sys/kern/kern_malloc.c

/*
 * Copyright (c) 1987, 1991 The Regents of the University of California.
 * 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, 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
 *
 *      from: @(#)kern_malloc.c 7.25 (Berkeley) 5/8/91
 *      $Id: kern_malloc.c,v 1.2 1993/10/16 15:24:21 rgrimes Exp $
 */

#include "param.h"
#include "proc.h"
#include "kernel.h"
#include "malloc.h"
#include "vm/vm.h"
#include "vm/vm_kern.h"

struct kmembuckets bucket[MINBUCKET + 16];
struct kmemstats kmemstats[M_LAST];
struct kmemusage *kmemusage;
char *kmembase, *kmemlimit;
char *memname[] = INITKMEMNAMES;

/*
 * Allocate a block of memory
 */
void *
malloc(size, type, flags)
        unsigned long size;
        int type, flags;
{
        register struct kmembuckets *kbp;
        register struct kmemusage *kup;
        long indx, npg, alloc, allocsize;
        int s;
        caddr_t va, cp, savedlist;
#ifdef KMEMSTATS
        register struct kmemstats *ksp = &kmemstats[type];

        if (((unsigned long)type) > M_LAST)
                panic("malloc - bogus type");
#endif

        indx = BUCKETINDX(size);
        kbp = &bucket[indx];
        s = splimp();
#ifdef KMEMSTATS
        while (ksp->ks_memuse >= ksp->ks_limit) {
                if (flags & M_NOWAIT) {
                        splx(s);
                        return ((void *) NULL);
                }
                if (ksp->ks_limblocks < 65535)
                        ksp->ks_limblocks++;
                tsleep((caddr_t)ksp, PSWP+2, memname[type], 0);
        }
#endif
        if (kbp->kb_next == NULL) {
                if (size > MAXALLOCSAVE)
                        allocsize = roundup(size, CLBYTES);
                else
                        allocsize = 1 << indx;
                npg = clrnd(btoc(allocsize));
                va = (caddr_t) kmem_malloc(kmem_map, (vm_size_t)ctob(npg),
                                           !(flags & M_NOWAIT));
                if (va == NULL) {
                        splx(s);
                        return ((void *) NULL);
                }
#ifdef KMEMSTATS
                kbp->kb_total += kbp->kb_elmpercl;
#endif
                kup = btokup(va);
                kup->ku_indx = indx;
                if (allocsize > MAXALLOCSAVE) {
                        if (npg > 65535)
                                panic("malloc: allocation too large");
                        kup->ku_pagecnt = npg;
#ifdef KMEMSTATS
                        ksp->ks_memuse += allocsize;
#endif
                        goto out;
                }
#ifdef KMEMSTATS
                kup->ku_freecnt = kbp->kb_elmpercl;
                kbp->kb_totalfree += kbp->kb_elmpercl;
#endif
                /*
                 * Just in case we blocked while allocating memory,
                 * and someone else also allocated memory for this
                 * bucket, don't assume the list is still empty.
                 */
                savedlist = kbp->kb_next;
                kbp->kb_next = va + (npg * NBPG) - allocsize;
                for (cp = kbp->kb_next; cp > va; cp -= allocsize)
                        *(caddr_t *)cp = cp - allocsize;
                *(caddr_t *)cp = savedlist;
        }
        va = kbp->kb_next;
        kbp->kb_next = *(caddr_t *)va;
#ifdef KMEMSTATS
        kup = btokup(va);
        if (kup->ku_indx != indx)
                panic("malloc: wrong bucket");
        if (kup->ku_freecnt == 0)
                panic("malloc: lost data");
        kup->ku_freecnt--;
        kbp->kb_totalfree--;
        ksp->ks_memuse += 1 << indx;
out:
        kbp->kb_calls++;
        ksp->ks_inuse++;
        ksp->ks_calls++;
        if (ksp->ks_memuse > ksp->ks_maxused)
                ksp->ks_maxused = ksp->ks_memuse;
#else
out:
#endif
        splx(s);
        return ((void *) va);
}

#ifdef DIAGNOSTIC
long addrmask[] = { 0x00000000,
        0x00000001, 0x00000003, 0x00000007, 0x0000000f,
        0x0000001f, 0x0000003f, 0x0000007f, 0x000000ff,
        0x000001ff, 0x000003ff, 0x000007ff, 0x00000fff,
        0x00001fff, 0x00003fff, 0x00007fff, 0x0000ffff,
};
#endif /* DIAGNOSTIC */

/*
 * Free a block of memory allocated by malloc.
 */
void
free(addr, type)
        void *addr;
        int type;
{
        register struct kmembuckets *kbp;
        register struct kmemusage *kup;
        long alloc, size;
        int s;
#ifdef KMEMSTATS
        register struct kmemstats *ksp = &kmemstats[type];
#endif

        kup = btokup(addr);
        size = 1 << kup->ku_indx;
#ifdef DIAGNOSTIC
        if (size > NBPG * CLSIZE)
                alloc = addrmask[BUCKETINDX(NBPG * CLSIZE)];
        else
                alloc = addrmask[kup->ku_indx];
        if (((u_long)addr & alloc) != 0) {
                printf("free: unaligned addr 0x%x, size %d, type %d, mask %d\n",
                        addr, size, type, alloc);
                panic("free: unaligned addr");
        }
#endif /* DIAGNOSTIC */
        kbp = &bucket[kup->ku_indx];
        s = splimp();
        if (size > MAXALLOCSAVE) {
                kmem_free(kmem_map, (vm_offset_t)addr, ctob(kup->ku_pagecnt));
#ifdef KMEMSTATS
                size = kup->ku_pagecnt << PGSHIFT;
                ksp->ks_memuse -= size;
                kup->ku_indx = 0;
                kup->ku_pagecnt = 0;
                if (ksp->ks_memuse + size >= ksp->ks_limit &&
                    ksp->ks_memuse < ksp->ks_limit)
                        wakeup((caddr_t)ksp);
                ksp->ks_inuse--;
                kbp->kb_total -= 1;
#endif
                splx(s);
                return;
        }
#ifdef KMEMSTATS
        kup->ku_freecnt++;
        if (kup->ku_freecnt >= kbp->kb_elmpercl)
                if (kup->ku_freecnt > kbp->kb_elmpercl)
                        panic("free: multiple frees");
                else if (kbp->kb_totalfree > kbp->kb_highwat)
                        kbp->kb_couldfree++;
        kbp->kb_totalfree++;
        ksp->ks_memuse -= size;
        if (ksp->ks_memuse + size >= ksp->ks_limit &&
            ksp->ks_memuse < ksp->ks_limit)
                wakeup((caddr_t)ksp);
        ksp->ks_inuse--;
#endif
        *(caddr_t *)addr = kbp->kb_next;
        kbp->kb_next = addr;
        splx(s);
}

/*
 * Initialize the kernel memory allocator
 */
kmeminit()
{
        register long indx;
        int npg;

#if     (MAXALLOCSAVE > MINALLOCSIZE * 32768)
                ERROR!_kmeminit:_MAXALLOCSAVE_too_big
#endif
#if     (MAXALLOCSAVE < CLBYTES-1)
                ERROR!_kmeminit:_MAXALLOCSAVE_too_small
#endif
        npg = VM_KMEM_SIZE/ NBPG;
        kmemusage = (struct kmemusage *) kmem_alloc(kernel_map,
                (vm_size_t)(npg * sizeof(struct kmemusage)));
        kmem_map = kmem_suballoc(kernel_map, (vm_offset_t *)&kmembase,
                (vm_offset_t *)&kmemlimit, (vm_size_t)(npg * NBPG), FALSE);
#ifdef KMEMSTATS
        for (indx = 0; indx < MINBUCKET + 16; indx++) {
                if (1 << indx >= CLBYTES)
                        bucket[indx].kb_elmpercl = 1;
                else
                        bucket[indx].kb_elmpercl = CLBYTES / (1 << indx);
                bucket[indx].kb_highwat = 5 * bucket[indx].kb_elmpercl;
        }
        for (indx = 0; indx < M_LAST; indx++)
                kmemstats[indx].ks_limit = npg * NBPG * 6 / 10;
#endif
}