This is the first part of the new kernel memory allocator. This replaces

malloc(9) and vm_zone with a slab like allocator.

Reviewed by:	arch@

1 files changed, 420 insertions, 0 deletions

diff --git a/sys/vm/uma.h b/sys/vm/uma.h
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+/*
+ * Copyright (c) 2002, Jeffrey Roberson <jroberson@chesapeake.net>
+ * 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
+ *
+ * Jeff Roberson <jroberson@chesapeake.net>
+*/
+
+#ifndef VM_UMA_H
+#define VM_UMA_H
+
+#include <sys/param.h>		/* For NULL */
+#include <sys/malloc.h>		/* For M_* */
+
+/* User visable 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;
+
+/* 
+ * 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
+ * 
+ * Returns:
+ *	Nothing
+ *
+ * Discussion:
+ *	The constructor is called just before the memory is returned
+ *	to the user. It may block if neccisary.
+ */
+typedef void (*uma_ctor)(void *mem, int size, void *arg);
+
+/*
+ * 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.
+ * 
+ * Returns:
+ *	Nothing
+ *
+ * Discussion:
+ *	The initializer is called when the memory is cached in the uma zone. 
+ *	this should be the same state that the destructor leaves the object in.
+ */
+typedef void (*uma_init)(void *mem, int size);
+
+/*
+ * 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 embeded 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 neccisary 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 corisponds 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, int size, uma_ctor ctor, uma_dtor dtor,
+			uma_init uminit, uma_fini fini, int align,
+			u_int16_t flags);
+
+/* Definitions for uma_zcreate flags */
+#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	/* Staticly 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! */
+
+/* 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	(16 - 1)		/* Cache line size align */
+
+/*
+ * Destroys a uma zone
+ *
+ * Arguments:
+ *	zone  The zone we want to destroy.
+ *	wait  This flag indicates whether or not we should wait for all
+ *		allocations to free, or return an errno on outstanding memory.
+ *
+ * Returns:
+ *	0 on successful completion, or EWOULDBLOCK if there are outstanding
+ *	allocations and the wait flag is M_NOWAIT
+ */
+
+int uma_zdestroy(uma_zone_t zone, int wait);
+
+/*
+ * Allocates an item out of a zone
+ *
+ * Arguments:
+ *	zone  The zone we are allocating from
+ *	arg   This data is passed to the ctor function
+ *	wait  This flag indicates whether or not we are allowed to block while
+ *		allocating memory for this zone should we run out.
+ *
+ * Returns:
+ *	A non null pointer to an initialized element from the zone is
+ *	garanteed 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 wait);
+
+/*
+ * 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 wait);
+
+static __inline void *
+uma_zalloc(uma_zone_t zone, int wait)
+{
+	return uma_zalloc_arg(zone, NULL, wait);
+}
+
+/*
+ * 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)
+{
+	return 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 alloced 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 * UMA_BOOT_PAGES bytes. (see uma_int.h)
+ *
+ */
+
+void uma_startup(void *bootmem);
+
+/*
+ * Finishes starting up the allocator.  This should
+ * be called when kva is ready for normal allocs.
+ *
+ * Arguments:
+ *	hash   An area of memory that will become the malloc hash
+ *	elems  The number of elements in this array
+ *
+ * Returns:
+ *	Nothing
+ *
+ * Discussion:
+ *	uma_startup2 is called by kmeminit() to prepare the malloc
+ *	hash bucket, and enable use of uma for malloc ops.
+ */
+ 
+void uma_startup2(void *hash, u_long elems);
+
+/*
+ * Reclaims unused memory for all zones
+ *
+ * Arguments:
+ *	None
+ * Returns:
+ *	None
+ *
+ * This should only be called by the page out daemon.
+ */
+
+void uma_reclaim(void);
+
+/*
+ * Switches the backing object of a zone
+ *
+ * Arguments:
+ *	zone  The zone to update
+ *	obj   The obj 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);
+
+
+/*
+ * Replaces the standard page_alloc or obj_alloc functions for this zone
+ *
+ * Arguments:
+ *	zone   The zone whos back end 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 visable 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_KMAP	0x04		/* Slab alloced from kernel_map */
+#define UMA_SLAB_PRIV	0x08		/* Slab alloced from priv allocator */
+#define UMA_SLAB_OFFP	0x10		/* Slab is managed seperately  */
+#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);
+
+
+#endif