been deallocated.
* ctor The constructor that is called when the object is allocated.
* dtor The destructor that is called when the object is freed.
* zinit An initializer that sets up the initial state of the memory
* as the object passes from the Keg's slab to the Zone's cache.
* zfini A discard function that undoes initialization done by init
* as the object passes from the Zone's cache to the Keg's slab.
*
* ctor/dtor/zinit/zfini may all be null, see notes above.
* Note that the zinit and zfini specified here are NOT
* exactly the same as the init/fini specified to uma_zcreate()
* when creating a master zone. These zinit/zfini are called
* on the TRANSITION from keg to zone (and vice-versa). Once
* these are set, the primary zone may alter its init/fini
* (which are called when the object passes from VM to keg)
* using uma_zone_set_init/fini()) as well as its own
* zinit/zfini (unset by default for master zone) with
* uma_zone_set_zinit/zfini() (note subtle 'z' prefix).
*
* master A reference to this zone's Master Zone (Primary Zone),
* which contains the backing Keg for the Secondary Zone
* being added.
*
* Returns:
* A pointer to a structure which is intended to be opaque to users of
* the interface. The value may be null if the wait flag is not set.
*/
uma_zone_t uma_zsecond_create(char *name, uma_ctor ctor, uma_dtor dtor,
uma_init zinit, uma_fini zfini, uma_zone_t master);
/*
* Add a second master to a secondary zone. This provides multiple data
* backends for objects with the same size. Both masters must have
* compatible allocation flags. Presently, UMA_ZONE_MALLOC type zones are
* the only supported.
*
* Returns:
* Error on failure, 0 on success.
*/
int uma_zsecond_add(uma_zone_t zone, uma_zone_t master);
/*
* Definitions for uma_zcreate flags
*
* These flags share space with UMA_ZFLAGs in uma_int.h. Be careful not to
* overlap when adding new features. 0xf0000000 is in use by uma_int.h.
*/
#define UMA_ZONE_PAGEABLE 0x0001 /* Return items not fully backed by
physical memory XXX Not yet */
#define UMA_ZONE_ZINIT 0x0002 /* Initialize with zeros */
#define UMA_ZONE_STATIC 0x0004 /* Statically sized zone */
#define UMA_ZONE_OFFPAGE 0x0008 /* Force the slab structure allocation
off of the real memory */
#define UMA_ZONE_MALLOC 0x0010 /* For use by malloc(9) only! */
#define UMA_ZONE_NOFREE 0x0020 /* Do not free slabs of this type! */
#define UMA_ZONE_MTXCLASS 0x0040 /* Create a new lock class */
#define UMA_ZONE_VM 0x0080 /*
* Used for internal vm datastructures
* only.
*/
#define UMA_ZONE_HASH 0x0100 /*
* Use a hash table instead of caching
* information in the vm_page.
*/
#define UMA_ZONE_SECONDARY 0x0200 /* Zone is a Secondary Zone */
#define UMA_ZONE_REFCNT 0x0400 /* Allocate refcnts in slabs */
#define UMA_ZONE_MAXBUCKET 0x0800 /* Use largest buckets */
#define UMA_ZONE_CACHESPREAD 0x1000 /*
* Spread memory start locations across
* all possible cache lines. May
* require many virtually contiguous
* backend pages and can fail early.
*/
#define UMA_ZONE_VTOSLAB 0x2000 /* Zone uses vtoslab for lookup. */
/*
* These flags are shared between the keg and zone. In zones wishing to add
* new kegs these flags must be compatible. Some are determined based on
* physical parameters of the request and may not be provided by the consumer.
*/
#define UMA_ZONE_INHERIT \
(UMA_ZONE_OFFPAGE | UMA_ZONE_MALLOC | UMA_ZONE_HASH | \
UMA_ZONE_REFCNT | UMA_ZONE_VTOSLAB)
/* Definitions for align */
#define UMA_ALIGN_PTR (sizeof(void *) - 1) /* Alignment fit for ptr */
#define UMA_ALIGN_LONG (sizeof(long) - 1) /* "" long */
#define UMA_ALIGN_INT (sizeof(int) - 1) /* "" int */
#define UMA_ALIGN_SHORT (sizeof(short) - 1) /* "" short */
#define UMA_ALIGN_CHAR (sizeof(char) - 1) /* "" char */
#define UMA_ALIGN_CACHE (0 - 1) /* Cache line size align */
/*
* Destroys an empty uma zone. If the zone is not empty uma complains loudly.
*
* Arguments:
* zone The zone we want to destroy.
*
*/
void uma_zdestroy(uma_zone_t zone);
/*
* Allocates an item out of a zone
*
* Arguments:
* zone The zone we are allocating from
* arg This data is passed to the ctor function
* flags See sys/malloc.h for available flags.
*
* Returns:
* A non-null pointer to an initialized element from the zone is
* guaranteed if the wait flag is M_WAITOK. Otherwise a null pointer
* may be returned if the zone is empty or the ctor failed.
*/
void *uma_zalloc_arg(uma_zone_t zone, void *arg, int flags);
/*
* Allocates an item out of a zone without supplying an argument
*
* This is just a wrapper for uma_zalloc_arg for convenience.
*
*/
static __inline void *uma_zalloc(uma_zone_t zone, int flags);
static __inline void *
uma_zalloc(uma_zone_t zone, int flags)
{
return uma_zalloc_arg(zone, NULL, flags);
}
/*
* Frees an item back into the specified zone.
*
* Arguments:
* zone The zone the item was originally allocated out of.
* item The memory to be freed.
* arg Argument passed to the destructor
*
* Returns:
* Nothing.
*/
void uma_zfree_arg(uma_zone_t zone, void *item, void *arg);
/*
* Frees an item back to a zone without supplying an argument
*
* This is just a wrapper for uma_zfree_arg for convenience.
*
*/
static __inline void uma_zfree(uma_zone_t zone, void *item);
static __inline void
uma_zfree(uma_zone_t zone, void *item)
{
uma_zfree_arg(zone, item, NULL);
}
/*
* XXX The rest of the prototypes in this header are h0h0 magic for the VM.
* If you think you need to use it for a normal zone you're probably incorrect.
*/
/*
* Backend page supplier routines
*
* Arguments:
* zone The zone that is requesting pages.
* size The number of bytes being requested.
* pflag Flags for these memory pages, see below.
* wait Indicates our willingness to block.
*
* Returns:
* A pointer to the allocated memory or NULL on failure.
*/
typedef void *(*uma_alloc)(uma_zone_t zone, int size, u_int8_t *pflag, int wait);
/*
* Backend page free routines
*
* Arguments:
* item A pointer to the previously allocated pages.
* size The original size of the allocation.
* pflag The flags for the slab. See UMA_SLAB_* below.
*
* Returns:
* None
*/
typedef void (*uma_free)(void *item, int size, u_int8_t pflag);
/*
* Sets up the uma allocator. (Called by vm_mem_init)
*
* Arguments:
* bootmem A pointer to memory used to bootstrap the system.
*
* Returns:
* Nothing
*
* Discussion:
* This memory is used for zones which allocate things before the
* backend page supplier can give us pages. It should be
* UMA_SLAB_SIZE * boot_pages bytes. (see uma_int.h)
*
*/
void uma_startup(void *bootmem, int boot_pages);
/*
* Finishes starting up the allocator. This should
* be called when kva is ready for normal allocs.
*
* Arguments:
* None
*
* Returns:
* Nothing
*
* Discussion:
* uma_startup2 is called by kmeminit() to enable us of uma for malloc.
*/
void uma_startup2(void);
/*
* Reclaims unused memory for all zones
*
* Arguments:
* None
* Returns:
* None
*
* This should only be called by the page out daemon.
*/
void uma_reclaim(void);
/*
* Sets the alignment mask to be used for all zones requesting cache
* alignment. Should be called by MD boot code prior to starting VM/UMA.
*
* Arguments:
* align The alignment mask
*
* Returns:
* Nothing
*/
void uma_set_align(int align);
/*
* Switches the backing object of a zone
*
* Arguments:
* zone The zone to update.
* obj The VM object to use for future allocations.
* size The size of the object to allocate.
*
* Returns:
* 0 if kva space can not be allocated
* 1 if successful
*
* Discussion:
* A NULL object can be used and uma will allocate one for you. Setting
* the size will limit the amount of memory allocated to this zone.
*
*/
struct vm_object;
int uma_zone_set_obj(uma_zone_t zone, struct vm_object *obj, int size);
/*
* Sets a high limit on the number of items allowed in a zone
*
* Arguments:
* zone The zone to limit
* nitems The requested upper limit on the number of items allowed
*
* Returns:
* int The effective value of nitems after rounding up based on page size
*/
int uma_zone_set_max(uma_zone_t zone, int nitems);
/*
* Obtains the effective limit on the number of items in a zone
*
* Arguments:
* zone The zone to obtain the effective limit from
*
* Return:
* 0 No limit
* int The effective limit of the zone
*/
int uma_zone_get_max(uma_zone_t zone);
/*
* Obtains the approximate current number of items allocated from a zone
*
* Arguments:
* zone The zone to obtain the current allocation count from
*
* Return:
* int The approximate current number of items allocated from the zone
*/
int uma_zone_get_cur(uma_zone_t zone);
/*
* The following two routines (uma_zone_set_init/fini)
* are used to set the backend init/fini pair which acts on an
* object as it becomes allocated and is placed in a slab within
* the specified zone's backing keg. These should probably not
* be changed once allocations have already begun, but only be set
* immediately upon zone creation.
*/
void uma_zone_set_init(uma_zone_t zone, uma_init uminit);
void uma_zone_set_fini(uma_zone_t zone, uma_fini fini);
/*
* The following two routines (uma_zone_set_zinit/zfini) are
* used to set the zinit/zfini pair which acts on an object as
* it passes from the backing Keg's slab cache to the
* specified Zone's bucket cache. These should probably not
* be changed once allocations have already begun, but only be set
* immediately upon zone creation.
*/
void uma_zone_set_zinit(uma_zone_t zone, uma_init zinit);
void uma_zone_set_zfini(uma_zone_t zone, uma_fini zfini);
/*
* Replaces the standard page_alloc or obj_alloc functions for this zone
*
* Arguments:
* zone The zone whose backend allocator is being changed.
* allocf A pointer to the allocation function
*
* Returns:
* Nothing
*
* Discussion:
* This could be used to implement pageable allocation, or perhaps
* even DMA allocators if used in conjunction with the OFFPAGE
* zone flag.
*/
void uma_zone_set_allocf(uma_zone_t zone, uma_alloc allocf);
/*
* Used for freeing memory provided by the allocf above
*
* Arguments:
* zone The zone that intends to use this free routine.
* freef The page freeing routine.
*
* Returns:
* Nothing
*/
void uma_zone_set_freef(uma_zone_t zone, uma_free freef);
/*
* These flags are setable in the allocf and visible in the freef.
*/
#define UMA_SLAB_BOOT 0x01 /* Slab alloced from boot pages */
#define UMA_SLAB_KMEM 0x02 /* Slab alloced from kmem_map */
#define UMA_SLAB_KERNEL 0x04 /* Slab alloced from kernel_map */
#define UMA_SLAB_PRIV 0x08 /* Slab alloced from priv allocator */
#define UMA_SLAB_OFFP 0x10 /* Slab is managed separately */
#define UMA_SLAB_MALLOC 0x20 /* Slab is a large malloc slab */
/* 0x40 and 0x80 are available */
/*
* Used to pre-fill a zone with some number of items
*
* Arguments:
* zone The zone to fill
* itemcnt The number of items to reserve
*
* Returns:
* Nothing
*
* NOTE: This is blocking and should only be done at startup
*/
void uma_prealloc(uma_zone_t zone, int itemcnt);
/*
* Used to lookup the reference counter allocated for an item
* from a UMA_ZONE_REFCNT zone. For UMA_ZONE_REFCNT zones,
* reference counters are allocated for items and stored in
* the underlying slab header.
*
* Arguments:
* zone The UMA_ZONE_REFCNT zone to which the item belongs.
* item The address of the item for which we want a refcnt.
*
* Returns:
* A pointer to a u_int32_t reference counter.
*/
u_int32_t *uma_find_refcnt(uma_zone_t zone, void *item);
/*
* Used to determine if a fixed-size zone is exhausted.
*
* Arguments:
* zone The zone to check
*
* Returns:
* Non-zero if zone is exhausted.
*/
int uma_zone_exhausted(uma_zone_t zone);
int uma_zone_exhausted_nolock(uma_zone_t zone);
/*
* Exported statistics structures to be used by user space monitoring tools.
* Statistics stream consists of a uma_stream_header, followed by a series of
* alternative uma_type_header and uma_type_stat structures.
*/
#define UMA_STREAM_VERSION 0x00000001
struct uma_stream_header {
u_int32_t ush_version; /* Stream format version. */
u_int32_t ush_maxcpus; /* Value of MAXCPU for stream. */
u_int32_t ush_count; /* Number of records. */
u_int32_t _ush_pad; /* Pad/reserved field. */
};
#define UTH_MAX_NAME 32
#define UTH_ZONE_SECONDARY 0x00000001
struct uma_type_header {
/*
* Static per-zone data, some extracted from the supporting keg.
*/
char uth_name[UTH_MAX_NAME];
u_int32_t uth_align; /* Keg: alignment. */
u_int32_t uth_size; /* Keg: requested size of item. */
u_int32_t uth_rsize; /* Keg: real size of item. */
u_int32_t uth_maxpages; /* Keg: maximum number of pages. */
u_int32_t uth_limit; /* Keg: max items to allocate. */
/*
* Current dynamic zone/keg-derived statistics.
*/
u_int32_t uth_pages; /* Keg: pages allocated. */
u_int32_t uth_keg_free; /* Keg: items free. */
u_int32_t uth_zone_free; /* Zone: items free. */
u_int32_t uth_bucketsize; /* Zone: desired bucket size. */
u_int32_t uth_zone_flags; /* Zone: flags. */
u_int64_t uth_allocs; /* Zone: number of allocations. */
u_int64_t uth_frees; /* Zone: number of frees. */
u_int64_t uth_fails; /* Zone: number of alloc failures. */
u_int64_t uth_sleeps; /* Zone: number of alloc sleeps. */
u_int64_t _uth_reserved1[2]; /* Reserved. */
};
struct uma_percpu_stat {
u_int64_t ups_allocs; /* Cache: number of allocations. */
u_int64_t ups_frees; /* Cache: number of frees. */
u_int64_t ups_cache_free; /* Cache: free items in cache. */
u_int64_t _ups_reserved[5]; /* Reserved. */
};
#endif
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