09828ba947
shall not be called while holding cdev mutex. devfs_inos unrhdr has cdev as mutex, thus creating this LOR situation. Postpone calling free() in kern/subr_unit.c:alloc_unr() and nested functions until the unrhdr mutex is dropped. Save the freed items on the ppfree list instead, and provide the clean_unrhdrl() and clean_unrhdr() functions to clean the list. Call clean_unrhdrl() after devfs_create() calls immediately before dropping cdev mutex. devfs_create() is the only user of the alloc_unrl() in the tree. Reviewed by: phk Tested by: Peter Holm LOR: 80 Approved by: re (kensmith)
869 lines
19 KiB
C
869 lines
19 KiB
C
/*-
|
|
* Copyright (c) 2004 Poul-Henning Kamp
|
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* All rights reserved.
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*
|
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* Redistribution and use in source and binary forms, with or without
|
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* modification, are permitted provided that the following conditions
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* are met:
|
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* 1. Redistributions of source code must retain the above copyright
|
|
* notice, 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.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
|
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $FreeBSD$
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*
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*
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* Unit number allocation functions.
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*
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* These functions implement a mixed run-length/bitmap management of unit
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* number spaces in a very memory efficient manner.
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*
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* Allocation policy is always lowest free number first.
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*
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* A return value of -1 signals that no more unit numbers are available.
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*
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* There is no cost associated with the range of unitnumbers, so unless
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* the resource really is finite, specify INT_MAX to new_unrhdr() and
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* forget about checking the return value.
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*
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* If a mutex is not provided when the unit number space is created, a
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* default global mutex is used. The advantage to passing a mutex in, is
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* that the the alloc_unrl() function can be called with the mutex already
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* held (it will not be released by alloc_unrl()).
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*
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* The allocation function alloc_unr{l}() never sleeps (but it may block on
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* the mutex of course).
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*
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* Freeing a unit number may require allocating memory, and can therefore
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* sleep so the free_unr() function does not come in a pre-locked variant.
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*
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* A userland test program is included.
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*
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* Memory usage is a very complex function of the the exact allocation
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* pattern, but always very compact:
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* * For the very typical case where a single unbroken run of unit
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* numbers are allocated 44 bytes are used on i386.
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* * For a unit number space of 1000 units and the random pattern
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* in the usermode test program included, the worst case usage
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* was 252 bytes on i386 for 500 allocated and 500 free units.
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* * For a unit number space of 10000 units and the random pattern
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* in the usermode test program included, the worst case usage
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* was 798 bytes on i386 for 5000 allocated and 5000 free units.
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* * The worst case is where every other unit number is allocated and
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* the the rest are free. In that case 44 + N/4 bytes are used where
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* N is the number of the highest unit allocated.
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*/
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#include <sys/types.h>
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#include <sys/queue.h>
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#include <sys/bitstring.h>
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#ifdef _KERNEL
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#include <sys/param.h>
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#include <sys/malloc.h>
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#include <sys/kernel.h>
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#include <sys/systm.h>
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#include <sys/limits.h>
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#include <sys/lock.h>
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#include <sys/mutex.h>
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|
|
|
/*
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* In theory it would be smarter to allocate the individual blocks
|
|
* with the zone allocator, but at this time the expectation is that
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* there will typically not even be enough allocations to fill a single
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|
* page, so we stick with malloc for now.
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|
*/
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static MALLOC_DEFINE(M_UNIT, "Unitno", "Unit number allocation");
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|
|
#define Malloc(foo) malloc(foo, M_UNIT, M_WAITOK | M_ZERO)
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#define Free(foo) free(foo, M_UNIT)
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|
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|
static struct mtx unitmtx;
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|
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MTX_SYSINIT(unit, &unitmtx, "unit# allocation", MTX_DEF);
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|
|
#else /* ...USERLAND */
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|
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#include <stdio.h>
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|
#include <stdlib.h>
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|
#include <string.h>
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|
|
|
#define KASSERT(cond, arg) \
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|
do { \
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|
if (!(cond)) { \
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printf arg; \
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|
abort(); \
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|
} \
|
|
} while (0)
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|
|
|
static int no_alloc;
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|
#define Malloc(foo) _Malloc(foo, __LINE__)
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|
static void *
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|
_Malloc(size_t foo, int line)
|
|
{
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|
|
|
KASSERT(no_alloc == 0, ("malloc in wrong place() line %d", line));
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|
return (calloc(foo, 1));
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|
}
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|
#define Free(foo) free(foo)
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|
|
|
struct unrhdr;
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|
|
|
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|
struct mtx {
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|
int state;
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|
} unitmtx;
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|
|
|
static void
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|
mtx_lock(struct mtx *mp)
|
|
{
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|
KASSERT(mp->state == 0, ("mutex already locked"));
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|
mp->state = 1;
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|
}
|
|
|
|
static void
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|
mtx_unlock(struct mtx *mp)
|
|
{
|
|
KASSERT(mp->state == 1, ("mutex not locked"));
|
|
mp->state = 0;
|
|
}
|
|
|
|
#define MA_OWNED 9
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|
|
|
static void
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|
mtx_assert(struct mtx *mp, int flag)
|
|
{
|
|
if (flag == MA_OWNED) {
|
|
KASSERT(mp->state == 1, ("mtx_assert(MA_OWNED) not true"));
|
|
}
|
|
}
|
|
|
|
#define CTASSERT(foo)
|
|
|
|
#endif /* USERLAND */
|
|
|
|
/*
|
|
* This is our basic building block.
|
|
*
|
|
* It can be used in three different ways depending on the value of the ptr
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|
* element:
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|
* If ptr is NULL, it represents a run of free items.
|
|
* If ptr points to the unrhdr it represents a run of allocated items.
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|
* Otherwise it points to an bitstring of allocated items.
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|
*
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|
* For runs the len field is the length of the run.
|
|
* For bitmaps the len field represents the number of allocated items.
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|
*
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|
* The bitmap is the same size as struct unr to optimize memory management.
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|
*/
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|
struct unr {
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|
TAILQ_ENTRY(unr) list;
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|
u_int len;
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|
void *ptr;
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|
};
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|
|
|
struct unrb {
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|
u_char busy;
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|
bitstr_t map[sizeof(struct unr) - 1];
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|
};
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|
|
|
CTASSERT(sizeof(struct unr) == sizeof(struct unrb));
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|
|
|
/* Number of bits in the bitmap */
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|
#define NBITS ((int)sizeof(((struct unrb *)NULL)->map) * 8)
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|
|
|
/* Header element for a unr number space. */
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|
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|
struct unrhdr {
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|
TAILQ_HEAD(unrhd,unr) head;
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u_int low; /* Lowest item */
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|
u_int high; /* Highest item */
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|
u_int busy; /* Count of allocated items */
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|
u_int alloc; /* Count of memory allocations */
|
|
u_int first; /* items in allocated from start */
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|
u_int last; /* items free at end */
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|
struct mtx *mtx;
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|
TAILQ_HEAD(unrfr,unr) ppfree; /* Items to be freed after mtx
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|
lock dropped */
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|
};
|
|
|
|
|
|
#if defined(DIAGNOSTIC) || !defined(_KERNEL)
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|
/*
|
|
* Consistency check function.
|
|
*
|
|
* Checks the internal consistency as well as we can.
|
|
*
|
|
* Called at all boundaries of this API.
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|
*/
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|
static void
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|
check_unrhdr(struct unrhdr *uh, int line)
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|
{
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|
struct unr *up;
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|
struct unrb *ub;
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u_int x, y, z, w;
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|
y = uh->first;
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z = 0;
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TAILQ_FOREACH(up, &uh->head, list) {
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z++;
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if (up->ptr != uh && up->ptr != NULL) {
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|
ub = up->ptr;
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|
KASSERT (up->len <= NBITS,
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|
("UNR inconsistency: len %u max %d (line %d)\n",
|
|
up->len, NBITS, line));
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|
z++;
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|
w = 0;
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|
for (x = 0; x < up->len; x++)
|
|
if (bit_test(ub->map, x))
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|
w++;
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KASSERT (w == ub->busy,
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|
("UNR inconsistency: busy %u found %u (line %d)\n",
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|
ub->busy, w, line));
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y += w;
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|
} else if (up->ptr != NULL)
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|
y += up->len;
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|
}
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|
KASSERT (y == uh->busy,
|
|
("UNR inconsistency: items %u found %u (line %d)\n",
|
|
uh->busy, y, line));
|
|
KASSERT (z == uh->alloc,
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|
("UNR inconsistency: chunks %u found %u (line %d)\n",
|
|
uh->alloc, z, line));
|
|
}
|
|
|
|
#else
|
|
|
|
static __inline void
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|
check_unrhdr(struct unrhdr *uh, int line)
|
|
{
|
|
|
|
}
|
|
|
|
#endif
|
|
|
|
|
|
/*
|
|
* Userland memory management. Just use calloc and keep track of how
|
|
* many elements we have allocated for check_unrhdr().
|
|
*/
|
|
|
|
static __inline void *
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|
new_unr(struct unrhdr *uh, void **p1, void **p2)
|
|
{
|
|
void *p;
|
|
|
|
uh->alloc++;
|
|
KASSERT(*p1 != NULL || *p2 != NULL, ("Out of cached memory"));
|
|
if (*p1 != NULL) {
|
|
p = *p1;
|
|
*p1 = NULL;
|
|
return (p);
|
|
} else {
|
|
p = *p2;
|
|
*p2 = NULL;
|
|
return (p);
|
|
}
|
|
}
|
|
|
|
static __inline void
|
|
delete_unr(struct unrhdr *uh, void *ptr)
|
|
{
|
|
struct unr *up;
|
|
|
|
uh->alloc--;
|
|
up = ptr;
|
|
TAILQ_INSERT_TAIL(&uh->ppfree, up, list);
|
|
}
|
|
|
|
void
|
|
clean_unrhdrl(struct unrhdr *uh)
|
|
{
|
|
struct unr *up;
|
|
|
|
mtx_assert(uh->mtx, MA_OWNED);
|
|
while ((up = TAILQ_FIRST(&uh->ppfree)) != NULL) {
|
|
TAILQ_REMOVE(&uh->ppfree, up, list);
|
|
mtx_unlock(uh->mtx);
|
|
Free(up);
|
|
mtx_lock(uh->mtx);
|
|
}
|
|
|
|
}
|
|
|
|
void
|
|
clean_unrhdr(struct unrhdr *uh)
|
|
{
|
|
|
|
mtx_lock(uh->mtx);
|
|
clean_unrhdrl(uh);
|
|
mtx_unlock(uh->mtx);
|
|
}
|
|
|
|
/*
|
|
* Allocate a new unrheader set.
|
|
*
|
|
* Highest and lowest valid values given as paramters.
|
|
*/
|
|
|
|
struct unrhdr *
|
|
new_unrhdr(int low, int high, struct mtx *mutex)
|
|
{
|
|
struct unrhdr *uh;
|
|
|
|
KASSERT(low <= high,
|
|
("UNR: use error: new_unrhdr(%u, %u)", low, high));
|
|
uh = Malloc(sizeof *uh);
|
|
if (mutex != NULL)
|
|
uh->mtx = mutex;
|
|
else
|
|
uh->mtx = &unitmtx;
|
|
TAILQ_INIT(&uh->head);
|
|
TAILQ_INIT(&uh->ppfree);
|
|
uh->low = low;
|
|
uh->high = high;
|
|
uh->first = 0;
|
|
uh->last = 1 + (high - low);
|
|
check_unrhdr(uh, __LINE__);
|
|
return (uh);
|
|
}
|
|
|
|
void
|
|
delete_unrhdr(struct unrhdr *uh)
|
|
{
|
|
|
|
check_unrhdr(uh, __LINE__);
|
|
KASSERT(uh->busy == 0, ("unrhdr has %u allocations", uh->busy));
|
|
KASSERT(uh->alloc == 0, ("UNR memory leak in delete_unrhdr"));
|
|
KASSERT(TAILQ_FIRST(&uh->ppfree) == NULL,
|
|
("unrhdr has postponed item for free"));
|
|
Free(uh);
|
|
}
|
|
|
|
static __inline int
|
|
is_bitmap(struct unrhdr *uh, struct unr *up)
|
|
{
|
|
return (up->ptr != uh && up->ptr != NULL);
|
|
}
|
|
|
|
/*
|
|
* Look for sequence of items which can be combined into a bitmap, if
|
|
* multiple are present, take the one which saves most memory.
|
|
*
|
|
* Return (1) if a sequence was found to indicate that another call
|
|
* might be able to do more. Return (0) if we found no suitable sequence.
|
|
*
|
|
* NB: called from alloc_unr(), no new memory allocation allowed.
|
|
*/
|
|
static int
|
|
optimize_unr(struct unrhdr *uh)
|
|
{
|
|
struct unr *up, *uf, *us;
|
|
struct unrb *ub, *ubf;
|
|
u_int a, l, ba;
|
|
|
|
/*
|
|
* Look for the run of items (if any) which when collapsed into
|
|
* a bitmap would save most memory.
|
|
*/
|
|
us = NULL;
|
|
ba = 0;
|
|
TAILQ_FOREACH(uf, &uh->head, list) {
|
|
if (uf->len >= NBITS)
|
|
continue;
|
|
a = 1;
|
|
if (is_bitmap(uh, uf))
|
|
a++;
|
|
l = uf->len;
|
|
up = uf;
|
|
while (1) {
|
|
up = TAILQ_NEXT(up, list);
|
|
if (up == NULL)
|
|
break;
|
|
if ((up->len + l) > NBITS)
|
|
break;
|
|
a++;
|
|
if (is_bitmap(uh, up))
|
|
a++;
|
|
l += up->len;
|
|
}
|
|
if (a > ba) {
|
|
ba = a;
|
|
us = uf;
|
|
}
|
|
}
|
|
if (ba < 3)
|
|
return (0);
|
|
|
|
/*
|
|
* If the first element is not a bitmap, make it one.
|
|
* Trying to do so without allocating more memory complicates things
|
|
* a bit
|
|
*/
|
|
if (!is_bitmap(uh, us)) {
|
|
uf = TAILQ_NEXT(us, list);
|
|
TAILQ_REMOVE(&uh->head, us, list);
|
|
a = us->len;
|
|
l = us->ptr == uh ? 1 : 0;
|
|
ub = (void *)us;
|
|
ub->busy = 0;
|
|
if (l) {
|
|
bit_nset(ub->map, 0, a);
|
|
ub->busy += a;
|
|
} else {
|
|
bit_nclear(ub->map, 0, a);
|
|
}
|
|
if (!is_bitmap(uh, uf)) {
|
|
if (uf->ptr == NULL) {
|
|
bit_nclear(ub->map, a, a + uf->len - 1);
|
|
} else {
|
|
bit_nset(ub->map, a, a + uf->len - 1);
|
|
ub->busy += uf->len;
|
|
}
|
|
uf->ptr = ub;
|
|
uf->len += a;
|
|
us = uf;
|
|
} else {
|
|
ubf = uf->ptr;
|
|
for (l = 0; l < uf->len; l++, a++) {
|
|
if (bit_test(ubf->map, l)) {
|
|
bit_set(ub->map, a);
|
|
ub->busy++;
|
|
} else {
|
|
bit_clear(ub->map, a);
|
|
}
|
|
}
|
|
uf->len = a;
|
|
delete_unr(uh, uf->ptr);
|
|
uf->ptr = ub;
|
|
us = uf;
|
|
}
|
|
}
|
|
ub = us->ptr;
|
|
while (1) {
|
|
uf = TAILQ_NEXT(us, list);
|
|
if (uf == NULL)
|
|
return (1);
|
|
if (uf->len + us->len > NBITS)
|
|
return (1);
|
|
if (uf->ptr == NULL) {
|
|
bit_nclear(ub->map, us->len, us->len + uf->len - 1);
|
|
us->len += uf->len;
|
|
TAILQ_REMOVE(&uh->head, uf, list);
|
|
delete_unr(uh, uf);
|
|
} else if (uf->ptr == uh) {
|
|
bit_nset(ub->map, us->len, us->len + uf->len - 1);
|
|
ub->busy += uf->len;
|
|
us->len += uf->len;
|
|
TAILQ_REMOVE(&uh->head, uf, list);
|
|
delete_unr(uh, uf);
|
|
} else {
|
|
ubf = uf->ptr;
|
|
for (l = 0; l < uf->len; l++, us->len++) {
|
|
if (bit_test(ubf->map, l)) {
|
|
bit_set(ub->map, us->len);
|
|
ub->busy++;
|
|
} else {
|
|
bit_clear(ub->map, us->len);
|
|
}
|
|
}
|
|
TAILQ_REMOVE(&uh->head, uf, list);
|
|
delete_unr(uh, ubf);
|
|
delete_unr(uh, uf);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* See if a given unr should be collapsed with a neighbor.
|
|
*
|
|
* NB: called from alloc_unr(), no new memory allocation allowed.
|
|
*/
|
|
static void
|
|
collapse_unr(struct unrhdr *uh, struct unr *up)
|
|
{
|
|
struct unr *upp;
|
|
struct unrb *ub;
|
|
|
|
/* If bitmap is all set or clear, change it to runlength */
|
|
if (is_bitmap(uh, up)) {
|
|
ub = up->ptr;
|
|
if (ub->busy == up->len) {
|
|
delete_unr(uh, up->ptr);
|
|
up->ptr = uh;
|
|
} else if (ub->busy == 0) {
|
|
delete_unr(uh, up->ptr);
|
|
up->ptr = NULL;
|
|
}
|
|
}
|
|
|
|
/* If nothing left in runlength, delete it */
|
|
if (up->len == 0) {
|
|
upp = TAILQ_PREV(up, unrhd, list);
|
|
if (upp == NULL)
|
|
upp = TAILQ_NEXT(up, list);
|
|
TAILQ_REMOVE(&uh->head, up, list);
|
|
delete_unr(uh, up);
|
|
up = upp;
|
|
}
|
|
|
|
/* If we have "hot-spot" still, merge with neighbor if possible */
|
|
if (up != NULL) {
|
|
upp = TAILQ_PREV(up, unrhd, list);
|
|
if (upp != NULL && up->ptr == upp->ptr) {
|
|
up->len += upp->len;
|
|
TAILQ_REMOVE(&uh->head, upp, list);
|
|
delete_unr(uh, upp);
|
|
}
|
|
upp = TAILQ_NEXT(up, list);
|
|
if (upp != NULL && up->ptr == upp->ptr) {
|
|
up->len += upp->len;
|
|
TAILQ_REMOVE(&uh->head, upp, list);
|
|
delete_unr(uh, upp);
|
|
}
|
|
}
|
|
|
|
/* Merge into ->first if possible */
|
|
upp = TAILQ_FIRST(&uh->head);
|
|
if (upp != NULL && upp->ptr == uh) {
|
|
uh->first += upp->len;
|
|
TAILQ_REMOVE(&uh->head, upp, list);
|
|
delete_unr(uh, upp);
|
|
if (up == upp)
|
|
up = NULL;
|
|
}
|
|
|
|
/* Merge into ->last if possible */
|
|
upp = TAILQ_LAST(&uh->head, unrhd);
|
|
if (upp != NULL && upp->ptr == NULL) {
|
|
uh->last += upp->len;
|
|
TAILQ_REMOVE(&uh->head, upp, list);
|
|
delete_unr(uh, upp);
|
|
if (up == upp)
|
|
up = NULL;
|
|
}
|
|
|
|
/* Try to make bitmaps */
|
|
while (optimize_unr(uh))
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* Allocate a free unr.
|
|
*/
|
|
int
|
|
alloc_unrl(struct unrhdr *uh)
|
|
{
|
|
struct unr *up;
|
|
struct unrb *ub;
|
|
u_int x;
|
|
int y;
|
|
|
|
mtx_assert(uh->mtx, MA_OWNED);
|
|
check_unrhdr(uh, __LINE__);
|
|
x = uh->low + uh->first;
|
|
|
|
up = TAILQ_FIRST(&uh->head);
|
|
|
|
/*
|
|
* If we have an ideal split, just adjust the first+last
|
|
*/
|
|
if (up == NULL && uh->last > 0) {
|
|
uh->first++;
|
|
uh->last--;
|
|
uh->busy++;
|
|
return (x);
|
|
}
|
|
|
|
/*
|
|
* We can always allocate from the first list element, so if we have
|
|
* nothing on the list, we must have run out of unit numbers.
|
|
*/
|
|
if (up == NULL)
|
|
return (-1);
|
|
|
|
KASSERT(up->ptr != uh, ("UNR first element is allocated"));
|
|
|
|
if (up->ptr == NULL) { /* free run */
|
|
uh->first++;
|
|
up->len--;
|
|
} else { /* bitmap */
|
|
ub = up->ptr;
|
|
KASSERT(ub->busy < up->len, ("UNR bitmap confusion"));
|
|
bit_ffc(ub->map, up->len, &y);
|
|
KASSERT(y != -1, ("UNR corruption: No clear bit in bitmap."));
|
|
bit_set(ub->map, y);
|
|
ub->busy++;
|
|
x += y;
|
|
}
|
|
uh->busy++;
|
|
collapse_unr(uh, up);
|
|
return (x);
|
|
}
|
|
|
|
int
|
|
alloc_unr(struct unrhdr *uh)
|
|
{
|
|
int i;
|
|
|
|
mtx_lock(uh->mtx);
|
|
i = alloc_unrl(uh);
|
|
clean_unrhdrl(uh);
|
|
mtx_unlock(uh->mtx);
|
|
return (i);
|
|
}
|
|
|
|
/*
|
|
* Free a unr.
|
|
*
|
|
* If we can save unrs by using a bitmap, do so.
|
|
*/
|
|
static void
|
|
free_unrl(struct unrhdr *uh, u_int item, void **p1, void **p2)
|
|
{
|
|
struct unr *up, *upp, *upn;
|
|
struct unrb *ub;
|
|
u_int pl;
|
|
|
|
KASSERT(item >= uh->low && item <= uh->high,
|
|
("UNR: free_unr(%u) out of range [%u...%u]",
|
|
item, uh->low, uh->high));
|
|
check_unrhdr(uh, __LINE__);
|
|
item -= uh->low;
|
|
upp = TAILQ_FIRST(&uh->head);
|
|
/*
|
|
* Freeing in the ideal split case
|
|
*/
|
|
if (item + 1 == uh->first && upp == NULL) {
|
|
uh->last++;
|
|
uh->first--;
|
|
uh->busy--;
|
|
check_unrhdr(uh, __LINE__);
|
|
return;
|
|
}
|
|
/*
|
|
* Freeing in the ->first section. Create a run starting at the
|
|
* freed item. The code below will subdivide it.
|
|
*/
|
|
if (item < uh->first) {
|
|
up = new_unr(uh, p1, p2);
|
|
up->ptr = uh;
|
|
up->len = uh->first - item;
|
|
TAILQ_INSERT_HEAD(&uh->head, up, list);
|
|
uh->first -= up->len;
|
|
}
|
|
|
|
item -= uh->first;
|
|
|
|
/* Find the item which contains the unit we want to free */
|
|
TAILQ_FOREACH(up, &uh->head, list) {
|
|
if (up->len > item)
|
|
break;
|
|
item -= up->len;
|
|
}
|
|
|
|
/* Handle bitmap items */
|
|
if (is_bitmap(uh, up)) {
|
|
ub = up->ptr;
|
|
|
|
KASSERT(bit_test(ub->map, item) != 0,
|
|
("UNR: Freeing free item %d (bitmap)\n", item));
|
|
bit_clear(ub->map, item);
|
|
uh->busy--;
|
|
ub->busy--;
|
|
collapse_unr(uh, up);
|
|
return;
|
|
}
|
|
|
|
KASSERT(up->ptr == uh, ("UNR Freeing free item %d (run))\n", item));
|
|
|
|
/* Just this one left, reap it */
|
|
if (up->len == 1) {
|
|
up->ptr = NULL;
|
|
uh->busy--;
|
|
collapse_unr(uh, up);
|
|
return;
|
|
}
|
|
|
|
/* Check if we can shift the item into the previous 'free' run */
|
|
upp = TAILQ_PREV(up, unrhd, list);
|
|
if (item == 0 && upp != NULL && upp->ptr == NULL) {
|
|
upp->len++;
|
|
up->len--;
|
|
uh->busy--;
|
|
collapse_unr(uh, up);
|
|
return;
|
|
}
|
|
|
|
/* Check if we can shift the item to the next 'free' run */
|
|
upn = TAILQ_NEXT(up, list);
|
|
if (item == up->len - 1 && upn != NULL && upn->ptr == NULL) {
|
|
upn->len++;
|
|
up->len--;
|
|
uh->busy--;
|
|
collapse_unr(uh, up);
|
|
return;
|
|
}
|
|
|
|
/* Split off the tail end, if any. */
|
|
pl = up->len - (1 + item);
|
|
if (pl > 0) {
|
|
upp = new_unr(uh, p1, p2);
|
|
upp->ptr = uh;
|
|
upp->len = pl;
|
|
TAILQ_INSERT_AFTER(&uh->head, up, upp, list);
|
|
}
|
|
|
|
/* Split off head end, if any */
|
|
if (item > 0) {
|
|
upp = new_unr(uh, p1, p2);
|
|
upp->len = item;
|
|
upp->ptr = uh;
|
|
TAILQ_INSERT_BEFORE(up, upp, list);
|
|
}
|
|
up->len = 1;
|
|
up->ptr = NULL;
|
|
uh->busy--;
|
|
collapse_unr(uh, up);
|
|
}
|
|
|
|
void
|
|
free_unr(struct unrhdr *uh, u_int item)
|
|
{
|
|
void *p1, *p2;
|
|
|
|
WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "free_unr");
|
|
p1 = Malloc(sizeof(struct unr));
|
|
p2 = Malloc(sizeof(struct unr));
|
|
mtx_lock(uh->mtx);
|
|
free_unrl(uh, item, &p1, &p2);
|
|
clean_unrhdrl(uh);
|
|
mtx_unlock(uh->mtx);
|
|
if (p1 != NULL)
|
|
Free(p1);
|
|
if (p2 != NULL)
|
|
Free(p2);
|
|
}
|
|
|
|
#ifndef _KERNEL /* USERLAND test driver */
|
|
|
|
/*
|
|
* Simple stochastic test driver for the above functions
|
|
*/
|
|
|
|
static void
|
|
print_unr(struct unrhdr *uh, struct unr *up)
|
|
{
|
|
u_int x;
|
|
struct unrb *ub;
|
|
|
|
printf(" %p len = %5u ", up, up->len);
|
|
if (up->ptr == NULL)
|
|
printf("free\n");
|
|
else if (up->ptr == uh)
|
|
printf("alloc\n");
|
|
else {
|
|
ub = up->ptr;
|
|
printf("bitmap(%d) [", ub->busy);
|
|
for (x = 0; x < up->len; x++) {
|
|
if (bit_test(ub->map, x))
|
|
printf("#");
|
|
else
|
|
printf(" ");
|
|
}
|
|
printf("]\n");
|
|
}
|
|
}
|
|
|
|
static void
|
|
print_unrhdr(struct unrhdr *uh)
|
|
{
|
|
struct unr *up;
|
|
u_int x;
|
|
|
|
printf(
|
|
"%p low = %u high = %u first = %u last = %u busy %u chunks = %u\n",
|
|
uh, uh->low, uh->high, uh->first, uh->last, uh->busy, uh->alloc);
|
|
x = uh->low + uh->first;
|
|
TAILQ_FOREACH(up, &uh->head, list) {
|
|
printf(" from = %5u", x);
|
|
print_unr(uh, up);
|
|
if (up->ptr == NULL || up->ptr == uh)
|
|
x += up->len;
|
|
else
|
|
x += NBITS;
|
|
}
|
|
}
|
|
|
|
/* Number of unrs to test */
|
|
#define NN 10000
|
|
|
|
int
|
|
main(int argc __unused, const char **argv __unused)
|
|
{
|
|
struct unrhdr *uh;
|
|
u_int i, x, m, j;
|
|
char a[NN];
|
|
|
|
setbuf(stdout, NULL);
|
|
uh = new_unrhdr(0, NN - 1, NULL);
|
|
print_unrhdr(uh);
|
|
|
|
memset(a, 0, sizeof a);
|
|
|
|
fprintf(stderr, "sizeof(struct unr) %d\n", sizeof (struct unr));
|
|
fprintf(stderr, "sizeof(struct unrb) %d\n", sizeof (struct unrb));
|
|
fprintf(stderr, "sizeof(struct unrhdr) %d\n", sizeof (struct unrhdr));
|
|
fprintf(stderr, "NBITS %d\n", NBITS);
|
|
x = 1;
|
|
for (m = 0; m < NN * 100; m++) {
|
|
j = random();
|
|
i = (j >> 1) % NN;
|
|
#if 0
|
|
if (a[i] && (j & 1))
|
|
continue;
|
|
#endif
|
|
if (a[i]) {
|
|
printf("F %u\n", i);
|
|
free_unr(uh, i);
|
|
a[i] = 0;
|
|
} else {
|
|
no_alloc = 1;
|
|
i = alloc_unr(uh);
|
|
if (i != -1) {
|
|
a[i] = 1;
|
|
printf("A %u\n", i);
|
|
}
|
|
no_alloc = 0;
|
|
}
|
|
if (1) /* XXX: change this for detailed debug printout */
|
|
print_unrhdr(uh);
|
|
check_unrhdr(uh, __LINE__);
|
|
}
|
|
for (i = 0; i < NN; i++) {
|
|
if (a[i]) {
|
|
printf("C %u\n", i);
|
|
free_unr(uh, i);
|
|
print_unrhdr(uh);
|
|
}
|
|
}
|
|
print_unrhdr(uh);
|
|
delete_unrhdr(uh);
|
|
return (0);
|
|
}
|
|
#endif
|